draft-ietf-sigtran-m3ua-05.txt   draft-ietf-sigtran-m3ua-06.txt 
Network Working Group G. Sidebottom, L. Ong, Guy Mousseau Network Working Group Greg Sidebottom (Editor)
INTERNET-DRAFT Nortel Networks INTERNET-DRAFT Guy Mousseau
Nortel Networks
Lyndon Ong
Point Reyes Networks
Ian Rytina Ian Rytina
Ericsson Ericsson
Hanns-Juergen Schwarzbauer, Klaus Gradischnig Hanns-Juergen Schwarzbauer
Klaus Gradischnig
Siemens Siemens
Ken Morneault Ken Morneault
Cisco Cisco
Mallesh Kalla Mallesh Kalla
Telcordia Telcordia
Normand Glaude Normand Glaude
Performance Technologies Performance Technologies
Expires in six months Nov 2000 Expires in six months Feb 2001
SS7 MTP3-User Adaptation Layer (M3UA) SS7 MTP3-User Adaptation Layer (M3UA)
<draft-ietf-sigtran-m3ua-05.txt> <draft-ietf-sigtran-m3ua-06.txt>
Status of This Memo Status of This Memo
This document is an Internet-Draft and is in full conformance with all This document is an Internet-Draft and is in full conformance with all
provisions of Section 10 of RFC 2026. Internet-Drafts are working provisions of Section 10 of RFC 2026. Internet-Drafts are working
documents of the Internet Engineering Task Force (IETF), its areas, and documents of the Internet Engineering Task Force (IETF), its areas, and
its working groups. Note that other groups may also distribute working its working groups. Note that other groups may also distribute working
documents as Internet-Drafts. documents as Internet-Drafts.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
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munnari.oz.au (Pacific Rim), ftp.ietf.org (US East Coast), or munnari.oz.au (Pacific Rim), ftp.ietf.org (US East Coast), or
ftp.isi.edu (US West Coast). ftp.isi.edu (US West Coast).
Abstract Abstract
This Internet Draft defines a protocol for supporting the transport of This Internet Draft defines a protocol for supporting the transport of
any SS7 MTP3-User signalling (e.g., ISUP and SCCP messages) over IP any SS7 MTP3-User signalling (e.g., ISUP and SCCP messages) over IP
using the services of the Stream Control Transmission Protocol. Also, using the services of the Stream Control Transmission Protocol. Also,
provision is made for protocol elements that enable a seamless provision is made for protocol elements that enable a seamless
operation of the MTP3-User peers in the SS7 and IP domains. This operation of the MTP3-User peers in the SS7 and IP domains. This
protocol would be used between a Signalling Gateway (SG) and a Media protocol would be used between a Signalling Gateway (SG) and a Media
Gateway Controller (MGC) or IP-resident Database. It is assumed that Gateway Controller (MGC) or IP-resident Database. It is assumed that
the SG receives SS7 signalling over a standard SS7 interface using the the SG receives SS7 signalling over a standard SS7 interface using the
SS7 Message Transfer Part (MTP) to provide transport. SS7 Message Transfer Part (MTP) to provide transport.
TABLE OF CONTENTS TABLE OF CONTENTS
1. Introduction.......................................................3 1. Introduction.......................................................4
1.1 Scope.........................................................3 1.1 Scope.........................................................4
1.2 Terminology...................................................3 1.2 Terminology...................................................4
1.3 M3UA Overview.................................................5 1.3 M3UA Overview.................................................6
1.4 Functional Areas.............................................10 1.4 Functional Areas.............................................12
1.5 Sample Configurations........................................18 1.5 Sample Configurations........................................23
1.6 Definition of M3UA Boundaries................................21 1.6 Definition of M3UA Boundaries................................26
2. Conventions.......................................................22 2. Conventions.......................................................29
3. M3UA Protocol Elements............................................22 3. M3UA Protocol Elements............................................29
3.1 Common Message Header........................................22 3.1 Common Message Header........................................29
3.2 Variable-Length Parameter Format 3.2 Variable-Length Parameter....................................32
3.3 Transfer Messages............................................24 3.3 Transfer Messages............................................33
3.4 SS7 Signalling Network management (SSNM) Messages............26 3.4 SS7 Signalling Network management (SSNM) Messages............36
3.5 Application Server Process Maintenance Messages..............32 3.5 Application Server Process Maintenance (ASPM) Messages.......44
3.6 Management Messages..........................................40 3.6 Management Messages..........................................60
4. Procedures........................................................44 4. Procedures........................................................63
4.1 Procedures to Support the Services of the M3UA Layer.........44 4.1 Procedures to Support the Services of the M3UA Layer.........63
4.2 Procedures to Support the M3UA Services in Section 1.4.2.....44 4.2 Receipt of M3UA Peer Management Messages.....................65
4.3 Procedures to Support the M3UA Services in Section 1.4.4.....45 4.3 Procedures to support the M3UA Management services...........66
4.4 Procedures to Support the M3UA Services in Section 1.4.3.....52 4.4 Procedures to Support the M3UA Services......................78
5. Examples of M3UA Procedures.......................................54 5. Examples of M3UA Procedures.......................................81
5.1 Establishment of Association and Traffic 5.1 Establishment of Association and Traffic
Between SGs and ASPs.........................................54 Between SGs and ASPs.........................................81
5.2 ASP traffic Fail-over Examples...............................56 5.2 ASP traffic Fail-over Examples...............................86
5.3 M3UA/MTP3-User Boundary Examples.............................57 5.3 M3UA/MTP3-User Boundary Examples.............................87
6. Security..........................................................61 6. Security..........................................................91
6.1 Introduction.................................................61 6.1 Introduction.................................................91
6.2 Threats......................................................61 6.2 Threats......................................................91
6.3 Protecting Confidentiality...................................62 6.3 Protecting Confidentiality...................................91
7. IANA Considerations...............................................62 7. IANA Considerations...............................................92
7.1 SCTP Payload Protocol Identifier.............................62 7.1 SCTP Payload Protocol Identifier.............................92
7.2 M3UA Protocol Extensions.....................................62 7.2 M3UA Protocol Extensions.....................................92
8. Acknowledgements..................................................62 8. Acknowledgements..................................................93
9. References........................................................62 9. References........................................................93
10. Author's Addresses...............................................65 10. Author's Addresses...............................................95
1. Introduction 1. Introduction
1.1 Scope 1.1 Scope
There is a need for SCN signalling protocol delivery from an SS7 There is a need for Switched Circuit Network (SCN) signalling protocol
Signalling Gateway (SG) to a Media Gateway Controller (MGC) or IP- delivery from an SS7 Signalling Gateway (SG) to a Media Gateway
resident Database as described in the Framework Architecture for Controller (MGC) or IP-resident Database as described in the Framework
Signalling Transport [1]. The delivery mechanism should meet the Architecture for Signalling Transport [1]. The delivery mechanism
following criteria: SHOULD meet the following criteria:
* Support for the transfer of all SS7 MTP3-User Part messages (e.g., * Support for the transfer of all SS7 MTP3-User Part messages (e.g.,
ISUP, SCCP, TUP, etc.) ISUP, SCCP, TUP, etc.)
* Support for the seamless operation of MTP3-User protocol peers * Support for the seamless operation of MTP3-User protocol peers
* Support for the management of SCTP transport associations and * Support for the management of SCTP transport associations and
traffic between an SG and one or more MGCs or IP-resident Databases traffic between an SG and one or more MGCs or IP-resident Databases
* Support for MGC or IP-resident Database process fail-over and load- * Support for MGC or IP-resident Database process fail-over and load-
sharing sharing
* Support for the asynchronous reporting of status changes to * Support for the asynchronous reporting of status changes to
management management
In simplistic transport terms, the SG will terminate SS7 MTP2 and MTP3 In simplistic transport terms, the SG will terminate SS7 MTP2 and MTP3
protocol layers and deliver ISUP, SCCP and/or any other MTP3-User protocol layers and deliver ISUP, SCCP and/or any other MTP3-User
protocol messages over SCTP transport associations to MTP3-User peers protocol messages, as well as certain MTP network management events,
in MGCs or IP-resident Databases. over SCTP transport associations to MTP3-User peers in MGCs or IP-
resident Databases.
1.2 Terminology 1.2 Terminology
Application Server (AS) - A logical entity serving a specific Routing Application Server (AS) - A logical entity serving a specific Routing
Key. An example of an Application Server is a virtual switch element Key. An example of an Application Server is a virtual switch element
handling all call processing for a unique range of PSTN trunks, handling all call processing for a unique range of PSTN trunks,
identified by an SS7 DPC/OPC/CIC_range. Another example is a virtual identified by an SS7 DPC/OPC/CIC_range. Another example is a virtual
database element, handling all HLR transactions for a particular SS7 database element, handling all HLR transactions for a particular SS7
DPC/OPC/SCCP_SSN combination. The AS contains a set of one or more DPC/OPC/SCCP_SSN combination. The AS contains a set of one or more
unique Application Server Processes, of which one or more is normally unique Application Server Processes, of which one or more is normally
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Application Server Process (ASP) - A process instance of an Application Application Server Process (ASP) - A process instance of an Application
Server. An Application Server Process serves as an active or standby Server. An Application Server Process serves as an active or standby
process of an Application Server (e.g., part of a distributed virtual process of an Application Server (e.g., part of a distributed virtual
switch or database). Examples of ASPs are processes (or process switch or database). Examples of ASPs are processes (or process
instances) of MGCs, IP SCPs or IP HLRs. An ASP contains an SCTP end- instances) of MGCs, IP SCPs or IP HLRs. An ASP contains an SCTP end-
point and may be configured to process signalling traffic within more point and may be configured to process signalling traffic within more
than one Application Server. than one Application Server.
Association - An association refers to an SCTP association. The Association - An association refers to an SCTP association. The
association provides the transport for MTP3-User protocol data units association provides the transport for the delivery of MTP3-User
and M3UA adaptation layer peer messages. protocol data units and M3UA adaptation layer peer messages.
IP Server Process (IPSP) - A process instance of an IP-based IP Server Process (IPSP) - A process instance of an IP-based
application. An IPSP is essentially the same as an ASP, except that it application. An IPSP is essentially the same as an ASP, except that it
uses M3UA in a point-to-point fashion. Conceptually, an IPSP does not
uses MU3A in a peer-to-peer fashion. Conceptually, an IPSP does not use the services of a Signalling Gateway.
use the services of a signalling gateway.
Signalling Gateway Process (SGP) - A process instance of a Signalling Signalling Gateway Process (SGP) - A process instance of a Signalling
Gateway. It serves as an active, standby or load-sharing process of a Gateway. It serves as an active, standby or load-sharing process of a
Signalling Gateway. Signalling Gateway.
Signalling Process - A process instance that uses M3UA to communicate Signalling Process - A process instance that uses M3UA to communicate
with other signalling process. An ASP, a signalling gateway process with other signalling process. An ASP, a signalling gateway process
and an IPSP are all signalling processes. and an IPSP are all signalling processes.
Routing Key: A Routing Key describes a set of SS7 parameter and Routing Key: A Routing Key describes a set of SS7 parameters and
parameter values that uniquely define the range of signalling traffic parameter values that uniquely define the range of signalling traffic
to be handled by a particular Application Server. For example, where to be handled by a particular Application Server. Parameters within the
all traffic directed to an SS7 DPC, OPC and ISUP CIC_range(s) or SCCP Routing Key cannot extend across more than a single SS7 Destination
SSN is to be sent to a particular Application Server, that SS7 data Point Code.
defines the associated Routing Key. Routing Keys are unique in the
sense that a received SS7 signalling message cannot be directed to more
than one Routing Key. Also, a Routing Key cannot extend across more
than a single SS7 DPC, in order to more easily support SS7 Management
procedures. It is not necessary for the parameter range values within
a particular Routing Key to be contiguous. For example, an ASP could
be configured to support call processing for multiple ranges of PSTN
trunks that are not represented by contiguous CIC values.
Routing Context - An Application Server Process may be configured to Routing Context - A value that uniquely identifies a Routing Key.
process signalling traffic related to more than one Application Server, Routing Context values are either configured using a configuration
over a single SCTP Association. At an ASP, the Routing Context management interface, or by using the routing key management procedures
parameter uniquely identifies the range of signalling traffic defined in this document.
associated with each Application Server that the ASP is configured to
receive. There is a 1:1 relationship between a received Routing
Context value and a Routing Key entry at the sending node. Therefore
the Routing Context can be viewed as an index into a sending node's
Message Distribution Table containing the Routing Key entries.
Fail-over - The capability to re-route signalling traffic as required Fail-over - The capability to re-route signalling traffic as required
to an alternate Application Server Process, or group of ASPs, within an to an alternate Application Server Process, or group of ASPs, within an
Application Server in the event of failure or unavailability of a Application Server in the event of failure or unavailability of a
currently used Application Server Process. Fail-back may apply upon currently used Application Server Process. Fail-over also applies upon
the return to service of a previously unavailable Application Server the return to service of a previously unavailable Application Server
Process. Process.
Signalling Point Management Cluster (SPMC) - The complete set of Signalling Point Management Cluster (SPMC) - The complete set of
Application Servers represented to the SS7 network under one specific Application Servers represented to the SS7 network under one specific
SS7 Point Code of one specific Network Appearance. SPMCs are used to SS7 Point Code of one specific Network Appearance. SPMCs are used to
sum the availability / congestion / User_Part status of an SS7 sum the availability / congestion / User_Part status of an SS7
destination point code that is distributed in the IP domain, for the destination point code that is distributed in the IP domain, for the
purpose of supporting MTP3 management procedures at an SG. In some purpose of supporting MTP3 management procedures at an SG. In some
cases, the SG itself may also be a member of the SPMC. In this case, cases, the SG itself may also be a member of the SPMC. In this case,
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- Sequenced delivery of user messages within multiple streams, - Sequenced delivery of user messages within multiple streams,
with an option for order-of-arrival delivery of individual with an option for order-of-arrival delivery of individual
user messages, user messages,
- Optional multiplexing of user messages into SCTP datagrams; - Optional multiplexing of user messages into SCTP datagrams;
- Network-level fault tolerance through support of multi-homing - Network-level fault tolerance through support of multi-homing
at either or both ends of an association; at either or both ends of an association;
- Resistance to flooding and masquerade attacks; and - Resistance to flooding and masquerade attacks; and
- Data segmentation to conform to discovered path MTU size. - Data segmentation to conform to discovered path MTU size.
Under certain scenarios, such as back-to-back connections without Under certain scenarios, such as back-to-back connections without
redundancy requirements, the SCTP functions above may not be necessary. redundancy requirements, the SCTP functions above MAY NOT be a
In these cases, it is acceptable to use TCP as the underlying common requirement and TCP can be used as the underlying common transport
transport protocol. protocol.
1.3.2 Services Provided by the M3UA Layer 1.3.2 Services Provided by the M3UA Layer
The M3UA Layer at an ASP provides the equivalent set of primitives at The M3UA Layer at an ASP or IPSP provides the equivalent set of
its upper layer to the MTP3-Users as provided by the MTP Level 3 to its primitives at its upper layer to the MTP3-Users as provided by the MTP
local users at an SS7 SEP. In this way, the ISUP and/or SCCP layer at Level 3 to its local MTP3-Users at an SS7 SEP. In this way, the ISUP
an ASP is unaware that the expected MTP3 services are offered remotely and/or SCCP layer at an ASP or IPSP is unaware that the expected MTP3
from an MTP3 Layer at an SG, and not by a local MTP3 layer. The MTP3 services are offered remotely from an MTP3 Layer at an SG, and not by a
layer at an SG may also be unaware that its local users are actually local MTP3 layer. The MTP3 layer at an SG may also be unaware that its
remote user parts over M3UA. In effect, the M3UA extends access to the local users are actually remote user parts over M3UA. In effect, the
MTP3 layer services to a remote IP-based application. The M3UA does M3UA extends access to the MTP3 layer services to a remote IP-based
not itself provide the MTP3 services. In the case where an ASP is application. The M3UA does not itself provide the MTP3 services.
connected to more than one SG, however, the M3UA must maintain the However, in the case where an ASP is connected to more than one SG, the
status of configured SS7 destinations and route messages according to M3UA Layer at an ASP must maintain the status of configured SS7
availability/congestion status of the routes to these destinations. destinations and route messages according to the availability /
congestion status of the routes to these destinations via each SG.
The M3UA Layer may also be used for point-to-point signalling between The M3UA Layer may also be used for point-to-point signalling between
two IP Server Processes (IPSPs). In this case, the M3UA provides the two IP Server Processes (IPSPs). In this case, the M3UA provides the
same set of primitives and services at its upper layer as the MTP3. same set of primitives and services at its upper layer as the MTP3.
However, in this case the expected MTP3 services are not offered However, in this case the expected MTP3 services are not offered
remotely from an SG. The MTP3 services are provided but the procedures remotely from an SG. The MTP3 services are provided but the procedures
to support these services are a subset of the MTP3 procedures due to to support these services are a subset of the MTP3 procedures due to
the simplified point-to-point nature of the IPSP to IPSP relationship. the simplified point-to-point nature of the IPSP to IPSP relationship.
1.3.2.1 Support for the transport of MTP3-User Messages 1.3.2.1 Support for the transport of MTP3-User Messages
The M3UA provides the transport of MTP-TRANSFER primitives across an The M3UA provides the transport of MTP-TRANSFER primitives across an
established SCTP association between an SG and an ASP or between established SCTP association between an SG and an ASP or between IPSPs.
IPSPs.
The MTP-TRANSFER primitive information is encoded as in MTP3-User The MTP-TRANSFER primitive information is encoded as in MTP3-User
messages. In this way, the SCCP and ISUP messages received from the messages. In this way, the SCCP and ISUP messages received from the
SS7 network by the SG are not re-encoded into a different format for SS7 network by the SG are not re-encoded into a different format for
transport between the M3UA peers. The MTP3 Service Information Octet transport between the M3UA peers. The MTP3 Service Information Octet
(SIO) and Routing Label (OPC, DPC, and SLS) are included, encoded as (SIO) and Routing Label (OPC, DPC, and SLS) are included, encoded as
expected by the MTP3-User protocol layer. expected by the MTP3 and MTP3-User protocol layer.
At an ASP, in the case where a destination is reachable via multiple At an ASP, in the case where a destination is reachable via multiple
SGs, the M3UA must also choose via which SG the message is to be routed SGs, the M3UA must also choose via which SG the message is to be routed
or support load balancing across the SGs, ensuring that no mis- or support load balancing across the SGs, ensuring that no mis-
sequencing occurs. sequencing occurs.
The M3UA does not impose a 272-octet user information block limit as The M3UA does not impose a 272-octet signaling information field (SIF)
specified by the SS7 MTP Level 3 protocol. Larger information blocks length limit as specified by the SS7 MTP Level 2 protocol [14] [15]
can be accommodated directly by M3UA/SCTP, without the need for an [16]. Larger information blocks can be accommodated directly by
upper layer segmentation/re-assembly procedure as specified in recent M3UA/SCTP, without the need for an upper layer segmentation/re-assembly
SCCP or ISUP versions. However, in the context of an SG, the maximum procedure as specified in recent SCCP or ISUP versions. However, in
272-octet block size must be followed when inter-working to a SS7 the context of an SG, the maximum 272-octet block size must be followed
network that does not support the transfer of larger information blocks when inter-working to a SS7 network that does not support the transfer
to the final destination. This avoids potential ISUP or SCCP of larger information blocks to the final destination. This avoids
fragmentation requirements at the SG. However, if the SS7 network is potential ISUP or SCCP fragmentation requirements at the SG. However,
provisioned to support the Broadband MTP [20] to the final SS7 if the SS7 network is provisioned to support the Broadband MTP [20] to
destination, the information block size limit may be increased past 272 the final SS7 destination, the information block size limit may be
octets. increased past 272 octets.
1.3.2.2 Native Management Functions 1.3.2.2 Native Management Functions
The M3UA provides management of the underlying SCTP transport protocol The M3UA provides management of the underlying SCTP transport protocol
to ensure that SG-ASP and IPSP-IPSP transport is available to the to ensure that SG-ASP and IPSP-IPSP transport is available to the
degree called for by the MTP3-User signalling applications. degree called for by the MTP3-User signalling applications.
The M3UA provides the capability to indicate errors associated with The M3UA provides the capability to indicate errors associated with
received M3UA messages and to notify, as appropriate, local management received M3UA messages and to notify, as appropriate, local management
and/or the peer M3UA. and/or the peer M3UA.
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- Providing an indication to MTP3-Users at an ASP that a remote - Providing an indication to MTP3-Users at an ASP that a remote
destination in the SS7 network is not reachable. destination in the SS7 network is not reachable.
- Providing an indication to MTP3-Users at an ASP that a remote - Providing an indication to MTP3-Users at an ASP that a remote
destination in the SS7 network is now reachable. destination in the SS7 network is now reachable.
- Providing an indication to MTP3-Users at an ASP that messages to a - Providing an indication to MTP3-Users at an ASP that messages to a
remote MTP3-User peer in the SS7 network are experiencing SS7 remote MTP3-User peer in the SS7 network are experiencing SS7
congestion. congestion.
- Providing an indication to MTP3-Users at an ASP that the routes to
a remote MTP3-User peer in the SS7 network are restricted.
- Providing an indication to MTP3-Users at an ASP that a remote MTP3- - Providing an indication to MTP3-Users at an ASP that a remote MTP3-
User peer is unavailable. User peer is unavailable.
The M3UA layer at an ASP may initiate an audit of the availability or The M3UA layer at an ASP may initiate an audit of the availability, the
the congested state of remote SS7 destinations. This information is restricted or the congested state of remote SS7 destinations. This
requested from the M3UA at the SG. information is requested from the M3UA at the SG.
The M3UA layer at an ASP may also indicate to the SG that the M3UA The M3UA layer at an ASP may also indicate to the SG that the M3UA
itself or the ASP or the ASP's host is congested. itself or the ASP or the ASP's Host is congested.
1.3.2.4 Support for the management of SCTP associations between the SG 1.3.2.4 Support for the management of SCTP associations between the SG
and ASPs. and ASPs.
The M3UA layer at the SG maintains the availability state of all The M3UA layer at the SG maintains the availability state of all
configured local and remote ASPs, in order to manage the SCTP configured remote ASPs, in order to manage the SCTP Associations and
Associations and the traffic between the M3UA peers. As well, the the traffic between the M3UA peers. As well, the active/inactive and
active/inactive state of local and remote ASPs is also maintained. congestion state of remote ASPs is maintained.
The M3UA layer may be instructed by local management to establish an The M3UA layer MAY be instructed by local management to establish an
SCTP association to a peer M3UA node. This can be achieved using the SCTP association to a peer M3UA node. This can be achieved using the
M-SCTP ESTABLISH primitive to request, indicate and confirm the M-SCTP ESTABLISH primitive to request, indicate and confirm the
establishment of an SCTP association with a peer M3UA node. In order establishment of an SCTP association with a peer M3UA node. In order
to avoid redundant SCTP associations between two M3UA peers, one side to avoid redundant SCTP associations between two M3UA peers, one side
must be designated to establish the SCTP association or the mutual SCTP (client) must be designated to establish the SCTP association, or M3UA
endpoint addresses must be pre-configured. configuration knowledge maintained to detect redundant associations
(e.g., via knowledge of the expected local and remote SCTP endpoint
addresses).
The M3UA layer may also need to inform local management of the status The M3UA layer MAY also need to inform local management of the status
of the underlying SCTP associations using the M-SCTP STATUS request and of the underlying SCTP associations using the M-SCTP STATUS request and
indication primitive. For example, the M3UA may inform local management indication primitive. For example, the M3UA MAY inform local management
of the reason for the release of an SCTP association, determined either of the reason for the release of an SCTP association, determined either
locally within the M3UA layer or by a primitive from the SCTP. locally within the M3UA layer or by a primitive from the SCTP.
Also the M3UA layer may need to inform the local management of the Also the M3UA layer may need to inform the local management of the
change in status of an ASP or AS. This may be achieved using the M-ASP change in status of an ASP or AS. This may be achieved using the M-ASP
STATUS request or M-AS STATUS request primitives. STATUS request or M-AS STATUS request primitives.
1.3.2.5 Support for the management of connections to multiple SGs 1.3.2.5 Support for the management of connections to multiple SGs
As shown in Figure 1 an ASP may be connected to multiple SGs. In such a As shown in Figure 1 an ASP may be connected to multiple SGs. In such a
case a particular SS7 destination may be reachable via more than SG, case a particular SS7 destination may be reachable via more than SG,
i.e., via more than one route. As MTP3 users only maintain status on a i.e., via more than one route. As MTP3 users only maintain status on a
destination and not on a route basis M3UA must maintain the status destination and not on a route basis, M3UA must maintain the status
(availability and/or congestion of route to destination) of the (availability, restriction, and/or congestion of route to destination)
individual routes, derive the overall status of the destination from of the individual routes, derive the overall availability or congestion
the status of the individual routes, and inform the MTP3 users of this status of the destination from the status of the individual routes, and
derived status whenever it changes. inform the MTP3 users of this derived status whenever it changes.
1.3.3 Signalling Network Architecture 1.3.3 Signalling Network Architecture
A Signalling Gateway is used to support the transport of MTP3-User A Signalling Gateway is used to support the transport of MTP3-User
signalling traffic received from the SS7 network to multiple signalling traffic received from the SS7 network to multiple
distributed ASPs (e.g., MGCs and IP Databases). Clearly, the M3UA distributed ASPs (e.g., MGCs and IP Databases). Clearly, the M3UA
protocol is not designed to meet the performance and reliability protocol is not designed to meet the performance and reliability
requirements for such transport by itself. However, the conjunction of requirements for such transport by itself. However, the conjunction of
distributed architecture and redundant networks does allow for a distributed architecture and redundant networks does allow for a
sufficiently reliable transport of signalling traffic over IP. The sufficiently reliable transport of signalling traffic over IP. The
M3UA protocol is flexible enough to allow its operation and management M3UA protocol is flexible enough to allow its operation and management
in a variety of physical configurations, enabling Network Operators to in a variety of physical configurations, enabling Network Operators to
meet their performance and reliability requirements. meet their performance and reliability requirements.
To meet the stringent SS7 signalling reliability and performance To meet the stringent SS7 signalling reliability and performance
requirements for carrier grade networks, Network Operators should requirements for carrier grade networks, Network Operators SHOULD
ensure that no single point of failure is present in the end-to-end ensure that no single point of failure is present in the end-to-end
network architecture between an SS7 node and an IP-based application. network architecture between an SS7 node and an IP-based application.
This can typically be achieved through the use of redundant SGs, This can typically be achieved through the use of redundant SGs,
redundant hosts, and the provision of redundant QOS-bounded IP network redundant hosts, and the provision of redundant QOS-bounded IP network
paths for SCTP Associations between SCTP End Points. Obviously, the paths for SCTP Associations between SCTP End Points. Obviously, the
reliability of the SG, the MGC and other IP-based functional elements reliability of the SG, the MGC and other IP-based functional elements
also needs to be taken into account. The distribution of ASPs within also needs to be taken into account. The distribution of ASPs within
the available Hosts must also be considered. As an example, for a the available Hosts must also be considered. As an example, for a
particular Application Server, the related ASPs should be distributed particular Application Server, the related ASPs should be distributed
over at least two Hosts. over at least two Hosts.
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In the example above, each signalling process (SGP, ASP or IPSP) is the In the example above, each signalling process (SGP, ASP or IPSP) is the
end point to more than one SCTP association, leading to many other end point to more than one SCTP association, leading to many other
signalling processes. To support this, a signalling process must be signalling processes. To support this, a signalling process must be
able to support distribution of M3UA messages to many simultaneous able to support distribution of M3UA messages to many simultaneous
active associations. This message distribution function is based on active associations. This message distribution function is based on
the status of provisioned routing keys, the availability of signalling the status of provisioned routing keys, the availability of signalling
points in the SS7 network, and the redundancy model (active-standby, points in the SS7 network, and the redundancy model (active-standby,
load-sharing, n+k) of the remote signalling processes. load-sharing, n+k) of the remote signalling processes.
For carrier grade networks, Operators should ensure that under failure For carrier grade networks, the failure or isolation of a particular
or isolation of a particular signalling process, stable calls or signalling process SHOULD NOT cause stable calls or transactions to be
transactions are not lost. This implies that signalling processes lost. This implies that signalling processes need, in some cases, to
need, in some cases, to share the call or transaction state information share the call/transaction state or be able to pass the call state
with other signalling processes. In the case of ASPs performing call information between each other. In the case of ASPs performing call
processing, coordination may also be required with the related Media processing, coordination may also be required with the related Media
Gateway to transfer the MGC control for a particular trunk termination. Gateway to transfer the MGC control for a particular trunk termination.
However, this sharing or communication is outside the scope of this However, this sharing or communication of call/transaction state
document. information is outside the scope of this document.
This model serves as an example. M3UA imposes no restrictions as to This model serves as an example. M3UA imposes no restrictions as to
the exact layout of the network elements, the message distribution the exact layout of the network elements, the message distribution
algorithms and the distribution of the signalling processes. Instead, algorithms and the distribution of the signalling processes. Instead,
it provides a framework and a set of messages that allow for a flexible it provides a framework and a set of messages that allow for a flexible
and scalable signalling network architecture, aiming to provide and scalable signalling network architecture, aiming to provide
reliability and performance. reliability and performance.
1.4 Functional Areas 1.4 Functional Areas
1.4.1 Signalling Point Code Representation 1.4.1 Signalling Point Code Representation
Within an SS7 network, a Signalling Gateway is charged with Within an SS7 network, a Signalling Gateway is charged with
representing a set of nodes in the IP domain into the SS7 network for representing a set of nodes in the IP domain into the SS7 network for
routing purposes. The SG itself, as a physical node in the SS7 routing purposes. The SG itself, as a physical node in the SS7
network, must be addressable with an SS7 Point Code for MTP3 Management network, must be addressable with an SS7 Point Code for MTP3 Management
purposes. The SG Point Code may also be used for addressing any local purposes. The SG Point Code is also used for addressing any local MTP3-
MTP3-Users at the SG such as an SG-resident SCCP function. Users at the SG such as an SG-resident SCCP function.
An SG may be logically partitioned to operate in multiple SS7 network An SG may be logically partitioned to operate in multiple SS7 network
Appearances. In such a case, the SG must be addressable with a Point Appearances. In such a case, the SG must be addressable with a Point
Code in each network appearance, and represents a set of nodes in the Code in each network appearance, and represents a set of nodes in the
IP domain into each SS7 network. Alias PCs may also be used within an IP domain into each SS7 network. Alias Point Codes [15] may also be
SG network appearance. used within an SG network appearance.
The M3UA places no restrictions on the SS7 Point Code representation of The M3UA places no restrictions on the SS7 Point Code representation of
an AS. Application Servers can be represented under the same PC of the an AS. Application Servers can be represented under the same Point
SG, their own individual Point Codes or grouped with other applications Code of the SG, their own individual Point Codes or grouped with other
for Point Code preservation purposes. A single Point Code may be used Application Servers for Point Code preservation purposes. A single
to represent the SG and all the ASPs together, if desired. Point Code may be used to represent the SG and all the Application
Servers together, if desired.
Where Application Servers are grouped under a Point Code address, an Where Application Servers are grouped under a Point Code address, an
SPMC will include more than one AS. If full advantage of SS7 management SPMC will include more than one AS. If full advantage of SS7 management
procedures is to be taken (as is advisable in carrier grade networks) procedures is to be taken (as is advisable in carrier grade networks)
care must be taken that, if (the connection to) one AS of an SPMC care must be taken that, if one AS of an SPMC becomes unavailable, all
fails, all AS of the SPMC fail or become unreachable from the SG. If Application Servers of the SPMC become unavailable from the SG.
this is not the case, usage of SS7 transfer prohibited procedures by Otherwise, usage of SS7 transfer prohibited procedures by the SG
the SG becomes problematic as either traffic to the failed AS cannot be becomes problematic as either traffic to the unavailable AS cannot be
stopped/diverted or traffic to a still available AS will unnecessarily stopped/diverted or traffic to a still available AS will be
be stopped/diverted. (Depending on the network configuration it may unnecessarily stopped/diverted. (Depending on the network configuration
even be necessary to assign an individual SS7 point code to each AS.)
Observing these principles is of particular importance if alternative it may even be necessary to assign an individual SS7 point code to each
AS.)
Observing this principle is of particular importance if alternative
routing possibilities exist on the SS7 level (e.g. via mated SGs) or routing possibilities exist on the SS7 level (e.g. via mated SGs) or
application level (e.g. via another MGC/MG). application level (e.g. via another MGC/MG).
If an ASP or group of ASPs is available to the SS7 network via more If an ASP or group of ASPs is available to the SS7 network via more
than one SG, each with its own Point Code, the ASP(s) should be than one SG, each with its own Point Code, the ASP(s) should be
represented by a Point Code that is separate from any SG Point Code. represented by a Point Code that is separate from any SG Point Code.
This allows these SGs to be viewed from the SS7 network as "STPs", each This allows these SGs to be viewed from the SS7 network as "STPs", each
having an ongoing "route" to the same ASP(s). Under failure having an ongoing "route" to the same ASP(s). Under failure
conditions where the ASP(s) become(s) unavailable from one of the SGs, conditions where the ASP(s) become(s) unavailable from one of the SGs,
this approach enables MTP3 route management messaging between the SG this approach enables MTP3 route management messaging between the SG
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SG SG
+-------+ +---------------+ +-------+ +---------------+
| SEP +--------------| SS7 Ntwk |M3UA| ---- | SEP +--------------| SS7 Ntwk |M3UA| ----
+-------+ SS7 links | "A" | | / \ +-------+ SS7 links | "A" | | / \
|__________| +-----------+ ASPs | |__________| +-----------+ ASPs |
| | | \ / | | | \ /
+-------+ | SS7 Ntwk | | ---- +-------+ | SS7 Ntwk | | ----
| SEP +--------------+ "B" | | | SEP +--------------+ "B" | |
+-------+ +---------------+ +-------+ +---------------+
1.4.2 Message Distribution 1.4.2 Routing Contexts and Routing Keys
1.4.2.1 Address Translation and Mapping at the SG 1.4.2.1 Overview
The distribution of SS7 messages between the SG and the Application
Servers is determined by the Routing Keys and their associated Routing
Contexts. A Routing Key is essentially a set of SS7 parameters used to
filter SS7 messages, whereas the Routing Context parameter is a 4-byte
value (integer) that is associated to that Routing Key in a 1:1
relationship. The Routing Context therefore can be viewed as an index
into a sending node's Message Distribution Table containing the Routing
Key entries.
Possible SS7 address/routing information that comprise a Routing Key
entry includes, for example, the OPC, DPC, SIO found in the MTP3
routing label, or other MTP3-User specific fields such as the ISUP CIC,
SCCP subsystem number, or TCAP transaction ID. Some example Routing
Keys are: the DPC alone, the DPC/OPC combination, the DPC/OPC/CIC
combination, or the DPC/SSN combination. The particular information
used to define an M3UA Routing Key is application and network
dependent, and none of the above examples are mandated.
An Application Server Process may be configured to process signalling
traffic related to more than one Application Server, over a single SCTP
Association. In ASP Active and Inactive management messages, the
signalling traffic to be started or stopped is discriminated by the
Routing Context parameter. At an ASP, the Routing Context parameter
uniquely identifies the range of signalling traffic associated with
each Application Server that the ASP is
configured to receive.
1.4.2.2 Routing Key Limitiations
>From an SS7 network perspective, a Routing Key is limited to within a
single SS7 Destination Point Code. This is important, as the SG must be
able to present this point code to the SS7 network, without
compromising the integrity of the Signaling Point Management Cluster.
Some SS7 networks may require the SG to generate UPU messages in
failure conditions. In this case, the AS and SG may optionally limit a
Routing Key to a single Service Indicator (ISUP, TUP, SCCP, etc.). The
SG generation of a UPU message into the SS7 network is implementation
dependent, therefore no specific procedures are outlined in this
document.
Routing Keys MUST be unique in the sense that a received SS7 signalling
message cannot be matched to more than one Routing Key. It is not
necessary for the parameter range values within a particular Routing
Key to be contiguous. For example, an AS could be configured to
support call processing for multiple ranges of PSTN trunks that are not
represented by contiguous CIC values.
1.4.2.3 Managing Routing Contexts and Routing Keys
There are two ways to ways to provision a Routing Key at an SG. A
Routing Key may be configured using an implementation dependent
management interface, statically or dynamically in full accordance to
the M3UA specifications. A Routing Key may also be configured using the
M3UA dynamic registration/deregistration procedures defined in this
document. An M3UA element must implement at least one method of
Routing Key provisioning.
When using a management interface to configure Routing Keys, the
message distribution function within the SG is not limited to the set
of parameters defined in this document. Other implementation dependent
distribution algorithms may be used.
1.4.2.4 Message Distribution the SG
In order to direct messages received from the SS7 MTP3 network to the In order to direct messages received from the SS7 MTP3 network to the
appropriate IP destination, the SG must perform address translation and appropriate IP destination, the SG must perform a message distribution
mapping functions using information from the received MTP3-User function using information from the received MTP3-User message.
message.
To support this message distribution, the SG must maintain the To support this message distribution, the SG must maintain the
equivalent of a network address translation table, mapping incoming SS7 equivalent of a network address translation table, mapping incoming SS7
message information to an Application Server for a particular message information to an Application Server for a particular
application and range of traffic. This is accomplished by comparing application and range of traffic. This is accomplished by comparing
elements of the incoming SS7 message to provisioned Routing Keys in the elements of the incoming SS7 message to provisioned Routing Keys in the
SG. These Routing Keys in turn make reference to an Application Server SG. These Routing Keys in turn make reference to an Application Server
that is enabled by one or more ASP. These ASPs provide dynamic status that is enabled by one or more ASPs. These ASPs provide dynamic status
information to the SG using various management messages defined in the information on their availability, traffic handling capability and
M3UA protocol. Possible SS7 address/routing information that comprise congestion to the SG using various management messages defined in the
a Routing Key entry includes, for example, the OPC, DPC, SIO found in M3UA protocol.
the MTP3 routing label, or other MTP3-User specific fields such as the
ISUP CIC, SCCP subsystem number, or TCAP transaction ID. Some example
routing keys are: the DPC alone, the DPC/OPC combination, the
DPC/OPC/CIC combination, or the DPC/SSN combination. The particular
information used to define an M3UA Routing Key is application and
network dependent, and none of the above examples are mandated.
An Application Server contains a list of one or more ASPs that are The list of ASPs in an AS is assumed to be dynamic, taking into account
capable of processing the traffic. This list is assumed to be dynamic, the availability, traffic handling capability and congestion status of
taking into account the availability status of the individual ASPs in the individual ASPs in the list, as well as configuration changes and
the list, configuration changes, and possible fail-over mechanisms. The possible fail-over mechanisms.
M3UA protocol includes messages to convey the availability status of
the individual ASPs as input to a fail-over mechanism.
Normally, one or more ASPs is active in the ASP (i.e., currently Normally, one or more ASPs are active in the AS (i.e., currently
processing traffic) but in certain failure and transition cases it is processing traffic) but in certain failure and transition cases it is
possible that there may not be an active ASP available. Both load- possible that there may be active ASP available. Both load-sharing and
sharing and backup scenarios are supported. backup scenarios are supported.
When there is no Routing Key match for an incoming SS7 message, a When there is no Routing Key match, or only a partial match, for an
default treatment must be specified. Possible solutions are to provide incoming SS7 message, a default treatment MUST be specified. Possible
a default Application Server at the SG that directs all unallocated solutions are to provide a default Application Server at the SG that
traffic to a (set of) default ASP(s), or to drop the messages and directs all unallocated traffic to a (set of) default ASP(s), or to
provide a notification to management. The treatment of unallocated drop the message and provide a notification to management. The
traffic is implementation dependent. treatment of unallocated traffic is implementation dependent.
1.4.2.2 Address Translation and Mapping at the ASP 1.4.2.5 Message Distribution at the ASP
In order to direct messages to the SS7 network, the ASP must also In order to direct messages to the SS7 network, the ASP must also
perform an address translation and mapping function in order to choose perform a message distribution function in order to choose the proper
the proper SG or SGP for a given message. This is accomplished by SG or SGP for a given message. This is accomplished by observing the
observing the Destination Point Code and other elements of the outgoing Destination Point Code (and possibly other elements of the outgoing
message such as the SLS value), together with the SS7 destination
message, SS7 network status, SG and SGP availability, and network availability/restricted/congestion status via the SG(s) and the
appearance configuration tables. availability of the SG and SGPs themselves.
A remote Signalling Gateway may be composed of one or more SGPs that A remote Signalling Gateway may be composed of one or more SGPs that
are capable of routing SS7 traffic. As is the case with ASPs, a are capable of routing SS7 traffic. As is the case with ASPs, a
dynamic list of SGPs in an SG can be maintained, taking into account dynamic list of SGPs in an SG can be maintained, taking into account
the availability status of the individual SGPs, configuration changes the availability status of the individual SGPs, configuration changes
and fail-over mechanisms. There is, however, no M3UA messaging to and fail-over mechanisms. There is, however, no M3UA messaging to
manage the status of an SGP. Whenever an SCTP association to an SGP manage the status of an SGP. Whenever an SCTP association to an SGP
exists, it is assumed to be available. Also, every SGP of one SG exists, it is assumed to be available. Also, every SGP of one SG
communicating with one ASP regarding one AS provides identical SS7 communicating with one ASP regarding one AS provides identical SS7
connectivity to this ASP. connectivity to this ASP.
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In the case of SS7 and M3UA inter-working, the M3UA adaptation layer is In the case of SS7 and M3UA inter-working, the M3UA adaptation layer is
designed to provide an extension of the MTP3 defined user primitives. designed to provide an extension of the MTP3 defined user primitives.
1.4.3.1 Signalling Gateway SS7 Layers 1.4.3.1 Signalling Gateway SS7 Layers
The SG is responsible for terminating MTP Level 3 of the SS7 protocol, The SG is responsible for terminating MTP Level 3 of the SS7 protocol,
and offering an IP-based extension to its users. and offering an IP-based extension to its users.
>From an SS7 perspective, it is expected that the Signalling Gateway >From an SS7 perspective, it is expected that the Signalling Gateway
(SG) transmits and receives SS7 Message Signalling Units (MSUs) to and (SG) transmits and receives SS7 Message Signalling Units (MSUs) to and
from from the PSTN over a standard SS7 network interface, using the SS7
the PSTN over a standard SS7 network interface, using the SS7 Message Message Transfer Part (MTP) [14,15,16] to provide reliable transport of
Transfer Part (MTP) [14,15,16] to provide reliable transport of the the messages.
messages.
As a standard SS7 network interface, the use of MTP Level 2 signalling As a standard SS7 network interface, the use of MTP Level 2 signalling
links is not the only possibility. ATM-based High Speed Links can also links is not the only possibility. ATM-based High Speed Links can also
be used with the services of the Signalling ATM Adaptation Layer (SAAL) be used with the services of the Signalling ATM Adaptation Layer (SAAL)
[17,18]. It is possible for IP-based links to be present, using the [17,18]. It is possible for IP-based links to be present, using the
services of the MTP2-User Adaptation Layer (M2UA) [19]. These SS7 services of the MTP2-User Adaptation Layer (M2UA) [19]. These SS7
datalinks may be terminated at a Signalling Transfer Point (STP) or at datalinks may be terminated at a Signalling Transfer Point (STP) or at
a Signalling End Point (SEP). Using the services of MTP3, the SG may a Signalling End Point (SEP). Using the services of MTP3, the SG may
be capable of communicating with remote SS7 SEPs in a quasi-associated be capable of communicating with remote SS7 SEPs in a quasi-associated
fashion, where STPs may be present in the SS7 path between the SEP and fashion, where STPs may be present in the SS7 path between the SEP and
the SG. the SG.
Where ATM-based High Speed Links are used in the SS7 network, it is Where ATM-based High Speed Links are used in the SS7 network, it is
possible for the SG to use the services of the MTP-3b [20] for reliable possible for the SG to use the services of the MTP-3b [20] for reliable
transport to and from an SS7 SEP or STP. The maximum Service Data Unit
(SDU) supported by the MTP-3b is 4096 octets compared to the 272-octet transport to and from an SS7 SEP or STP. The maximum SIF length
supported by the MTP-3b is 4095 octets compared to the 272-octet
maximum of the MTP3. However, for MTP3-Users to take advantage of the maximum of the MTP3. However, for MTP3-Users to take advantage of the
larger SDU between MTP3-User peers, network architects should ensure larger SDU between MTP3-User peers, network architects should ensure
that MTP3-b is used end-to-end between the SG and the SS7-resident that MTP3-b is used end-to-end between the SG and the SS7-resident
peer. peer.
1.4.3.2 SS7 and M3UA Inter-Working at the SG 1.4.3.2 SS7 and M3UA Inter-Working at the SG
The SG provides a functional inter-working of transport functions The SG provides a functional inter-working of transport functions
between the SS7 network and the IP network by also supporting the M3UA between the SS7 network and the IP network by also supporting the M3UA
adaptation layer. It allows the transfer of MTP3-User signalling adaptation layer. It allows the transfer of MTP3-User signalling
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this, the MTP-PAUSE, MTP-RESUME and MTP-STATUS indication primitives this, the MTP-PAUSE, MTP-RESUME and MTP-STATUS indication primitives
received at the MTP3 upper layer interface at the SG need to be received at the MTP3 upper layer interface at the SG need to be
propagated to the remote MTP3-User lower layer interface at the ASP. propagated to the remote MTP3-User lower layer interface at the ASP.
(These indication primitives are, of course, also made available to any (These indication primitives are, of course, also made available to any
existing local MTP3-Users at the SG, if present.) existing local MTP3-Users at the SG, if present.)
It is important to clarify that MTP3 management messages such as TFPs It is important to clarify that MTP3 management messages such as TFPs
or TFAs received from the SS7 network are not "encapsulated" and sent or TFAs received from the SS7 network are not "encapsulated" and sent
blindly to the ASPs. Rather, the existing MTP3 management procedures blindly to the ASPs. Rather, the existing MTP3 management procedures
are followed within the MTP3 function of the SG to re-calculate the are followed within the MTP3 function of the SG to re-calculate the
MTP3 route set status and initiate any required signalling-route-set- MTP3 route set status and to initiate any required signalling-route-
test procedures into the SS7 network. Only when an SS7 destination set-test procedures into the SS7 network. Only when an SS7 destination
status changes are MTP-PAUSE or MTP-RESUME primitives invoked. These status changes are MTP-PAUSE or MTP-RESUME primitives invoked. These
primitives can also be invoked due to local SS7 link set conditions as primitives can also be invoked due to local SS7 link set conditions as
per existing MTP3 procedures. per existing MTP3 procedures.
In case where the MTP in the SG undergoes an MTP restart, event In the case where the MTP in the SG undergoes an MTP restart, event
communication to the concerned ASPs should be handled as follows: communication to the concerned ASPs should be handled as follows:
When the SG discovers SS7 network isolation, the SG sends an indication When the SG discovers SS7 network isolation, the SG sends an indication
to all concerned available ASPs (i.e., ASPs in the "active" or to all concerned available ASPs (i.e., ASPs in the "active" or
"inactive" state), using a DUNA message. For the purposes of MTP "inactive" state), using a DUNA message. For the purposes of MTP
Restart, all SPMCs with point codes different from that of the SG with Restart, all SPMCs with point codes different from that of the SG with
at least one ASP that is active or has sent an ASPAC message to the SG at least one ASP that is active or that has sent an ASPAC message to
during the first part of the restart procedure should be considered as the SG during the first part of the restart procedure should be
available. If the M3UA at the SG receives any ASPAC messages during considered as available. If the M3UA at the SG receives any ASPAC
the restart procedure, it delays the ASPAC-ACK messages until the end messages during the restart procedure, it delays the ASPAC-ACK messages
of the restart procedure. During the second part of the restart until the end of the restart procedure. During the second part of the
procedure the M3UA at the SG informs all concerned ASPs in the "active" restart procedure the M3UA at the SG informs all concerned ASPs in the
or "inactive" state of any unavailable SS7 destinations. At the end of "active" or "inactive" state of any unavailable SS7 destinations. At
the restart procedure the M3UA sends an ASPAC-ACK message to all ASPs the end of the restart procedure the M3UA sends an ASPAC-ACK message to
in the "active" state. all ASPs in the "active" state.
1.4.3.2 Application Server 1.4.3.3 Application Server
A cluster of application servers is responsible for providing the A cluster of application servers is responsible for providing the
overall support for one or more SS7 upper layers. From an SS7 overall support for one or more SS7 upper layers. From an SS7
standpoint, a Signalling Point Management Cluster (SPMC) provides standpoint, a Signalling Point Management Cluster (SPMC) provides
complete support for the upper layer service for a given point code. complete support for the upper layer service for a given point code.
As an example, an SPMC providing MGC capabilities must provide complete As an example, an SPMC providing MGC capabilities must provide complete
support for ISUP for a given point code, according to the local SS7 support for ISUP (and any other MTP3 user located at the point code of
network specifications. the SPMC) for a given point code, according to the local SS7 network
specifications.
This measure is necessary to allow the SG to accurately represent the This measure is necessary to allow the SG to accurately represent the
signalling point on the local SS7 network. signalling point on the local SS7 network.
In the case where an ASP is connected to more than one SG, the M3UA In the case where an ASP is connected to more than one SG, the M3UA
must maintain the status of configured SS7 destinations and route must maintain the status of configured SS7 destinations and route
messages according to availability/congestion status of the routes to messages according to availability/congestion/restricted status of the
these destinations. routes to these destinations.
When an ASP enters the "Inactive" state towards an SG the M3UA must When an ASP enters the "Inactive" state towards an SG the M3UA must
mark all SS7 destinations configured to be reachable via this SG as mark all SS7 destinations configured to be reachable via this SG as
available. available.
When the M3UA at an ASP receives a DUNA message indicating SS7 network When the M3UA at an ASP receives a DUNA message indicating SS7 network
isolation at an SG, it will stop any affected traffic via this SG and isolation at an SG, it will stop any affected traffic via this SG and
clear any unavailability state of SS7 destinations via this SG. When clear any unavailability state of SS7 destinations via this SG. When
the M3UA subsequently receives any DUNA messages from an SG it will the M3UA subsequently receives any DUNA messages from an SG it will
mark the effected SS7 destinations as unavailable via that SG. When mark the effected SS7 destinations as unavailable via that SG. When
the M3UA receives an ASPAC-ACK message it can resume traffic to the M3UA receives an ASPAC-ACK message it can resume traffic to
available SS7 destinations via this SG, provided the ASP is in the available SS7 destinations via this SG, provided the ASP is in the
active state towards this SG. active state towards this SG.
1.4.3.3 IPSP 1.4.3.3 IPSP Considerations
Since IPSPs use M3UA in a point-to-point fashion, there is no concept Since IPSPs use M3UA in a point-to-point fashion, there is no concept
of routing of messages beyond the remote end. Therefore, SS7 and M3UA of routing of messages beyond the remote end. Therefore, SS7 and M3UA
inter-working is not necessary for this model. inter-working is not necessary for this model.
1.4.4 Redundancy Models 1.4.4 Redundancy Models
The network address translation and mapping function of the M3UA layer The network address translation and mapping function of the M3UA layer
supports signalling process fail-over functions in order to support a supports signalling process fail-over functions in order to support a
high availability of call and transaction processing capability. high availability of call and transaction processing capability.
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"k" ASPs are available to take over for a failed or unavailable ASP. A "k" ASPs are available to take over for a failed or unavailable ASP. A
"1+1" active/standby redundancy is a subset of this model. A simplex "1+1" active/standby redundancy is a subset of this model. A simplex
"1+0" model is also supported as a subset, with no ASP redundancy. "1+0" model is also supported as a subset, with no ASP redundancy.
At the SG, an Application Server list contains active and inactive ASPs At the SG, an Application Server list contains active and inactive ASPs
to support ASP load-sharing and fail-over procedures. The list of ASPs to support ASP load-sharing and fail-over procedures. The list of ASPs
within a logical Application Server is kept updated in the SG to within a logical Application Server is kept updated in the SG to
reflect the active Application Server Process(es). reflect the active Application Server Process(es).
To avoid a single point of failure, it is recommended that a minimum of To avoid a single point of failure, it is recommended that a minimum of
two ASPs be in the list, resident in separate hosts, and therefore two ASPs be in the list, resident in separate hosts and therefore
available over different SCTP Associations. For example, in the available over different SCTP Associations. For example, in the
network shown in Figure 1, all messages to DPC x could be sent to ASP1 network shown in Figure 1, all messages to DPC x could be sent to ASP1
in Host1 or ASP1 in Host2. The AS list at SG1 might look like this: in Host1 or ASP1 in Host2. The AS list at SG1 might look like the
following:
Routing Key {DPC=x) - "Application Server #1" Routing Key {DPC=x) - "Application Server #1"
ASP1/Host1 - State=Up, Active ASP1/Host1 - State=Up, Active
ASP1/Host2 - State=Up, Inactive ASP1/Host2 - State=Up, Inactive
In this "1+1" redundancy case, ASP1 in Host1 would be sent any incoming In this "1+1" redundancy case, ASP1 in Host1 would be sent any incoming
message with DPC=x. ASP1 in Host2 would normally be brought to the message with DPC=x. ASP1 in Host2 would normally be brought to the
active state upon failure of, or loss of connectivity to, ASP1/Host1. active state upon failure of, or loss of connectivity to, ASP1/Host1.
In this example, both ASPs are Up, meaning that the related SCTP In this example, both ASPs are Up, meaning that the related SCTP
association and far-end M3UA peer is ready. association and far-end M3UA peer is ready.
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For example the two ASPs could together form a database, where incoming For example the two ASPs could together form a database, where incoming
queries may be sent to any active ASP. queries may be sent to any active ASP.
Care must be exercised by a Network Operator in the selection of the Care must be exercised by a Network Operator in the selection of the
routing information to be used as the Routing Key for a particular AS. routing information to be used as the Routing Key for a particular AS.
For example, where Application Servers are defined using ranges of ISUP For example, where Application Servers are defined using ranges of ISUP
CIC values, the Operator is implicitly splitting up control of the CIC values, the Operator is implicitly splitting up control of the
related circuit groups. Some CIC value range assignments may interfere related circuit groups. Some CIC value range assignments may interfere
with ISUP circuit group management procedures. with ISUP circuit group management procedures.
In the process of fail-over or fail-back, it is recommended that in the In the process of fail-over, it is recommended that in the case of ASPs
case of ASPs supporting call processing, stable calls do not fail. It supporting call processing, stable calls do not fail. It is possible
is possible that calls in "transition" may fail, although measures of that calls in "transition" MAY fail, although measures of communication
communication between the ASPs involved can be used to mitigate this. between the ASPs involved can be used to mitigate this. For example,
For example, the two ASPs may share call state via shared memory, or the two ASPs MAY share call state via shared memory, or MAY use an ASP
may use an ASP to ASP protocol to pass call state information. to ASP protocol to pass call state information. Any ASP-to-ASP
protocol is outside the scope of this document.
1.4.4.2 Signalling Gateway Redundancy 1.4.4.2 Signalling Gateway Redundancy
Signalling Gateways may also be distributed over multiple hosts. Much Signalling Gateways MAY also be distributed over multiple hosts. Much
like the AS model, SGs may be comprised of one or more SG Processes like the AS model, SGs may be comprised of one or more SG Processes
(SGPs), distributed over one or more hosts, using an active/standby or (SGPs), distributed over one or more hosts, using an active/standby or
a load-sharing model. An SGP is viewed as a remote SCTP end-point from a load-sharing model. An SGP is viewed as a remote SCTP end-point from
an ASP perspective. There is, however, no M3UA protocol to manage the an ASP perspective. There is, however, no M3UA protocol to manage the
status of an SGP. Whenever an SCTP association to an SGP exists, the status of an SGP. Whenever an SCTP association to an SGP exists, the
SGP is assumed to be available. Also, every SGP within an SG SGP is assumed to be available. Also, every SGP within an SG
communicating with an ASP provides identical SS7 connectivity to this communicating with an ASP provides identical SS7 connectivity to this
ASP. Should an SGP lose all or partial SS7 connectivity and other SGPs ASP. Should an SGP lose all or partial SS7 connectivity and other SGPs
exist, the SGP must terminate the SCTP associations to the concerned exist, the SGP must terminate the SCTP associations to the concerned
ASPs. ASPs.
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multiple SGPs. multiple SGPs.
It may also be possible for an ASP to use more than one SG to access a It may also be possible for an ASP to use more than one SG to access a
specific SS7 end point, in a model that resembles an SS7 STP mated specific SS7 end point, in a model that resembles an SS7 STP mated
pair. Typically, SS7 STPs are deployed in mated pairs, with traffic pair. Typically, SS7 STPs are deployed in mated pairs, with traffic
load-shared between them. Other models are also possible, subject to load-shared between them. Other models are also possible, subject to
the limitations of the local SS7 network provisioning guidelines. the limitations of the local SS7 network provisioning guidelines.
>From the perspective of the M3UA at an ASP, a particular SG is capable >From the perspective of the M3UA at an ASP, a particular SG is capable
of transferring traffic to an SS7 destination if an SCTP association of transferring traffic to an SS7 destination if an SCTP association
with at least one SGP of the SG is established, the SGP has received an with at least one SGP of the SG is established, the SGP has returned an
indication from the ASP M3UA that the ASP is actively handling traffic ASPAC Ack message acknowledging to the ASP M3UA that the ASP is
for that destination, and the SG has not indicated that the destination actively handling traffic for that destination, and the SG has not
is inaccessible. When an ASP is configured to use multiple SGs for indicated that the destination is inaccessible. When an ASP is
transferring traffic to the SS7 network, the ASP must maintain configured to use multiple SGs for transferring traffic to the SS7
knowledge of the current capability of the SGs to handle traffic to network, the ASP must maintain knowledge of the current capability of
destinations of interest. This information is crucial to the overall the SGs to handle traffic to destinations of interest. This
reliability of the service, for both active/standby and load-sharing information is crucial to the overall reliability of the service, for
model, in the event of failures, recovery and maintenance activities. both active/standby and load-sharing model, in the event of failures,
The ASP M3UA may also use this information for congestion avoidance recovery and maintenance activities. The ASP M3UA may also use this
purposes. information for congestion avoidance purposes. The distribution of the
MTP3-user messages over the SGs should be done in such a way to
minimize message mis-sequencing, as required by the SS7 User Parts.
1.4.5 Flow Control 1.4.5 Flow Control
Local Management at an ASP may wish to stop traffic across an SCTP Local Management at an ASP may wish to stop traffic across an SCTP
association in order to temporarily remove the association from service association in order to temporarily remove the association from service
or to perform testing and maintenance activity. The function could or to perform testing and maintenance activity. The function could
optionally be used to control the start of traffic on to a newly optionally be used to control the start of traffic on to a newly
available SCTP association. available SCTP association.
1.4.6 Congestion Management 1.4.6 Congestion Management
The M3UA Layer is informed of local and IP network congestion by means The M3UA Layer is informed of local and IP network congestion by means
of an implementation-dependent function (e.g., an implementation- of an implementation-dependent function (e.g., an implementation-
dependent indication from the SCTP of IP network congestion). When an dependent indication from the SCTP of IP network congestion).
SG determines that the transport of SS7 messages to a Signalling Point
Management Cluster (SPMC) is encountering congestion, the SG should
trigger SS7 MTP3 Transfer Controlled management messages to originating
SS7 nodes. The triggering of SS7 MTP3 Management messages from an SG is
an implementation-dependent function.
At an ASP, congestion is indicated to local MTP3-Users by means of an At an ASP or IPSP, the M3UA indicates congestion to local MTP3-Users by
MTP-Status primitive indicating congestion, to invoke appropriate upper means of an MTP-Status primitive, as per current MTP3 procedures, to
layer responses, as per current MTP3 procedures. invoke appropriate upper layer responses.
The M3UA should indicate local ASP congestion to the SG with an SCON When an SG determines that the transport of SS7 messages to a
message. When an SG receives an SCON message from an ASP it should Signalling Point Management Cluster (SPMC) is encountering congestion,
the SG should trigger SS7 MTP3 Transfer Controlled management messages
to originating SS7 nodes, as per current MTP3 procedures. The
triggering of SS7 MTP3 Management messages from an SG is an
implementation-dependent function.
trigger SS7 MTP3 Transfer Controlled management messages to concerned The M3UA at an ASP or IPSP should indicate local congestion to an M3UA
SS7 destinations according to established MTP procedures. peer with an SCON message. When an SG M3UA receives an SCON message
from an ASP, and the SG determines that an SPMC is now encountering
congestion, it should trigger SS7 MTP3 Transfer Controlled management
messages to concerned SS7 destinations according to current MTP
procedures.
1.4.7 SCTP Stream Mapping. 1.4.7 SCTP Stream Mapping.
The M3UA at both the SG and ASP also supports the assignment of The M3UA at both the SG and ASP also supports the assignment of
signalling traffic into streams within an SCTP association. Traffic signalling traffic into streams within an SCTP association. Traffic
that requires sequencing must be assigned to the same stream. To that requires sequencing must be assigned to the same stream. To
accomplish this, MTP3-User traffic may be assigned to individual accomplish this, MTP3-User traffic may be assigned to individual
streams based on, for example, the SLS value in the MTP3 Routing Label streams based on, for example, the SLS value in the MTP3 Routing Label
or the ISUP CIC assignment, subject of course to the maximum number of or the ISUP CIC assignment, subject of course to the maximum number of
streams supported by the underlying SCTP association. streams supported by the underlying SCTP association.
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The use of SCTP streams within M3UA is recommended in order to minimize The use of SCTP streams within M3UA is recommended in order to minimize
transmission and buffering delays, therefore improving the overall transmission and buffering delays, therefore improving the overall
performance and reliability of the signalling elements. The performance and reliability of the signalling elements. The
distribution of the MTP3 user messages over the various streams should distribution of the MTP3 user messages over the various streams should
be done in such a way to minimize message mis-sequencing, as required be done in such a way to minimize message mis-sequencing, as required
by the SS7 User Parts. by the SS7 User Parts.
1.4.8 Client/Server Model 1.4.8 Client/Server Model
The SG takes on the role of server while the ASP is the client. ASPs The SG takes on the role of server while the ASP is the client. ASPs
must initiate the SCTP association to the SG. MUST initiate the SCTP association to the SG.
In the case of IPSP to IPSP communication, one side can be designated In the case of IPSP to IPSP communication, the peer endpoints using
as the initiator of the SCTP association and M3UA messaging. M3UA SHOULD be configured so that one always takes on the role of
client and the other the role of server for initiating SCTP
associations and M3UA messaging.
The SCTP (and UDP/TCP) Registered User Port Number Assignment for M3UA The SCTP (and UDP/TCP) Registered User Port Number Assignment for M3UA
is 2905. is 2905.
1.5 Sample Configurations 1.5 Sample Configurations
1.5.1 Example 1: ISUP message transport 1.5.1 Example 1: ISUP message transport
******** SS7 ***************** IP ******** ******** SS7 ***************** IP ********
* SEP *---------* SG *--------* ASP * * SEP *---------* SG *--------* ASP *
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messages that are destined to the MGC are received as MTP-TRANSFER messages that are destined to the MGC are received as MTP-TRANSFER
indication primitives from the MTP Level 3 upper layer interface and indication primitives from the MTP Level 3 upper layer interface and
are sent to the local M3UA-resident message distribution function for are sent to the local M3UA-resident message distribution function for
ongoing routing to the final IP destination. MTP-TRANSFER primitives ongoing routing to the final IP destination. MTP-TRANSFER primitives
received from the local M3UA network address translation and mapping received from the local M3UA network address translation and mapping
function are sent to the MTP Level 3 upper layer interface as MTP- function are sent to the MTP Level 3 upper layer interface as MTP-
TRANSFER request primitives for on-going MTP Level 3 routing to an SS7 TRANSFER request primitives for on-going MTP Level 3 routing to an SS7
SEP. For the purposes of providing SS7 network status information the SEP. For the purposes of providing SS7 network status information the
NIF also delivers MTP-PAUSE, MTP-RESUME and MTP-STATUS indication NIF also delivers MTP-PAUSE, MTP-RESUME and MTP-STATUS indication
primitives received from the MTP Level 3 upper layer interface to the primitives received from the MTP Level 3 upper layer interface to the
local M3UA-resident management function. local M3UA-resident management function. In addition, as an
implementation and network option, restricted destinations are
communicated from MTP network management to the local M3UA-resident
management function.
1.5.2 Example 2: SCCP Transport between IPSPs 1.5.2 Example 2: SCCP Transport between IPSPs
******** IP ******** ******** IP ********
* IPSP * * IPSP * * IPSP * * IPSP *
******** ******** ******** ********
+------+ +------+ +------+ +------+
|SCCP- | |SCCP- | |SCCP- | |SCCP- |
| User | | User | | User | | User |
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| IP | | IP | | IP | | IP |
+------+ +------+ +------+ +------+
|________________| |________________|
This example shows an architecture where no Signalling Gateway is used. This example shows an architecture where no Signalling Gateway is used.
In this example, SCCP messages are exchanged directly between two IP- In this example, SCCP messages are exchanged directly between two IP-
resident IPSPs with resident SCCP-User protocol instances, such as resident IPSPs with resident SCCP-User protocol instances, such as
RANAP or TCAP. SS7 network inter-working is not required, therefore RANAP or TCAP. SS7 network inter-working is not required, therefore
there is no MTP3 network management status information for the SCCP and there is no MTP3 network management status information for the SCCP and
SCCP-User protocols to consider. Any MTP-PAUSE, -RESUME or -STATUS SCCP-User protocols to consider. Any MTP-PAUSE, -RESUME or -STATUS
indications from the M3UA to the SCCP should consider only the status indications from the M3UA to the SCCP should consider the status of the
of the SCTP Association and underlying IP network. SCTP Association and underlying IP network and any congestion
information received from the remote site.
1.5.3 Example 3: SG resident SCCP layer, with remote ASP 1.5.3 Example 3: SG resident SCCP layer, with remote ASP
******** SS7 ***************** IP ******** ******** SS7 ***************** IP ********
* SEP *---------* *--------* * * SEP *---------* *--------* *
* or * * SG * * ASP * * or * * SG * * ASP *
* STP * * * * * * STP * * * * *
******** ***************** ******** ******** ***************** ********
+------+ +---------------+ +------+ +------+ +---------------+ +------+
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| L1 | | L1 | | IP | | IP | | L1 | | L1 | | IP | | IP |
+------+ +------+ +------+ +------+ +------+ +------+ +------+ +------+
|_______________| |______________| |_______________| |______________|
STP - SS7 Signalling Transfer Point STP - SS7 Signalling Transfer Point
In this example, the SG contains an instance of the SS7 SCCP protocol In this example, the SG contains an instance of the SS7 SCCP protocol
layer that may, for example, perform the SCCP Global Title Translation layer that may, for example, perform the SCCP Global Title Translation
(GTT) function for messages logically addressed to the SG SCCP. If the (GTT) function for messages logically addressed to the SG SCCP. If the
result of a GTT for an SCCP message yields an SS7 DPC or DPC/SSN result of a GTT for an SCCP message yields an SS7 DPC or DPC/SSN
address result of an SCCP peer located in the IP domain, the resulting address an SCCP peer located in the IP domain, the resulting MTP-
MTP-TRANSFER request primitive is sent to the local M3UA-resident TRANSFER request primitive is sent to the local M3UA-resident network
network address translation and mapping function for ongoing routing to address translation and mapping function for ongoing routing to the
the final IP destination. final IP destination.
Similarly, the SCCP instance in an SG can perform the SCCP GTT service Similarly, the SCCP instance in an SG can perform the SCCP GTT service
for messages logically addressed to it from SCCP peers in the IP for messages logically addressed to it from SCCP peers in the IP
domain. In this case, MTP-TRANSFER messages are sent from the local domain. In this case, MTP-TRANSFER messages are sent from the local
M3UA-resident network address translation and mapping function to the M3UA-resident network address translation and mapping function to the
SCCP for GTT. If the result of the GTT yields the address of an SCCP SCCP for GTT. If the result of the GTT yields the address of an SCCP
peer in the SS7 network then the resulting MTP-TRANSFER request is peer in the SS7 network then the resulting MTP-TRANSFER request is
given to the MTP3 for delivery to an SS7-resident node. given to the MTP3 for delivery to an SS7-resident node.
It is possible that the above SCCP GTT at the SG could yield the It is possible that the above SCCP GTT at the SG could yield the
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>From ITU Q.701 [14]: >From ITU Q.701 [14]:
MTP-TRANSFER request MTP-TRANSFER request
MTP-TRANSFER indication MTP-TRANSFER indication
MTP-PAUSE indication MTP-PAUSE indication
MTP-RESUME indication MTP-RESUME indication
MTP-STATUS indication MTP-STATUS indication
1.6.2 Definition of the boundary between M3UA and SCTP 1.6.2 Definition of the boundary between M3UA and SCTP
The upper layer primitives provided by the SCTP are provided in [13] An example of the upper layer primitives provided by the SCTP are
provided in Reference [13] Section 10.
1.6.3 Definition of the Boundary between M3UA and Layer Management 1.6.3 Definition of the Boundary between M3UA and Layer Management
M-SCTP ESTABLISH request M-SCTP ESTABLISH request
Direction: LM -> M3UA Direction: LM -> M3UA
Purpose: LM requests ASP to establish an SCTP association with an SG Purpose: LM requests ASP to establish an SCTP association with an
or IPSP. SG.
M-STCP ESTABLISH confirm M-STCP ESTABLISH confirm
Direction: M3UA -> LM Direction: M3UA -> LM
Purpose: ASP confirms to LM that it has established an SCTP Purpose: ASP confirms to LM that it has established an SCTP
association with an SG or IPSP. association with an SG.
M-SCTP ESTABLISH indication M-SCTP ESTABLISH indication
Direction: M3UA -> LM Direction: M3UA -> LM
Purpose: M3UA informs LM that a remote ASP has established an SCTP Purpose: M3UA informs LM that a remote ASP has established an SCTP
association. association.
M-SCTP RELEASE request M-SCTP RELEASE request
Direction: LM -> M3UA Direction: LM -> M3UA
Purpose: LM requests ASP to release an SCTP association with SG or Purpose: LM requests ASP to release an SCTP association with SG.
IPSP.
M-SCTP RELEASE confirm M-SCTP RELEASE confirm
Direction: M3UA -> LM Direction: M3UA -> LM
Purpose: ASP confirms to LM that it has released SCTP association Purpose: ASP confirms to LM that it has released SCTP association
with SG. with SG.
M-SCTP RELEASE indication M-SCTP RELEASE indication
Direction: M3UA -> LM Direction: M3UA -> LM
Purpose: M3UA informs LM that a remote ASP has released an SCTP Purpose: M3UA informs LM that a remote ASP has released an SCTP
Association or the SCTP association has failed. Association or the SCTP association has failed.
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Purpose: M3UA reports that it has received an ERROR message from Purpose: M3UA reports that it has received an ERROR message from
its peer or that a local operation has been unsuccessful. its peer or that a local operation has been unsuccessful.
M-ASP UP request M-ASP UP request
Direction: LM -> M3UA Direction: LM -> M3UA
Purpose: LM requests ASP to start its operation and send an ASP-UP Purpose: LM requests ASP to start its operation and send an ASP-UP
Message to its peer. Message to its peer.
M-ASP UP confirm M-ASP UP confirm
Direction: M3UA -> LM Direction: M3UA -> LM
Purpose: M3UA confirms requested ASP-UP change has been successfully Purpose: ASP reports that is has received an ASP UP Acknowledgement
acknowledged by the M3UA peer. message from the SG.
M-ASP UP indication M-ASP UP indication
Direction: M3UA -> LM Direction: M3UA -> LM
Purpose: M3UA reports it has successfully processed an incoming ASP- Purpose: M3UA reports it has successfully processed an incoming ASP-
UP request from its peer. UP request from its peer.
M-ASP DOWN request M-ASP DOWN request
Direction: LM -> M3UA Direction: LM -> M3UA
Purpose: LM requests ASP to stop its operation and send an ASP-DOWN Purpose: LM requests ASP to stop its operation and send an ASP-DOWN
Message to its peer. Message to its peer.
M-ASP DOWN confirm M-ASP DOWN confirm
Direction: M3UA -> LM Direction: M3UA -> LM
Purpose: M3UA confirms requested ASP-DOWN change has been Purpose: ASP reports that is has received an ASP DOWN
successfully acknowledged by the M3UA peer. Acknowledgement message from the SG.
M-ASP DOWN indication M-ASP DOWN indication
Direction: M3UA -> LM Direction: M3UA -> LM
Purpose: M3UA reports it has successfully processed an incoming ASP- Purpose: M3UA reports it has successfully processed an incoming ASP-
DOWN request from its peer. DOWN request from its peer.
M-ASP-ACTIVE request M-ASP-ACTIVE request
Direction: LM -> M3UA Direction: LM -> M3UA
Purpose: LM requests ASP to send an ASP-ACTIVE message to its peer Purpose: LM requests ASP to send an ASP-ACTIVE message to its peer.
and to start data transfer.
M-ASP ACTIVE confirm M-ASP ACTIVE confirm
Direction: M3UA -> LM Direction: M3UA -> LM
Purpose: LM confirms requested ASP-ACTIVE change has been Purpose: ASP reports that is has received an ASP ACTIVE
successfully acknowledged by the M3UA peer. Acknowledgement message from the SG.
M-ASP ACTIVE indication M-ASP ACTIVE indication
Direction: M3UA -> LM Direction: M3UA -> LM
Purpose: LM reports it has successfully processed an incoming ASP- Purpose: LM reports it has successfully processed an incoming ASP-
ACTIVE request from its peer. ACTIVE request from its peer.
M-ASP-INACTIVE request M-ASP-INACTIVE request
Direction: LM -> M3UA Direction: LM -> M3UA
Purpose: LM requests ASP to stop data transfer and send an ASP- Purpose: LM requests ASP to send an ASP- Inactive message to the SG.
Inactive message to the SG.
M-ASP INACTIVE confirm M-ASP INACTIVE confirm
Direction: LM -> M3UA Direction: LM -> M3UA
Purpose: LM confirms requested ASP-INACTIVE change has been Purpose: ASP reports that is has received an ASP INACTIVE
successfully acknowledged by the M3UA peer. Acknowledgement message from the SG.
M-ASP INACTIVE indication M-ASP INACTIVE indication
Direction: M3UA -> LM Direction: M3UA -> LM
Purpose: LM reports it has successfully processed an incoming ASP- Purpose: LM reports it has successfully processed an incoming ASP-
INACTIVE request from its peer. INACTIVE request from its peer.
M-AS ACTIVE indication M-AS ACTIVE indication
Direction: M3UA -> LM Direction: M3UA -> LM
Purpose: LM reports that an AS has moved to the ACTIVE state. Purpose: LM reports that an AS has moved to the ACTIVE state.
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3.0 M3UA Protocol Elements 3.0 M3UA Protocol Elements
The general M3UA message format includes a Common Message Header The general M3UA message format includes a Common Message Header
followed by zero or more parameters as defined by the Message Type. followed by zero or more parameters as defined by the Message Type.
For forward compatibility, all Message Types may have attached For forward compatibility, all Message Types may have attached
parameters even if none are specified in this version. parameters even if none are specified in this version.
3.1 Common Message Header 3.1 Common Message Header
The protocol messages for MTP3-User Adaptation require a message The protocol messages for MTP3-User Adaptation require a message header
structure that contains a version, message type, message length, and which contains the adaptation layer version, the message type, and
message contents. This message header is common among all signalling message length.
protocol adaptation layers:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Version | Reserved | Message Class | Message Type | | Version | Reserved | Message Class | Message Type |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Message Length | | Message Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
\ \ \ \
/ / / /
All fields in an M3UA message MUST be transmitted in the network byte All fields in an M3UA message MUST be transmitted in the network byte
order, unless otherwise stated. order, unless otherwise stated.
M3UA Protocol Version: 8 bits (unsigned integer) 3.1.1 M3UA Protocol Version: 8 bits (unsigned integer)
The version field contains the version of the M3UA adaptation layer. The version field contains the version of the M3UA adaptation layer.
The supported versions are:
The supported versions are the following:
1 Release 1.0 1 Release 1.0
3.1.2 Message Classes and Types
The following list contains the valid Message Classes:
Message Class: 8 bits (unsigned integer) Message Class: 8 bits (unsigned integer)
The following list contains the Message Type Classes for the defined The following list contains the valid Message Type Classes:
messages.
0 Management (MGMT) Message 0 Management (MGMT) Message [IUA/M2UA/M3UA/SUA]
1 Transfer Messages 1 Transfer Messages [M3UA]
2 SS7 Signalling Network Management (SSNM) Messages 2 SS7 Signalling Network Management (SSNM) Messages [M3UA/SUA]
3 ASP State Maintenance (ASPSM) Messages 3 ASP State Maintenance (ASPSM) Messages [IUA/M2UA/M3UA/SUA]
4 ASP Traffic Maintenance (ASPTM) Messages 4 ASP Traffic Maintenance (ASPTM) Messages [IUA/M2UA/M3UA/SUA]
5 to 255 Reserved 5 Q.921/Q.931 Boundary Primitives Transport (QPTM) Messages
[IUA]
6 MTP2 User Adaptation (MAUP) Messages [M2UA]
7 Connectionless Messages [SUA]
8 Connection-Oriented Messages [SUA]
9 Routing Key Management (RKM) Messages (M3UA)
10 to 127 Reserved by the IETF
28 to 255 Reserved for IETF-Defined Message Class extensions
Message Type: 8 bits (unsigned integer) Message Type: 8 bits (unsigned integer)
The following list contains the message types for the defined The following list contains the message types for the defined
messages. messages.
Management (MGMT) Message Management (MGMT) Message
0 Error (ERR) 0 Error (ERR)
1 Notify (NTFY) 1 Notify (NTFY)
2 to 255 Reserved for Management Messages 2 to 127 Reserved by the IETF
128 to 255 Reserved for IETF-Defined MGMT extensions
Transfer Messages Transfer Messages
0 Reserved 0 Reserved
1 Payload Data (DATA) 1 Payload Data (DATA)
2 to 255 Reserved for Transfer Messages 2 to 127 Reserved by the IETF
128 to 255 Reserved for IETF-Defined Transfer extensions
SS7 Signalling Network Management (SSNM) Messages SS7 Signalling Network Management (SSNM) Messages
0 Reserved 0 Reserved
1 Destination Unavailable (DUNA) 1 Destination Unavailable (DUNA)
2 Destination Available (DAVA) 2 Destination Available (DAVA)
3 Destination State Audit (DAUD) 3 Destination State Audit (DAUD)
4 SS7 Network Congestion State (SCON) 4 SS7 Network Congestion State (SCON)
5 Destination User Part Unavailable (DUPU) 5 Destination User Part Unavailable (DUPU)
6 to 255 Reserved for SSNM Messages 6 Destination Restricted (DRST)
7 to 127 Reserved by the IETF
128 to 255 Reserved for IETF-Defined SSNM extensions
ASP State Maintenance (ASPSM) Messages ASP State Maintenance (ASPSM) Messages
0 Reserved 0 Reserved
1 ASP Up (UP) 1 ASP Up (UP)
2 ASP Down (DOWN) 2 ASP Down (DOWN)
3 Heartbeat (BEAT) 3 Heartbeat (BEAT)
4 ASP Up Ack (UP ACK) 4 ASP Up Ack (UP ACK)
5 ASP Down Ack (DOWN ACK) 5 ASP Down Ack (DOWN ACK)
6 Heatbeat Ack (BEAT ACK) 6 Heatbeat Ack (BEAT ACK)
7 to 127 Reserved by the IETF
7 to 255 Reserved for ASPSM Messages 128 to 255 Reserved for IETF-Defined ASPSM extensions
ASP Traffic Maintenance (ASPTM) Messages ASP Traffic Maintenance (ASPTM) Messages
0 Reserved 0 Reserved
1 ASP Active (ACTIVE) 1 ASP Active (ACTIVE)
2 ASP Inactive (INACTIVE) 2 ASP Inactive (INACTIVE)
3 ASP Active Ack (ACTIVE ACK) 3 ASP Active Ack (ACTIVE ACK)
4 ASP Inactive Ack (INACTIVE ACK) 4 ASP Inactive Ack (INACTIVE ACK)
5 to 255 Reserved for ASPTM Messages 5 to 127 Reserved by the IETF
128 to 255 Reserved for IETF-Defined ASPTM extensions
Reserved: 8 bits Routing Key Management (RKM) Messages
Should be set to all '0's and ignored by the receiver. 0 Reserved
1 Registration Request (REG REQ)
2 Registration Response (REG RSP)
3 Deregistration Request (DEREG REQ)
4 Deregistration Response (DEREG RSP)
5 to 127 Reserved by the IETF
128 to 255 Reserved for IETF-Defined ASPTM extensions
Message Length: 32-bits (unsigned integer) 3.1.3 Reserved: 8 bits
The Reserved field SHOULD be set to all '0's and ignored by the
receiver.
3.1.4 Message Length: 32-bits (unsigned integer)
The Message Length defines the length of the message in octets, The Message Length defines the length of the message in octets,
including the header. including the Common Header. For messages with a final parameter
containing padding, the parameter padding MUST be included in the
Message Length.
Note: A receiver SHOULD accept the message whether or not the final
parameter padding is included in the message length.
3.2 Variable-Length Parameter Format 3.2 Variable-Length Parameter Format
M3UA messages consist of a Common Header followed by zero or more M3UA messages consist of a Common Header followed by zero or more
parameters, as defined by the message type. The variable-length variable length parameters, as defined by the message type. All the
parameters contained in a message are defined in a Tag-Length-Value parameters contained in a message are defined in a Tag-Length-Value
format as shown below. format as shown below.
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Parameter Tag | Parameter Length | | Parameter Tag | Parameter Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
\ \ \ \
/ Parameter Value / / Parameter Value /
\ \ \ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Where more than one parameter is included in a message, the parameters
may be in any order, except where explicitly mandated. A receiver
SHOULD accept the parameters in any order.
Parameter Tag: 16 bits (unsigned integer) Parameter Tag: 16 bits (unsigned integer)
Tag field is a 16-bit identifier of the type of parameter. It takes The Tag field is a 16-bit identifier of the type of parameter. It
a value of 0 to 65534. takes a value of 0 to 65534. The parameter Tags defined are as
follows:
0 Reserved
1 Network Appearance
2 Protocol Data 1
3 Protocol Data 2
4 Info String
5 Affected Destinations
6 Routing Context
7 Diagnostic Information
8 Heartbeat Data
9 User/Cause
10 Reason
11 Traffic Mode Type
12 Error Code
13 Status Type/ID
14 Congestion Indications
15 Concerned Destination
16 Routing Key
17 Registration Result
18 De-registration Result
19 Local_Routing Key Identifier
20 Destination Point Code
21 Service Indicators
22 Subsystem Numbers
23 Originating Point Code List
24 Circuit Range
25 Registration Results
26 De-Registration Results
27 to 65534 Reserved by the IETF
The value of 65535 is reserved for IETF-defined extensions. Values The value of 65535 is reserved for IETF-defined extensions. Values
other than those defined in specific parameter description are other than those defined in specific parameter description are
reserved for use by the IETF. reserved for use by the IETF.
Parameter Length: 16 bits (unsigned integer) Parameter Length: 16 bits (unsigned integer)
The Parameter Length field contains the size of the parameter in The Parameter Length field contains the size of the parameter in
bytes, including the Parameter Tag, Parameter Length, and Parameter bytes, including the Parameter Tag, Parameter Length, and Parameter
Value fields. The Parameter Length does not include any padding Value fields. The Parameter Length does not include any padding
skipping to change at page 30, line 31 skipping to change at page 33, line 42
Parameter Value: variable-length. Parameter Value: variable-length.
The Parameter Value field contains the actual information to be The Parameter Value field contains the actual information to be
transferred in the parameter. transferred in the parameter.
The total length of a parameter (including Tag, Parameter Length and The total length of a parameter (including Tag, Parameter Length and
Value fields) MUST be a multiple of 4 bytes. If the length of the Value fields) MUST be a multiple of 4 bytes. If the length of the
parameter is not a multiple of 4 bytes, the sender pads the parameter is not a multiple of 4 bytes, the sender pads the
Parameter at the end (i.e., after the Parameter Value field) with Parameter at the end (i.e., after the Parameter Value field) with
all zero bytes. The length of the padding is NOT included in the all zero bytes. The length of the padding is NOT included in the
parameter length field. A sender should NEVER pad with more than 3 parameter length field. A sender SHOULD NEVER pad with more than 3
bytes. The receiver MUST ignore the padding bytes. bytes. The receiver MUST ignore the padding bytes.
3.3 Transfer Messages 3.3 Transfer Messages
The following section describes the Transfer messages and parameter The following section describes the Transfer messages and parameter
contents. contents.
3.3.1 Payload Data Message (DATA) 3.3.1 Payload Data Message (DATA)
The Data message contains the SS7 MTP3-User protocol data, which is an The DATA message contains the SS7 MTP3-User protocol data, which is an
MTP-TRANSFER primitive, including the complete MTP3 Routing Label. The MTP-TRANSFER primitive, including the complete MTP3 Routing Label. The
Data message contains the following variable length parameters: Data message contains the following variable length parameters:
Network Appearance Optional Network Appearance Optional
Protocol Data Mandatory Protocol Data 1 or 2 Mandatory
The following format MUST be used for the Data Message: The following format MUST be used for the Data Message:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 1 | Length = 8 | | Tag = 1 | Length = 8 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Network Appearance* | | Network Appearance* |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
skipping to change at page 31, line 32 skipping to change at page 34, line 41
The optional Network Appearance parameter identifies the SS7 network The optional Network Appearance parameter identifies the SS7 network
context for the message, for the purposes of logically separating context for the message, for the purposes of logically separating
the signalling traffic between the SG and the Application Server the signalling traffic between the SG and the Application Server
Process over a common SCTP Association. An example is where an SG Process over a common SCTP Association. An example is where an SG
is logically partitioned to appear as an element in four different is logically partitioned to appear as an element in four different
national SS7 networks. national SS7 networks.
In a Data message, the Network Appearance implicitly defines the SS7 In a Data message, the Network Appearance implicitly defines the SS7
Point Code format used, the SS7 Network Indicator value, and the Point Code format used, the SS7 Network Indicator value, and the
MTP3/MTP3-User protocol type/variant/version used within the SS7 MTP3 and possibly the MTP3-User protocol type/variant/version used
network partition. Where an SG operates in the context of a single within the SS7 network partition. Where an SG operates in the
SS7 network, or individual SCTP associations are dedicated to each context of a single SS7 network, or individual SCTP associations are
SS7 network context, the Network Appearance parameter is not dedicated to each SS7 network context, the Network Appearance
required. parameter is not required.
The Network Appearance parameter value is of local significance The Network Appearance parameter value is of local significance
only, coordinated between the SG and ASP. only, coordinated between the SG and ASP. Therefore, in the case
where an ASP is connected to more than one SG, the same SS7 network
context may be identified by different Network Appearances depending
over which SG a message is being transmitted/received.
Where the optional Network Appearance parameter is present, it must Where the optional Network Appearance parameter is present, it must
be the first parameter in the message as it defines the format of be the first parameter in the message as it defines the format of
the Protocol Data field. the Protocol Data field.
Protocol Data: variable length Protocol Data 1 or 2: variable length
The Protocol Data field contains the SS7 MTP3-User application One of two possible Protocol Data parameters are included in a DATA
message: Protocol Data 1 or Protocol Data 2.
The Protocol Data 1 parameter contains the original SS7 MTP3
message, including the Service Information Octet and Routing Label. message, including the Service Information Octet and Routing Label.
The Protocol Data parameter contains the following fields:
The Protocol Data 1 parameter contains the following fields:
Service Information Octet. Includes: Service Information Octet. Includes:
Service Indicator, Service Indicator,
Network Indicator, Network Indicator,
and Spare/Priority codes and Spare/Priority codes
Routing Label. Includes: Routing Label. Includes:
Destination Point Code, Destination Point Code,
Originating Point Code, Originating Point Code,
And Signalling Link Selection Code (SLS) And Signalling Link Selection Code (SLS)
User Protocol Data. Includes MTP3-User protocol elements: User Protocol Data. Includes:
ISUP, SCCP, or TUP parameters MTP3-User protocol elements (e.g., ISUP, SCCP, or TUP
parameters)
The format is as defined in the relevant MTP standards for the SS7 The Protocol Data 2 parameter contains all the information in
protocol being transported. The format is either implicitly known Protocol Data 1 as described above, plus the MTP2 Length Indicator
or identified by the Network Appearance parameter. octet. The MTP2 Length Indicator (LI) octet appears before the SIO
and Routing Label information. The MTP2 Length Indicator octet is
required for some national MTP variants that use the spare bits in
the LI to carry additional information of interest to the MTP3 and
MTP3-User (e.g., the Japan TTC standard use of LI spare bits to
indicate message priority)
The Payload Data format is as defined in the relevant MTP standards
for the SS7 protocol being transported. The format is either
implicitly known or identified by the Network Appearance parameter.
Note: In the SS7 Recommendations, the format of the messages and
fields within the messages are based on bit transmission order. In
these recommendations the Least Significant Bit (LSB) of each field
is positioned to the right. For this document the received SS7
fields are populated octet by octet as received into the 4-octet
word as shown in the examples below.
For the ANSI protocol example, the Protocol Data field format is For the ANSI protocol example, the Protocol Data field format is
shown below: shown below:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SIO | DPC Network | DPC Cluster | DPC Member | | SIO | DPC Member | DPC Cluster | DPC Network |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OPC Network | OPC Cluster | OPC Member | SLS | | OPC Member | OPC Cluster | OPC Network | SLS |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
\ \ \ \
/ Protocol Data / / Protocol Data /
\ \ \ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|MSB---------------------------------------------------------LSB| |MSB---------------------------------------------------------LSB|
Within each octet the Least Significant Bit (LSB) per the SS7
Recommendations is to the right (e.g., bit 7 of SIO is the LSB).
For the ITU international protocol example, the Protocol Data field For the ITU international protocol example, the Protocol Data field
is shown below. is shown below.
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SIO | DPC | DPC | DPC | OPC | OPC | | SIO | DPC | DPC |OPC| DPC | DPC | OPC |@|
| |Zone | Region | SP |Zone | Region | | | Region *| SP *|SP*|Zone*| reg.| Region *| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|*| OPC | SLS | | | SLS | OPC |$| Protocol |
|*| SP | | | | *| SP *| | Data |
+-+-+-+-+-+-+-+-+ +
\ \
/ Protocol Data /
\ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|MSB---------------------------------------------------------LSB| * marks LSB of each field; @ = OPC SP MSB; $ = OPC region MSB
* LSB of OPC Region
3.4 SS7 Signalling Network Management (SSNM) Messages 3.4 SS7 Signalling Network Management (SSNM) Messages
3.4.1 Destination Unavailable (DUNA) 3.4.1 Destination Unavailable (DUNA)
The DUNA message is sent from the SG to all concerned ASPs to indicate The DUNA message is sent from the SG to all concerned ASPs to indicate
that the SG has determined that one or more SS7 destinations are that the SG has determined that one or more SS7 destinations are
unreachable. It is also sent in response to a message from the ASP to unreachable. It is also sent in response to a message from the ASP to
an unreachable SS7 destination. The MTP3-User at the ASP is expected an unreachable SS7 destination. As an implementation option the SG may
to stop traffic to the affected destination through the SG initiating suppress the sending of subsequent "response" DUNAs regarding a certain
the DUNA as per the defined MTP3-User procedures. unreachable SS7 destination for a certain period in order to give the
remote side time to react. The MTP3-User at the ASP is expected to stop
traffic to the affected destination through the SG initiating the DUNA
as per the defined MTP3-User procedures.
The DUNA message contains the following parameters: The DUNA message contains the following parameters:
Network Appearance Optional Network Appearance Optional
Affected Destinations Mandatory Affected Destinations Mandatory
Info String Optional Info String Optional
The format for DUNA Message parameters is as follows: The format for DUNA Message parameters is as follows:
0 1 2 3 0 1 2 3
skipping to change at page 34, line 33 skipping to change at page 37, line 39
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 4 | Length | | Tag = 4 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
\ \ \ \
/ INFO String* / / INFO String* /
\ \ \ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Network Appearance: 32-bit unsigned integer Network Appearance: 32-bit unsigned integer
The optional Network Appearance parameter identifies the SS7 network See Section 3.3.1
context for the message, for the purposes of logically separating
the signalling traffic between the SG and the Application Server
Process over a common SCTP Association. An example is where an SG
is logically partitioned to appear as an element in four different
national SS7 networks.
In an SSNM message, the Network Appearance parameter defines the
format of the Affected DPC(s) in the Affected Destination parameter.
The DPC point code length (e.g., 14-, 16-, or 24-bit) and sub-field
definitions (e.g., ANSI 24-bit network/cluster/member, ITU-
international 14-bit zone/region/signal_point, many national field
variants, ...) are fixed within a particular Network Appearance.
Where an SG operates in the context of a single SS7 network, or
individual SCTP associations are dedicated to each SS7 network
context, the Network Appearance parameter is not required and the
format of the Affected DPC(s) is understood implicitly.
The format of the Network Appearance parameter is an integer, the
values used are of local significance only, coordinated between the
SG and ASP.
Where the optional Network Appearance parameter is present, it must
be the first parameter in the message as it defines the format of
the Affected DPCs in the Affected Destination parameter.
Affected Destinations: n x 32-bits Affected Destinations: n x 32-bits
The Affected Destinations parameter contains up to sixteen Affected The Affected Destinations parameter contains up to sixteen Affected
Destination Point Code fields, each a three-octet parameter to allow Destination Point Code fields, each a three-octet parameter to allow
for 14-, 16- and 24-bit binary formatted SS7 Point Codes. Affected for 14-, 16- and 24-bit binary formatted SS7 Point Codes. Affected
Point Codes that are less than 24-bits, are padded on the left to Point Codes that are less than 24-bits, are padded on the left to
the 24-bit boundary. The encoding is shown below for ANSI and ITU the 24-bit boundary. The encoding is shown below for ANSI and ITU
Point Code examples. Point Code examples.
skipping to change at page 36, line 11 skipping to change at page 38, line 49
useful when reception of an MTP3 management message or a linkset useful when reception of an MTP3 management message or a linkset
event simultaneously affects the availability status of a series of event simultaneously affects the availability status of a series of
destinations at an SG. For example, if all DPCs in an ANSI cluster destinations at an SG. For example, if all DPCs in an ANSI cluster
are determined to be unavailable due to local linkset are determined to be unavailable due to local linkset
unavailability, the DUNA could identify potentially 256 Affected unavailability, the DUNA could identify potentially 256 Affected
DPCs in a single Affected DPC field. DPCs in a single Affected DPC field.
The Mask parameter represents a bit mask that can be applied to the The Mask parameter represents a bit mask that can be applied to the
related Affected DPC field. The bit mask identifies how many bits related Affected DPC field. The bit mask identifies how many bits
of the Affected DPC field are significant and which are effectively of the Affected DPC field are significant and which are effectively
"wildcarded". For example, a mask of "8" indicates that the last "wildcarded". For example, a mask of "8" indicates that the least
eight bits of the DPC is "wildcarded". For an ANSI 24-bit Affected significant eight bits of the DPC is "wildcarded". For an ANSI 24-
DPC, this is equivalent to signalling that all DPCs in an ANSI bit Affected DPC, this is equivalent to signalling that all DPCs in
Cluster are unavailable. A mask of "3" indicates that the last an ANSI Cluster are unavailable. A mask of "3" indicates that the
three bits of the DPC is "wildcarded". For a 14-bit ITU Affected least significant three bits of the DPC is "wildcarded". For a 14-
DPC, this is equivalent to signaling that an ITU Region is bit ITU Affected DPC, this is equivalent to signaling that an ITU
unavailable. A mask value equal to the number of bits in the DPC Region is unavailable. A mask value equal to the number of bits in
indicates that the entire network appearance is affected - this is the DPC indicates that the entire network appearance is affected
used to indicate network isolation to the ASP. this is used to indicate network isolation to the ASP.
Info String: variable length Info String: variable length
The optional INFO String parameter can carry any meaningful 8-BIT The optional INFO String parameter can carry any 8-bit ASCII
ASCII character string along with the message. Length of the INFO character string along with the message. Length of the INFO
String parameter is from 0 to 255 characters. No procedures are String parameter is from 0 to 255 characters. No procedures are
presently identified for its use but the INFO String may be used by presently identified for its use but the INFO String MAY be used by
Operators to identify in text form the location reflected by the Operators to identify in text form the location reflected by the
Affected DPC for debugging purposes. Affected DPC for debugging purposes.
3.4.2 Destination Available (DAVA) 3.4.2 Destination Available (DAVA)
The DAVA message is sent from the SG to all concerned ASPs to indicate The DAVA message is sent from the SG to all concerned ASPs to indicate
that the SG has determined that one or more SS7 destinations are now that the SG has determined that one or more SS7 destinations are now
reachable, or in response to a DAUD message if appropriate. The ASP reachable (and not restricted), or in response to a DAUD message if
MTP3-User protocol is expected to resume traffic to the affected appropriate. The ASP MTP3-User protocol is allowed to resume traffic to
destination through the SG initiating the DUNA. the affected destination through the SG initiating the DUNA.
The DAVA message contains the following parameters: The DAVA message contains the following parameters:
Network Appearance Optional Network Appearance Optional
Affected Destinations Mandatory Affected Destinations Mandatory
Info String Optional Info String Optional
The format and description of the Network Appearance, Affected The format and description of the Network Appearance, Affected
Destinations and Info String parameters is the same as for the DUNA Destinations and Info String parameters is the same as for the DUNA
message (See Section 3.4.1.) message (See Section 3.4.1.)
skipping to change at page 37, line 28 skipping to change at page 40, line 15
to an ASP in response to a DATA or DAUD message as appropriate. For to an ASP in response to a DATA or DAUD message as appropriate. For
some MTP protocol variants (e.g., ANSI MTP) the SCON may be sent when some MTP protocol variants (e.g., ANSI MTP) the SCON may be sent when
the SS7 congestion level changes. The SCON message MAY also be sent the SS7 congestion level changes. The SCON message MAY also be sent
from the M3UA of an ASP to an M3UA peer indicating that the M3UA or the from the M3UA of an ASP to an M3UA peer indicating that the M3UA or the
ASP is congested. ASP is congested.
The SCON message contains the following parameters: The SCON message contains the following parameters:
Network Appearance Optional Network Appearance Optional
Affected Destinations Mandatory Affected Destinations Mandatory
Congestion Indications Optional Concerned Destination Optional Congestion Indications
Optional
Info String Optional Info String Optional
The format for SCON Message parameters is as follows: The format for SCON Message parameters is as follows:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 1 | Length =8 | | Tag = 1 | Length =8 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Network Appearance* | | Network Appearance* |
skipping to change at page 38, line 22 skipping to change at page 40, line 38
| Tag = 5 | Length | | Tag = 5 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Mask | Affected DPC 1 | | Mask | Affected DPC 1 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
\ \ \ \
/ ... / / ... /
\ \ \ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Mask | Affected DPC n | | Mask | Affected DPC n |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 15 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| reserved | Concerned DPC |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 14 | Length | | Tag = 14 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reserved | Cong. Level* | | Reserved | Cong. Level* |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 4 | Length | | Tag = 4 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
\ \ \ \
/ INFO String* / / INFO String* /
\ \ \ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
skipping to change at page 38, line 46 skipping to change at page 41, line 18
The Affected Destinations parameter can be used to indicate congestion The Affected Destinations parameter can be used to indicate congestion
of multiple destinations or ranges of destinations. However, an SCON of multiple destinations or ranges of destinations. However, an SCON
MUST not be delayed in order to "collect" individual congested MUST not be delayed in order to "collect" individual congested
destinations into a single SCON as any delay might affect the timing of destinations into a single SCON as any delay might affect the timing of
congestion indications to the M3UA Users. One use for including a congestion indications to the M3UA Users. One use for including a
range of Congested DPCs is when the SG supports an ANSI cluster route range of Congested DPCs is when the SG supports an ANSI cluster route
set to the SS7 network that becomes congested due to outgoing link set set to the SS7 network that becomes congested due to outgoing link set
congestion. congestion.
Concerned Destination: 32-bits
The optional Concerned Destination parameter is only used if the
SCON is sent from an ASP to the SG. It contains the point code of
the originator of the message that triggered the SCON. The Concerned
Destination parameter contains one Concerned Destination Point Code
field, a three-octet parameter to allow for 14-, 16- and 24-bit
binary formatted SS7 Point Codes. A Concerned Point Code that is
less than 24-bits, is padded on the left to the 24-bit boundary. The
SG sends a Transfer Controlled Message to the Concerned Point Code
using the single Affected DPC contained in the SCON to populate the
(affected) Destination field of the TFC message. Normally the
Affected DPC will be equal to the point code of the ASP.
Congested Indications: 32-bits Congested Indications: 32-bits
The optional Congestion Indications parameter contains a Congestion The optional Congestion Indications parameter contains a Congestion
Level field. This optional parameter is used to communicate Level field. This optional parameter is used to communicate
congestion levels in national MTP networks with multiple congestion congestion levels in national MTP networks with multiple congestion
thresholds, such as in ANSI MTP3. For MTP congestion methods thresholds, such as in ANSI MTP3. For MTP congestion methods
without multiple congestion levels (e.g., the ITU international without multiple congestion levels (e.g., the ITU international
method) the parameter is not included. method) the parameter is not included.
Congestion Level field: 8-bits (unsigned integer) Congestion Level field: 8-bits (unsigned integer)
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MTP3 protocol variant/version recommendation is definitive. MTP3 protocol variant/version recommendation is definitive.
0 to 2 Reserved 0 to 2 Reserved
3 SCCP 3 SCCP
4 TUP 4 TUP
5 ISUP 5 ISUP
6 to 8 Reserved 6 to 8 Reserved
9 Broadband ISUP 9 Broadband ISUP
10 Satellite ISUP 10 Satellite ISUP
The Affected Destinations parameter in a DUPU message differs from the The format and description of the Affected Destinations parameter is
Affected Destinations parameter in the DUNA, DAVA, and DAUD in that the the same as for the DUNA message (See Section 3.4.1.) except that the
Mask field is not used and only a single Affected DPC is attached. Mask field is not used and only a single Affected DPC is included.
Ranges and lists of Affected DPCs cannot be signaled, but this is Ranges and lists of Affected DPCs cannot be signaled in a DUPU, but
consistent with operation in the SS7 network. The Affected Destinations this is consistent with UPU operation in the SS7 network. The Affected
parameter in an MTP3 User Part Unavailable message (UPU) received by an Destinations parameter in an MTP3 User Part Unavailable message (UPU)
SG from the SS7 network contains only one destination. received by an SG from the SS7 network contains only one destination.
The format and description of the Network Appearance and Info String The format and description of the Network Appearance and Info String
parameters is the same as for the DUNA message (See Section 3.4.1.). parameters is the same as for the DUNA message (See Section 3.4.1.).
3.4.6 Destination Restricted (DRST)
The DRST message is optionally sent from the SG to all concerned ASPs
to indicate that the SG has determined that one or more SS7
destinations are now restricted, or in response to a DAUD message if
appropriate. The M3UA at the ASP is expected to send traffic to the
affected destination via an alternate SG of equal priority, but only if
such an alternate route exists and is available. If the affected
destination is currently considered unavailable by the ASP, traffic to
the affected destination through the SG initiating the DRST should be
resumed.
This message is optional for the SG to send and optional for the ASP to
process. It is for use in the "STP" case described in Section 1.4.2.
The DRST message contains the following parameters:
Network Appearance Optional
Affected Destinations Mandatory
Info String Optional
The format and description of the Network Appearance, Affected
Destinations and Info String parameters is the same as for the DUNA
message (See Section 3.4.1.)
3.5 Application Server Process Maintenance (ASPM) Messages 3.5 Application Server Process Maintenance (ASPM) Messages
3.5.1 ASP Up (ASPUP) 3.5.1 ASP Up (ASPUP)
The ASP UP (ASPUP) message is used to indicate to a remote M3UA peer The ASP UP (ASPUP) message is used to indicate to a remote M3UA peer
that the Adaptation layer is ready to receive SSNM or ASPM management that the Adaptation layer is ready to receive SSNM or ASPM management
messages for all Routing Keys that the ASP is configured to serve. messages for all Routing Keys that the ASP is configured to serve.
The ASPUP message contains the following parameters: The ASPUP message contains the following parameters:
skipping to change at page 42, line 11 skipping to change at page 45, line 27
/ INFO String* / / INFO String* /
\ \ \ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The format and description of the optional Info String parameter is the The format and description of the optional Info String parameter is the
same as for the DUNA message (See Section 3.4.1.) same as for the DUNA message (See Section 3.4.1.)
3.5.3 ASP Down (ASPDN) 3.5.3 ASP Down (ASPDN)
The ASP Down (ASPDN) message is used to indicate to a remote M3UA peer The ASP Down (ASPDN) message is used to indicate to a remote M3UA peer
that the adaptation layer is not ready to receive traffic or management that the adaptation layer is NOT ready to receive traffic or
messages. maintenance messages.
The ASPDN message contains the following parameters: The ASPDN message contains the following parameters:
Reason Mandatory Reason Mandatory
INFO String Optional INFO String Optional
The format for the ASPDN message parameters is as follows: The format for the ASPDN message parameters is as follows:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
skipping to change at page 42, line 51 skipping to change at page 46, line 21
adaptation layer is unavailable. The valid values for Reason are adaptation layer is unavailable. The valid values for Reason are
shown in the following table. shown in the following table.
0 Unspecified 0 Unspecified
1 User Unavailable 1 User Unavailable
2 Management Blocking 2 Management Blocking
3.5.4 ASP Down Ack 3.5.4 ASP Down Ack
The ASP Down Ack message is used to acknowledge an ASP-Down message The ASP Down Ack message is used to acknowledge an ASP-Down message
received from a remote M3UA peer. received from a remote M3UA peer, or to reply to an ASPM message from
an ASP which is locked out for management reasons.
The ASP Down Ack message contains the following parameters: The ASP Down Ack message contains the following parameters:
Reason Mandatory Reason Mandatory
INFO String Optional INFO String Optional
The format for the ASPDN Ack message parameters is as follows: The format for the ASPDN Ack message parameters is as follows:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
skipping to change at page 43, line 32 skipping to change at page 46, line 51
/ INFO String* / / INFO String* /
\ \ \ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The format and description of the optional Info String parameter is the The format and description of the optional Info String parameter is the
same as for the DUNA message (See Section 3.4.1.) same as for the DUNA message (See Section 3.4.1.)
The format of the Reason parameter is the same as for the ASP-Down The format of the Reason parameter is the same as for the ASP-Down
message. (See Section 3.4.3) message. (See Section 3.4.3)
3.5.5 Registration Request (REG REQ)
The REG REQ message is sent by an ASP to indicate to a remote M3UA peer
that it wishes to register one or more given Routing Key with the
remote peer. Typically, an ASP would send this message to an SGP, and
expects to receive a REG RSP in return with an associated Routing
Context value.
The REG REQ message contains the following parameters:
Routing Key Mandatory
The format for the REG REQ message is as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 16 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
\ \
/ Routing Key 1 /
\ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
\ \
/ ... /
\ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 16 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
\ \
/ Routing Key n /
\ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Routing Key: variable length
The Routing Key parameter is mandatory. The sender of this message
expects that the receiver of this message will create a Routing
Key entry and assign a unique Routing Context value to it, if the
Routing Key entry does not already exist.
The Routing Key parameter may be present multiple times in the same
message. This is used to allow the registration of multiple Routing
Keys in a single message.
The format of the Routing Key parameter is as follows.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Local-RK-Identifier |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Destination Point Code |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Network Appearance (optional) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SI (optional) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SSN (optional) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Origination Point Code List (optional) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Circuit Range List (optional) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Local-RK-Identifier: 32-bit integer
The mandatory Local-RK-Identifier field is used to uniquely identify
the registration request. The Identifier value is assigned by the
ASP, and is used to correlate the response in an REG RSP message
with the original registration request. The Identifier value must
remain unique until the REG RSP is received.
The format of the Local-RK-Identifier field is as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 19 | Length = 8 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Local-RK-Identifier value |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Destination Point Code:
The Destination Point Code parameter is mandatory, and identifies
the Destination Point Code of incoming SS7 traffic for which the ASP
is registering. The format is the same as described for the
Affected Destination parameter in the DUNA Message (See Section
3.4.1). Its format is:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 20 | Length = 8 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Mask = 0 | Destination Point Code |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Network Appearance:
The optional Network Appearance parameter field identifies the SS7
Network context for the Routing Key, and has the same format as in
the Data message (See Section 3.3.1). Its format is:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 1 | Length = 8 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Network Appearance |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Service Indicators (SI): n X 8-bit integers
The SI field contains one or more Service Indicators from the values
as described in the MTP3-User Identity field of the DUPU Message.
The absence of the SI parameter in the Routing Key indicates the use
of any SI values, excluding of course MTP management. Where an SI
parameter does not contain a multiple of four SIs, the parameter is
padded out to 32-byte alignment. An SI value of zero is not valid
in M3UA. The SI format is:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 21 | Length = var. |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SI #1 | SI #2 | SI #3 | SI #4 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ ... /
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SI #n | 0 Padding, if necessary |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Subsystem Numbers (SSN): n X 8-bit integers
The optional SSN field contains one or more SCCP subsystem numbers,
and is used in conjunction with an SI values of 3 (i.e., SCCP) only.
Where an SSN parameter does not contain a multiple of four SSNs, the
parameter is padded out to 32-byte alignment. The subsystem number
values associated are defined by the local network operator, and
typically follow ITU-T Recommendation Q.713. An SSN value of zero
is not valid in M3UA. The format of this field is as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 22 | Length = var. |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SSN #1 | SSN #2 | SSN #3 | SSN #4 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ ... /
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SSN #n | 0 Padding, if necessary |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
OPC List:
The Originating Point Code List parameter contains one or more SS7
OPC entries, and its format is the same as the Destination Point
Code parameter.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 23 | Length = var. |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Mask = 0 | Origination Point Code #1 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Mask = 0 | Origination Point Code #2 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ ... /
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Mask = 0 | Origination Point Code #n |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Circuit Range:
An ISUP controlled circuit is uniquely identified by the SS7 OPC,
DPC and CIC value. For the purposes of identifying Circuit Ranges
in an M3UA Routing Key, the optional Circuit Range parameter
includes one or more circuit ranges, each identified by an OPC and
Upper/Lower CIC value. The DPC is implicit as it is mandatory and
already included in the DPC parameter of the Routing Key. The
Origination Point Code is encoded the same as the Destination Point
Code parameter, while the CIC values are 16-bit integers.
The Circuit Range format is as follows:
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 24 | Length = var. |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Mask = 0 | Origination Point Code #1 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Lower CIC Value #1 | Upper CIC Value #1 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Mask = 0 | Origination Point Code #2 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Lower CIC Value #2 | Upper CIC Value #2 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ ... /
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Mask = 0 | Origination Point Code #n |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Lower CIC Value #n | Upper CIC Value #n |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3.5.6 Registration Response (REG RSP)
The REG RSP message is used as a response to the REG REQ message from a
remote M3UA peer. It contains indications of success/failure for
registration requests and returns a unique Routing Context value for
successful registration requests, to be used in subsequent M3UA Traffic
Management protocol.
The REG RSP message contains the following parameters:
Registration Results Mandatory
The format for the REG RSP message is as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 25 | Length = var. |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Registration Result 1 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ ... /
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Registration Result n |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Registration Results:
The Registration Results parameter contains one or more results,
each containing the registration status for a single Routing Key in
an REG REQ message. The number of results in a single REG RSP
message MAY match the number of Routing Key parameters found in the
corresponding REG REQ message. The format of each result is as
follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Local-RK-Identifier value |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Registration Status |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Routing Context |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Local-RK-Identifier: 32-bit integer
The Local-RK-Identifier contains the same value as found in the
matching Routing Key parameter found in the REG Req message.
Registration Status: 32-bit integer
The Registration Result Status field indicates the success or the
reason for failure of a registration request.
Its values may be:
0 Successfully Registered
1 Error - Unknown
2 Error - Invalid DPC
3 Error - Invalid Network Appearance
4 Error - Invalid Routing Key
5 Error - Permission Denied
6 Error - Overlapping (Non-unique) Routing Key
7 Error - Routing Key not Provisioned
8 Error - Insufficient Resources
Routing Context: 32-bit integer
The Routing Context field contains the Routing Context value for the
associated Routing Key if the registration was successful. It is set
to "0" if the registration was not successful.
3.5.7 De-Registration Request (DEREG REQ)
The DEREG REQ message is sent by an ASP to indicate to a remote M3UA
peer that it wishes to de-register a given Routing Key. Typically, an
ASP would send this message to an SGP, and expects to receive a DEREG
RSP in return with the associated Routing Context value.
The DEREG REQ message contains the following parameters:
Routing Context Mandatory
The format for the DEREG REQ message is as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 6 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
\ \
/ Routing Context /
\ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Routing Context: n X 32-bit integers
The Routing Context parameter contains (a list of) integers indexing
the Application Server traffic that the sending ASP is currently
registered to receive from the SG but now wishes to deregister.
3.5.8 De-Registration Response (DEREG RSP)
The DEREG RSP message is used as a response to the DEREG REQ message
from a remote M3UA peer.
The DEREG RSP message contains the following parameters:
De-registration Results Mandatory
The format for the DEREG RSP message is as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 18 | Length = var |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| De-Registration Result 1 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ ... /
\ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| De-Registration Result n |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
De-Registration Results:
The De-Registration Results parameter contains one or more results,
each containing the de-registration status for a single Routing
Context in a DEREG REQ message. The number of results in a single
DEREG RSP message MAY match the number of Routing Contexts found in
the corresponding DEREG REQ message. The format of each result is
as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Routing Context |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| De-Registration Status |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Routing Context: 32-bit integer
The Routing Context field contains the Routing Context value of the
matching Routing Key to deregister, as found in the DEREG Req.
De-Registration Status: 32-bit integer
The De-Registration Result Status field indicates the success or the
reason for failure of the de-registration.
Its values may be:
0 Successfully De-registered
1 Error - Unknown
2 Error - Invalid Routing Context
3 Error - Permission Denied
4 Error - Not Registered
3.5.5 ASP Active (ASPAC) 3.5.5 ASP Active (ASPAC)
The ASPAC message is sent by an ASP to indicate to a remote M3UA peer The ASPAC message is sent by an ASP to indicate to a remote M3UA peer
that it is Active and ready to process signalling traffic for a that it is Active and ready to process signalling traffic for a
particular Application Server. The ASPAC affects only the ASP state particular Application Server. The ASPAC affects only the ASP state
for the routing keys identified by the Routing Contexts, if present. for the routing keys identified by the Routing Contexts, if present.
The ASPAC message contains the following parameters: The ASPAC message contains the following parameters:
Traffic Mode Type Mandatory Traffic Mode Type Mandatory
skipping to change at page 44, line 37 skipping to change at page 56, line 4
Traffic Mode Type: 32-bit (unsigned integer) Traffic Mode Type: 32-bit (unsigned integer)
The Traffic Mode Type parameter identifies the traffic mode of The Traffic Mode Type parameter identifies the traffic mode of
operation of the ASP within an AS. The valid values for Type are operation of the ASP within an AS. The valid values for Type are
shown in the following table. shown in the following table.
1 Over-ride 1 Over-ride
2 Load-share 2 Load-share
3 Over-ride (Standby) 3 Over-ride (Standby)
4 Load-share (Standby) 4 Load-share (Standby)
Within a particular Routing Context, only one Traffic Mode Type
Within a particular Routing Context, Over-ride and Load-share Types can be used. The Over-ride value indicates that the ASP is
cannot be mixed. The Over-ride value indicates that the ASP is operating in Over-ride mode, and the ASP takes over all
operating in Over-ride mode, and the ASP wishes to take over all
traffic in an Application Server (i.e., primary/back-up operation), traffic in an Application Server (i.e., primary/back-up operation),
over-riding any currently active ASP in the AS. In Load-share mode, over-riding any currently active ASPs in the AS. In Load-share
the ASP wishes to share in the traffic distribution with any other mode, the ASP will share in the traffic distribution with any other
currently active ASPs. The Standby versions of the Over-ride and currently active ASPs. The Standby versions of the Over-ride and
Load-share Types indicate that the ASP is declaring itself ready to Load-share Types indicate that the ASP is declaring itself ready to
accept traffic but leaves it up to the sender as to when the traffic accept traffic but leaves it up to the sender as to when the traffic
is started. Over-ride (Standby) indicates that the traffic sender is started. Over-ride (Standby) indicates that the traffic sender
continues to use the currently active ASP until it can no longer continues to use the currently active ASP until it can no longer
send/receive traffic (i.e., the currently active ASP transitions to send/receive traffic (i.e., the currently active ASP transitions to
Down or Inactive). At this point the sender may immediately move Down or Inactive). At this point the sender MUST move the standby
the ASP to Active and commence traffic. Load-share (Standby) is ASP to Active and commence traffic. Load-share (Standby) is similar
similar - the sender continues to load-share to the current ASPs - the sender continues to load-share to the current ASPs until it is
until there it is determined that there is insufficient resources in determined that there is insufficient resources in
the Load-share group. When there is insufficient ASPs, the sender the Load-share group. When there are insufficient ASPs, the sender
may immediately move the ASP to Active. MUST move the ASP to Active.
Routing Context: Routing Context: n X 32-bit integers
The optional Routing Context parameter contains (a list of) 4-byte The optional Routing Context parameter contains (a list of) integers
unsigned integers indexing the Application Server traffic that the indexing the Application Server traffic that the sending ASP is
sending ASP is configured/registered to receive. configured/registered to receive.
There is one-to-one relationship between an index entry and an SG There is one-to-one relationship between an index entry and an SG
Routing Key or AS Name. Because an AS can only appear in one Routing Key or AS Name. Because an AS can only appear in one
Network Appearance, the Network Appearance parameter is not required Network Appearance, the Network Appearance parameter is not required
in the ASPAC message. in the ASPAC message.
An Application Server Process may be configured to process traffic An Application Server Process may be configured to process traffic
for more than one logical Application Server. From the perspective for more than one logical Application Server. From the perspective
of an ASP, a Routing Context defines a range of signalling traffic of an ASP, a Routing Context defines a range of signalling traffic
that the ASP is currently configured to receive from the SG. For that the ASP is currently configured to receive from the SG. For
example, an ASP could be configured to support call processing for example, an ASP could be configured to support call processing for
multiple ranges of PSTN trunks and therefore receive related multiple ranges of PSTN trunks and therefore receive related
signalling traffic, identified by separate SS7 DPC/OPC/CIC_ranges. signalling traffic, identified by separate SS7 DPC/OPC/CIC_ranges.
The format and description of the optional Info String parameter is the The format and description of the optional Info String parameter is the
same as for the DUNA message (See Section 3.4.1.) same as for the DUNA message (See Section 3.4.1.)
3.5.6 ASP Active Ack 3.5.6 ASP Active Ack
The ASPAC Ack message is used to acknowledge an ASP-Active message The ASPAC Ack message is used to acknowledge an ASP-Active message
received from a remote M3UA peer. received from a remote M3UA peer. In the case where an ASPAC (Over-
ride (standby)) or ASPAC (load-share (standby) is received, a second
ASPACK Ack is sent when the ASP is moved to the "Active" state from
"Active (Standby)".
The ASPAC Ack message contains the following parameters: The ASPAC Ack message contains the following parameters:
Traffic Mode Type Mandatory Traffic Mode Type Mandatory
Routing Context Optional Routing Context Optional
INFO String Optional INFO String Optional
The format for the ASPAC Ack message is as follows: The format for the ASPAC Ack message is as follows:
0 1 2 3 0 1 2 3
skipping to change at page 46, line 36 skipping to change at page 57, line 42
The format and description of the optional Info String parameter is the The format and description of the optional Info String parameter is the
same as for the DUNA message (See Section 3.3.2.1.) same as for the DUNA message (See Section 3.3.2.1.)
The format of the Traffic Mode Type and Routing Context parameters is The format of the Traffic Mode Type and Routing Context parameters is
the same as for the ASP-Active message. (See Section 3.4.5). the same as for the ASP-Active message. (See Section 3.4.5).
3.5.7 ASP Inactive (ASPIA) 3.5.7 ASP Inactive (ASPIA)
The ASPIA message is sent by an ASP to indicate to a remote M3UA peer The ASPIA message is sent by an ASP to indicate to a remote M3UA peer
that it is no longer processing signalling traffic within a particular that it is no longer an active ASP to be used from within a list of
Application Server. The ASPIA affects only the ASP state in the ASPs. The ASPIA affects only the ASP state in the Routing Keys
Routing Keys identified by the Routing Contexts, if present. identified by the Routing Contexts, if present.
The ASPIA message contains the following parameters: The ASPIA message contains the following parameters:
Traffic Mode Type Mandatory
Routing Context Optional Routing Context Optional
INFO String Optional INFO String Optional
The format for the ASPIA message parameters is as follows: The format for the ASPIA message parameters is as follows:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 11 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Traffic Mode Type |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 6 | Length | | Tag = 6 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
\ \ \ \
/ Routing Context* / / Routing Context* /
\ \ \ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 4 | Length | | Tag = 4 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
\ \ \ \
/ INFO String* / / INFO String* /
\ \ \ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Traffic Mode Type: 32-bit (unsigned integer)
The Traffic Mode Type parameter identifies the traffic mode of
operation of the ASP within an AS. The valid values for Type are
shown in the following table.
1 Over-ride
2 Load-share
Within a particular Routing Context, only one Type can be used. The
Over-ride value indicates that the ASP is operating in Over-ride
mode, and will no longer handle traffic within an Application Server
(i.e., it is now a backup in a primary/back-up arrangement). The
Load-share value indicates that the ASP is operating in Load-share
mode and will no longer share in the traffic distribution with any
other currently active ASPs.
A node that receives an ASPIA with an incorrect Type for a
particular routing Context will respond with an Error Message
(Cause: Invalid Traffic Handling Mode).
The format and description of the optional Routing Context and Info The format and description of the optional Routing Context and Info
String parameters is the same as for the ASPAC message (See Section String parameters is the same as for the ASPAC message (See Section
3.5.5.) 3.5.5.)
3.5.8 ASP Inactive Ack 3.5.8 ASP Inactive Ack
The ASPIA Ack message is used to acknowledge an ASP-Inactive message The ASPIA Ack message is used to acknowledge an ASP-Inactive message
received from a remote M3UA peer. received from a remote M3UA peer.
The ASPIA Ack message contains the following parameters: The ASPIA Ack message contains the following parameters:
Traffic Mode Type Mandatory
Routing Context Optional Routing Context Optional
INFO String Optional INFO String Optional
The format for the ASPIA Ack message is as follows: The format for the ASPIA Ack message is as follows:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 11 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Traffic Mode Type |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 6 | Length | | Tag = 6 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
\ \ \ \
/ Routing Context* / / Routing Context* /
\ \ \ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag = 4 | Length | | Tag = 4 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
\ \ \ \
/ INFO String* / / INFO String* /
\ \ \ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The format and description of the optional Info String parameter is the The format and description of the optional Info String parameter is the
same as for the DUNA message (See Section 3.4.1.) same as for the DUNA message (See Section 3.4.1.)
The format of the Traffic Mode Type and Routing Context parameters is The format of the Routing Context parameter is the same as for the ASP-
the same as for the ASP-Inactive message. (See Section 3.5.7). Inactive message. (See Section 3.5.7).
3.5.9 Heartbeat (BEAT) 3.5.9 Heartbeat (BEAT)
The Heartbeat message is optionally used to ensure that the M3UA peers The Heartbeat message is optionally used to ensure that the M3UA peers
are still available to each other. It is recommended for use when the are still available to each other. It is recommended for use when the
M3UA runs over a transport layer other than the SCTP, which has its own M3UA runs over a transport layer other than the SCTP, which has its own
heartbeat. heartbeat.
The BEAT message contains the following parameters: The BEAT message contains the following parameters:
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\ \ \ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Error Code: 32-bits (unsigned integer) Error Code: 32-bits (unsigned integer)
The Error Code parameter indicates the reason for the Error Message. The Error Code parameter indicates the reason for the Error Message.
The Error parameter value can be one of the following values: The Error parameter value can be one of the following values:
1 Invalid Version 1 Invalid Version
2 Invalid Network Appearance 2 Invalid Network Appearance
3 Unsupported Message Type 3 Unsupported Message Class
4 Invalid Message Type 4 Unsupported Message Type
5 Invalid Traffic Handling Mode 5 Unsupported/Invalid Traffic Handling Mode
6 Unexpected Message 6 Unexpected Message
7 Protocol Error 7 Protocol Error
8 Invalid Routing Context 8 Invalid Routing Context
9 Invalid Stream Identifier
10 Invalid Parameter Value
The "Invalid Version" error is sent if a message was received with an
invalid or unsupported version. The Error message contains the
supported version in the Common header. The Error message could
optionally provide the supported version in the Diagnostic Information
area.
The "Invalid Network Appearance" error is sent by a SG if an ASP sends
a message with an invalid (unconfigured) Network Appearance value.
The "Unsupported Message Class" error is sent if a message with an
unexpected or unsupported Message Class is received.
The "Unsupported Message Type" error is sent if a message with an
unexpected or unsupported Message Type is received.
The "Unsupported/Invalid Traffic Handling Mode" error is sent by a SG
if an ASP sends an ASP Active with an unsupported Traffic Handling Mode
or a Traffic Handling mode that is inconsistent with the presently
configured mode for the Application Server. An example would be a case
in which the SG did not support load-sharing.
The "Unexpected Message" error MAY be sent if a defined and recognized
message is received that is not expected in the current state( in some
cases the ASP may optionally silently discard the message and not send
an Error). For example, silent discard is used by an ASP if it
received a Transfer message from an SG while it was in the Inactive
state.
The "Protocol Error" error is sent for any protocol anomaly(i.e.,
reception of a parameter that is syntactically correct but unexpected
in the current situation.
The "Invalid Routing Context" error is sent by an SG if an Asp sends a
message with an invalid (unconfigured) Routing Context value.
The "Invalid Stream Identifier" error is sent if a message was received
on an unexpected SCTP stream (e.g., a MGMT message was received on a
stream other than "0").
The " Invalid Parameter Value " error is sent if a message was received
with an invalid parameter value (e.g., a DUPU message was received with
a Mask value other than "0").
Diagnostic Information: variable length Diagnostic Information: variable length
When included, the optional Diagnostic information can be any When included, the optional Diagnostic information can be any
information germane to the error condition, to assist in information germane to the error condition, to assist in
identification of the error condition. In the case of an Invalid identification of the error condition. In the case of an Invalid
Network Appearance, Traffic Handling Mode or Routing Context, the Network Appearance, Traffic Handling Mode, Routing Context or
Diagnostic information includes the received parameter. In the Parameter Value, the Diagnostic information includes the received
other cases, the Diagnostic information may be the first 40 bytes of parameter. In the other cases, the Diagnostic information may be
the offending message. the first 40 bytes of the offending message.
In the case of an Invalid Version Error Code, the Common Header
contains the supported Version.
Error messages are not generated in response to other Error messages. Error messages are not generated in response to other Error messages.
3.6.2 Notify (NTFY) 3.6.2 Notify (NTFY)
The Notify message used to provide an autonomous indication of M3UA The Notify message used to provide an autonomous indication of M3UA
events to an M3UA peer. events to an M3UA peer.
The NTFY message contains the following parameters: The NTFY message contains the following parameters:
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| Tag = 4 | Length | | Tag = 4 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
\ \ \ \
/ INFO String* / / INFO String* /
\ \ \ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Status Type: 16-bits (unsigned integer) Status Type: 16-bits (unsigned integer)
The Status Type parameter identifies the type of the Notify message. The Status Type parameter identifies the type of the Notify message.
Following are the valid Status Type values: The following are the valid Status Type values:
1 Application Server State Change (AS-StateChange) 1 Application Server State Change (AS-StateChange)
2 Other 2 Other
Status Information: 16-bits (unsigned integer) Status Information: 16-bits (unsigned integer)
The Status Information parameter contains more detailed information The Status Information parameter contains more detailed information
for the notification, based on the value of the Status Type. for the notification, based on the value of the Status Type.
If the Status Type is AS_State_Change the following Status If the Status Type is AS_State_Change the following Status
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For the Alternate ASP Active case, an ASP is informed when an alternate For the Alternate ASP Active case, an ASP is informed when an alternate
ASP transitions to the ASP-Active state in Over-ride mode. ASP transitions to the ASP-Active state in Over-ride mode.
The format and description of the optional Routing Context and Info The format and description of the optional Routing Context and Info
String parameters is the same as for the ASPAC message (See Section String parameters is the same as for the ASPAC message (See Section
3.4.6.) 3.4.6.)
4.0 Procedures 4.0 Procedures
The M3UA layer needs to respond to various local primitives it receives The M3UA layer needs to respond to various local primitives it receives
from the SCTP and M3UA-User layers and Layer Management as well as the from other layers as well as the messages that it receives from the
messages that it receives from the peer M3UA layers. This section peer M3UA layer. This section describes the M3UA procedures in
describes the M3UA procedures in response to these events. response to these events.
4.1 Procedures to support the services of the M3UA layer 4.1 Procedures to support the services of the M3UA layer
4.1.1 Receipt of primitives from the M3UA-User 4.1.1 Receipt of primitives from the M3UA-User
On receiving an MTP-Transfer request primitive from an upper layer, or On receiving an MTP-Transfer request primitive from an upper layer, or
the nodal inter-working function at an SG, the M3UA layer sends a the nodal inter-working function at an SG, the M3UA layer sends a
corresponding DATA message (see Section 3) to its M3UA peer. The M3UA corresponding DATA message (see Section 3) to its M3UA peer. The M3UA
peer receiving the Data message sends an MTP-Transfer indication peer receiving the Data message sends an MTP-Transfer indication
primitive to the upper layer. primitive to the upper layer.
The M3UA address translation and mapping function determines the The M3UA message distribution function (see Section 1.4.2.1) determines
Application Server (AS) based on the information in the incoming the Application Server (AS) based on comparing the information in the
message. From the list of ASPs within the AS table, an Active ASP is MTP-Transfer request primitive with a provisioned Routing Key.
selected and a DATA message is constructed and issued on the
corresponding SCTP Association. If more than one ASP is active (i.e., >From the list of ASPs within the AS table, an Active ASP is selected
traffic is to be load-shared across all the active ASPs), one of the and a DATA message is constructed and issued on the corresponding SCTP
active ASPs from the list is selected. The selection algorithm is Association. If more than one ASP is active (i.e., traffic is to be
implementation dependent but could, for example, be round-robin or load-shared across all the active ASPs), one of the active ASPs from
based on, for example, the SLS or ISUP CIC. The appropriate selection the list is selected. The selection algorithm is implementation
algorithm must be chosen carefully as it is dependent on application dependent but could, for example, be round-robin or based on, for
assumptions and understanding of the degree of state coordination example, the SLS or ISUP CIC. The appropriate selection algorithm must
between the active ASPs in the AS. be chosen carefully as it is dependent on application assumptions and
understanding of the degree of state coordination between the active
ASPs in the AS.
In addition, the message needs to be sent on the appropriate SCTP In addition, the message needs to be sent on the appropriate SCTP
stream, again taking care to meet the message sequencing needs of the stream, again taking care to meet the message sequencing needs of the
signalling application. signalling application.
When there is no Routing Key match, or only a partial match, for an
incoming SS7 message, a default treatment must be specified. Possible
solutions are to provide a default Application Server at the SG that
directs all unallocated traffic to a (set of) default ASP(s), or to
drop the message and provide a notification to management in an M-Error
indication primitive. The treatment of unallocated traffic is
implementation dependent.
4.1.2 Receipt of primitives from the Layer Management 4.1.2 Receipt of primitives from the Layer Management
On receiving primitives from the local Layer Management, the M3UA On receiving primitives from the local Layer Management, the M3UA layer
layer will take the requested action and provide a response to Layer will take the requested action and provide an appropriate response
Management. primitive to Layer Management.
An M-SCTP ESTABLISH request from Layer Management will initiate the An M-SCTP ESTABLISH request from Layer Management at an ASP or IPSP
establishment of an SCTP association. An M-SCTP ESTABLISH confirm will will initiate the establishment of an SCTP association. The M3UA layer
be sent to Layer Management when the initiated association set-up is will attempt to establish an SCTP association with the remote M3UA peer
complete. An M-SCTP ESTABLISH indication is sent to Layer Management at by sending an SCTP-Associate primitive to the local SCTP layer.
upon successful completion of an incoming SCTP association set-up from
a peer M3UA node
An M-SCTP RELEASE request from Layer Management initates the tear- When an SCTP association has been successfully established, the SCTP
down of an SCTP association. An M-SCTP RELEASE confirm is sent to will send an SCTP-Communication Up notification to the local M3UA
Layer Management when the association teardown is complete. An M-SCTP layer. At the SG or IPSP that initiated the request, the M3UA will
RELEASE indication is sent to Layer Management upon successful tear- send an M-SCTP ESTABLISH confirm to Layer Management when the
down of an SCTP association initiated by a peer M3UA association set-up is complete. At the peer M3UA layer, an M-SCTP
ESTABLISH indication is sent to Layer Management upon successful
completion of an incoming SCTP association set-up.
An M-SCTP RELEASE request from Layer Management initates the tear-down
of an SCTP association. M3UA accomplishes a graceful shutdown of the
SCTP association by sending a SHUTDOWN primitive to the SCTP layer.
When the graceful shutdown of the SCTP association has been
accomplished, the SCTP layer returns a SHUTDOWN COMPLETE notification
to the local M3UA Layer. At the M3UA Layer that initiated the request,
the M3UA will send an M-SCTP RELEASE confirm to Layer Management when
the association teardown is complete. At the peer M3UA Layer, an M-
SCTP RELEASE indication is sent to Layer Management upon successful
tear-down of an SCTP association.
An M-SCTP STATUS request supports a Layer Management query of the local An M-SCTP STATUS request supports a Layer Management query of the local
status of a particular SCTP association. The M3UA responds with the status of a particular SCTP association. The M3UA simply maps the M-
association status in an M-SCTP STATUS confirm. No peer protocol is SCTP STATUS request to a STATUS primitive to the SCTP. When the SCTP
invoked. responds, the M3UA maps the association status information to an M-SCTP
STATUS confirm. No peer protocol is invoked.
Similar LM-to-M3UA-to-SCTP and/or SCTP-to-M3UA-LM mappings can be
described for the various other SCTP Upper layer primitives in RFC2960
such as Initialize, Set Primary, Change Heartbeat, Request Heartbeat,
Get SRTT Report, Set Failure Threshold, Set Protocol parameters,
Destroy SCTP Instance, Send Failure, and Network Status Change.
Alternatively, these SCTP Upper Layer primitives (and Status as well)
can be considered for modeling purposes as a Layer Management
interaction directly with the SCTP Layer.
M-NOTIFY indication and M-ERROR indication primitives indicate to Layer
Management the notification or error information contained in a
received M3UA Notify or Error message respectively. These indications
can also be generated based on local M3UA events.
An M-ASP STATUS request supports a Layer Management query of the status An M-ASP STATUS request supports a Layer Management query of the status
of a particular local or remote ASP. The M3UA responds with the status of a particular local or remote ASP. The M3UA responds with the status
in an M-ASP STATUS confirm. No M3UA peer protocol is invoked. in an M-ASP STATUS confirm. No M3UA peer protocol is invoked.
An M-AS STATUS request supports a Layer Management query of the status An M-AS STATUS request supports a Layer Management query of the status
of a particular AS. The M3UA responds with an M-AS STATUS confirm. No of a particular AS. The M3UA responds with an M-AS STATUS confirm. No
M3UA peer protocol is invoked. M3UA peer protocol is invoked.
M-ASP-UP request, M-ASP-DOWN request, M-ASP-ACTIVE request and M-ASP- M-ASP-UP request, M-ASP-DOWN request, M-ASP-ACTIVE request and M-ASP-
INACTIVE request primitives allow Layer Management at an ASP to INACTIVE request primitives allow Layer Management at an ASP to
initiate state changes. Upon successful completion, a corresponding initiate state changes. Upon successful completion, a corresponding
confirm is provided by the M3UA to Layer Management. If the invocation confirm is provided by the M3UA to Layer Management. If an invocation
is unsuccessful, an Error indication is provided. is unsuccessful, an Error indication is provided.
These requests result in outgoing M3UA ASP-UP, ASP-DOWN, ASP-ACTIVE and These requests result in outgoing M3UA ASP-UP, ASP-DOWN, ASP-ACTIVE and
ASP-INACTIVE messages to the remote M3UA peer at an SG or IPSP. ASP-INACTIVE messages to the remote M3UA peer at an SG or IPSP.
4.2 Receipt of M3UA Peer Management messages 4.2 Receipt of M3UA Peer Management messages
Upon successful state changes resulting from reception of M3UA ASP-UP, Upon successful state changes resulting from reception of M3UA ASP-UP,
ASP-DOWN, ASP-ACTIVE and ASP-INACTIVE messages from a peer M3UA, the ASP-DOWN, ASP-ACTIVE and ASP-INACTIVE messages from a peer M3UA, the
M3UA layer invoke corresponding M-ASP UP, M-ASP DOWN, M-ASP ACTIVE and
M-ASP INACTIVE, M-AS ACTIVE, M-AS INACTIVE, and M-AS DOWN indications M3UA layer MUST invoke corresponding M-ASP UP, M-ASP DOWN, M-ASP ACTIVE
as appropriate to the Layer Management. and M-ASP INACTIVE, M-AS ACTIVE, M-AS INACTIVE, and M-AS DOWN
indications to the local Layer Management.
M-NOTIFY indication and M-ERROR indication indicate to Layer Management M-NOTIFY indication and M-ERROR indication indicate to Layer Management
the notification or error information contained in a received M3UA the notification or error information contained in a received M3UA
Notify or Error message. These indications can also be generated based Notify or Error message. These indications can also be generated based
on local M3UA events. on local M3UA events.
4.3 Procedures to support the M3UA Management services 4.3 Procedures to support the M3UA Management services
These procedures support the M3UA management of SCTP Associations These procedures support the M3UA management of SCTP Associations
between SGs and ASPs. between SGs and ASPs.
4.3.1 AS and ASP State Maintenance 4.3.1 AS and ASP State Maintenance
The M3UA layer on the SG maintains the state of each remote ASP, in The M3UA layer on the SG maintains the state of each remote ASP, in
each Application Server that the ASP is configured to receive traffic, each Application Server that the ASP is configured to receive traffic,
as input to the M3UA message distribution function. Similarly, where as input to the M3UA message distribution function. Similarly, where
IPSPs use M3UA in a point-to-point fashion, the M3UA layer in an IPSP IPSPs use M3UA in a point-to-point fashion, the M3UA layer in an IPSP
maintains the state of remote ASPs in IPSPs. For the purposes of the maintains the state of remote IPSPs. For the purposes of the following
following procedures, only the SG/ASP case is described but the SG side procedures, only the SG/ASP case is described but the SG side of the
of the procedures also apply to an IPSP sending traffic to an AS procedures also apply to an IPSP sending traffic to an AS consisting of
consisting of remote ASPs in IPSPs. a set of remote IPSPs.
4.3.1.1 ASP States 4.3.1.1 ASP States
The state of each remote ASP, in each AS that it is configured to The state of each remote ASP, in each AS that it is configured to
operate, is maintained in the M3UA layer in the SG or IPSP. The state operate, is maintained in the M3UA layer in the SG. The state of a
of a particular ASP in a particular AS changes due to events. The particular ASP in a particular AS changes due to events. The events
events include: include:
* Reception of messages from the peer M3UA layer at the ASP * Reception of messages from the peer M3UA layer at the ASP;
* Reception of some messages from the peer M3UA layer at other ASPs * Reception of some messages from the peer M3UA layer at other ASPs
in the AS (e.g., ASPAC Take-over) in the AS (e.g., ASPAC Take-over);
* Reception of indications from the SCTP layer * Reception of indications from the SCTP layer; or
* Local Management intervention.
The ASP state transition diagram is shown in Figure 4. The possible The ASP state transition diagram is shown in Figure 4. The possible
states of an ASP are: states of an ASP are:
ASP-DOWN: The remote M3UA peer at the ASP is unavailable and/or the ASP-DOWN: The remote M3UA peer at the ASP is unavailable and/or the
related SCTP association is down. Initially all ASPs will be in this related SCTP association is down. Initially all ASPs will be in this
state. An ASP in this state should not be sent any M3UA messages. state. An ASP in this state should not be sent any M3UA messages.
ASP-INACTIVE: The remote M3UA peer at the ASP is available (and the ASP-INACTIVE: The remote M3UA peer at the ASP is available (and the
related SCTP association is up) but application traffic is stopped. In related SCTP association is up) but application traffic is stopped. In
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application traffic is active (for a particular Routing Context or set application traffic is active (for a particular Routing Context or set
of Routing Contexts). of Routing Contexts).
ASP-STANDBY: The remote M3UA peer at the ASP is available and ready to ASP-STANDBY: The remote M3UA peer at the ASP is available and ready to
receive application traffic at any time (for a particular Routing receive application traffic at any time (for a particular Routing
Context or set of Routing Contexts). In this state the ASP can be sent Context or set of Routing Contexts). In this state the ASP can be sent
any non-Data M3UA messages. any non-Data M3UA messages.
Figure 4: ASP State Transition Diagram Figure 4: ASP State Transition Diagram
+-------------+ +--------------+
| ASP-ACTIVE | | ASP-ACTIVE |
+----------------------| or | +----------------------| or |
| Alternate +-------| ASP-STNDBY* | | Alternate +-------| ASP-STANDBY* |
| ASP | +-------------+ | ASP | +--------------+
| Takeover | ^ | | Takeover | ^ |
| | ASP | | ASP | | ASP | | ASP
| | Active | | Inact | | Active | | Inact
| | | v | | | v
| | +-------------+ | | +--------------+
| | | | | | | |
| +------>| ASP-INACT | | +------>| ASP-INACTIVE |
| +-------------+ | +--------------+
| ^ | | ^ |
ASP Down/ | ASP | | ASP Down / ASP Down/ | ASP | | ASP Down /
SCTP CDI | Up | | SCTP CDI SCTP CDI | Up | | SCTP CDI
| | v | | v
| +-------------+ | +--------------+
| | | | | |
+--------------------->| | +--------------------->| ASP-DOWN |
| ASP-DOWN | | |
+-------------+ +--------------+
*Note: ASP-ACTIVE and ASP-STNDBY differ only in whether the ASP is *Note: ASP-ACTIVE and ASP-STANDBY differ only in whether the ASP is
currently receiving Data traffic. currently receiving Data traffic within the AS.
SCTP CDI: The local SCTP layer's Communication Down Indication to the SCTP CDI: The local SCTP layer's Communication Down Indication to the
Upper Layer Protocol (M3UA) on an SG. The local SCTP will send this Upper Layer Protocol (M3UA) on an SG. The local SCTP will send this
indication when it detects the loss of connectivity to the ASP's peer indication when it detects the loss of connectivity to the ASP's peer
SCTP layer. SCTP CDI is understood as either a SHUTDOWN COMPLETE SCTP layer. SCTP CDI is understood as either a SHUTDOWN COMPLETE
notification or COMMUNICATION LOST notification from the SCTP. notification or COMMUNICATION LOST notification from the SCTP.
4.3.1.2 AS States 4.3.1.2 AS States
The state of the AS is maintained in the M3UA layer on the SG. The state of the AS is maintained in the M3UA layer on the SG.
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* Recovery timer triggers * Recovery timer triggers
The possible states of an AS are: The possible states of an AS are:
AS-DOWN: The Application Server is unavailable. This state implies AS-DOWN: The Application Server is unavailable. This state implies
that all related ASPs are in the ASP-DOWN state for this AS. Initially that all related ASPs are in the ASP-DOWN state for this AS. Initially
the AS will be in this state. the AS will be in this state.
AS-INACTIVE: The Application Server is available but no application AS-INACTIVE: The Application Server is available but no application
traffic is active (i.e., one or more related ASPs are in the ASP- traffic is active (i.e., one or more related ASPs are in the ASP-
Inactive state, but none in the ASP-Active state). Inactive state, but none in the ASP-Active state). The recovery timer
T(r) is not running or has expired.
AS-ACTIVE: The Application Server is available and application traffic AS-ACTIVE: The Application Server is available and application traffic
is active. This state implies that at least one ASP is in the ASP- is active. This state implies that at least one ASP is in the ASP-
ACTIVE state. ACTIVE state.
AS-PENDING: An active ASP has transitioned to inactive and it was the AS-PENDING: An active ASP has transitioned to inactive and it was the
last remaining active ASP in the AS (and no STANDBY ASPs are available. last remaining active ASP in the AS (and no STANDBY ASPs are available.
A recovery timer T(r) will be started and all incoming SCN messages A recovery timer T(r) will be started and all incoming SCN messages
will be queued by the SG. If an ASP becomes active before T(r) expires, will be queued by the SG. If an ASP becomes active before T(r) expires,
the AS will move to AS-ACTIVE state and all the queued messages will be the AS will move to AS-ACTIVE state and all the queued messages will be
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+----------+ Tr Expiry no ASP +-------------+ +----------+ Tr Expiry no ASP +-------------+
in INACT state in INACT state
Tr = Recovery Timer Tr = Recovery Timer
4.3.2 M3UA Management procedures for primitives 4.3.2 M3UA Management procedures for primitives
Before the establishment of an SCTP association the ASP state at both Before the establishment of an SCTP association the ASP state at both
the SG and ASP is assumed to be "Down". the SG and ASP is assumed to be "Down".
As the ASP is responsible for initiating the setup of an SCTP Once the SCTP association is established (See Section 4.1.2) and
association to an SG, the M3UA layer at an ASP receives an M-SCTP assuming that the local M3UA-User is ready, the local ASP M3UA
ESTABLISH request primitive from the Layer Management. the M3UA layer Application Server Process Maintenance (ASPM) function will initiate
will try to establish an SCTP association with the remote M3UA peer at the ASPM procedures, using the ASP-Up/-Down/-Active/-Inactive messages
an SG. Upon reception of an eventual SCTP-Communication Up confirm to convey the ASP-state to the SG - see Section 4.3.3.
primitive from the SCTP, the M3UA layer will invoke the primitive M-
SCTP ESTABLISH confirm to the Layer Management.
The M3UA layers at the SG will receive an SCTP-CommunicationUp
indication primitive from the SCTP when the association is successfully
set up. The M3UA layer will then invoke the primitive M-SCTP ESTABLISH
indication to the Layer Management.
Once the SCTP association is established and assuming that the local
M3UA-User is ready, the local ASP M3UA Application Server Process
Maintenance (ASPM) function will initiate the ASPM procedures, using
the ASP-Up/-Down/-Active/-Inactive messages to convey the ASP-state to
the SG - see Section 4.3.3.
If the M3UA layer subsequently receives an SCTP-Communication Down If the M3UA layer subsequently receives an SCTP-Communication Down
indication from the underlying SCTP layer, it will inform the Layer indication from the underlying SCTP layer, it will inform the Layer
Management by invoking the M-SCTP STATUS indication primitive. The Management by invoking the M-SCTP STATUS indication primitive. The
state of the remote ASP will be moved to "Down". At an ASP, the MTP3- state of the remote ASP will be moved to "Down". At an ASP, the MTP3-
User at an ASP will be informed of the unavailability of any affected User at an ASP will be informed of the unavailability of any affected
SS7 destinations through the use of MTP-PAUSE primitives. In the case SS7 destinations through the use of MTP-PAUSE primitives. In the case
of SS7 network isolation, the local MTP3-Users may be informed by of SS7 network isolation, the local MTP3-Users may be informed by
implementation-dependent means as there is currently no primitive implementation-dependent means as there is currently no primitive
defined for conveying this information. defined for conveying this information.
At an ASP, the Layer Management may try to re-establish the SCTP At an ASP, the Layer Management may try to re-establish the SCTP
association using M-SCTP ESTABLISH request primitive. association using M-SCTP ESTABLISH request primitive.
4.3.3 M3UA Management procedures for peer-to-peer messages 4.3.3 M3UA Management procedures for peer-to-peer messages
All M3UA MGMT and ASP Maintenance messages are sent on a sequenced All M3UA MGMT and ASP Maintenance messages are sent on a sequenced
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At an ASP, the Layer Management may try to re-establish the SCTP At an ASP, the Layer Management may try to re-establish the SCTP
association using M-SCTP ESTABLISH request primitive. association using M-SCTP ESTABLISH request primitive.
4.3.3 M3UA Management procedures for peer-to-peer messages 4.3.3 M3UA Management procedures for peer-to-peer messages
All M3UA MGMT and ASP Maintenance messages are sent on a sequenced All M3UA MGMT and ASP Maintenance messages are sent on a sequenced
stream to ensure ordering. SCTP stream '0' is used. stream to ensure ordering. SCTP stream '0' is used.
4.3.3.1 ASP-Up 4.3.3.1 ASP-Up
After an ASP has successfully established an SCTP association to an SG After an ASP has successfully established an SCTP association to an SG,
or IPSP, the SG or IPSP waits for the ASP to send an ASP-Up message, the SG waits for the ASP to send an ASP-Up message, indicating that the
indicating that the ASP M3UA peer is available. The ASP is always the ASP M3UA peer is available. The ASP is always the initiator of the
initiator of the ASP-Up exchange. This action MAY be initiated at the ASP-Up exchange. This action MAY be initiated at the ASP by an M-ASP
ASP by an M-ASP UP request primitive from Layer Management or may be UP request primitive from Layer Management or may be initiated
initiated automatically by an M3UA management function. automatically by an M3UA management function.
When an ASP-Up message is received at an SG or IPSP and internally the When an ASP-Up message is received at an SG and internally the remote
remote ASP is not considered locked-out for local management reasons, ASP is in the "Down" state and not considered locked-out for local
the SG marks the remote ASP as 'Inactive' and informs Layer Management management reasons, the SG marks the remote ASP as "Inactive" and
with an M-ASP-Up indication primitive. If the SG knows via informs Layer Management with an M-ASP-Up indication primitive. If the
configuration data which Application Servers that the ASP is configured SG knows, via current configuration data, which Application Servers the
to operate in, it can update the ASP status to "Inactive" in each AS ASP is configured to operate in, it can update the ASP status to
pool that it is a member. Alternatively, the SG may move the ASP into "Inactive" in each AS that it is a member. Alternatively, the SG may
a pool of Inactive ASPs available for future activation in AS pool(s) move the ASP into a pool of Inactive ASPs available for future
denoted in the subsequent ASP-Active Routing Contexts. The SG responds activation in Application Server(s) denoted in the subsequent ASP-
with an ASP-Up Ack message in acknowledgement. The SG sends an ASP-Up Active Routing Contexts. The SG responds with an ASP-Up Ack message in
Ack message in response to a received ASP-Up message even if the ASP is acknowledgement. The SG sends an ASP-Up Ack message in response to a
already marked as "Inactive" at the SG. received ASP-Up message even if the ASP is already marked as "Inactive"
at the SG.
If for any local reason (e.g., management lock-out) the SG cannot If for any local reason (e.g., management lock-out) the SG cannot
respond with an ASP-Up Ack, the SG responds to an ASP-Up with an ASP- respond with an ASP-Up Ack, the SG responds to an ASP-Up with an ASP-
Down Ack message with Reason "Management Blocking". Down Ack message with Reason "Management Blocking".
At the ASP, the ASP-Up Ack message received is not acknowledged. Layer At the ASP, the ASP-Up Ack message received is not acknowledged. Layer
Management is informed with an M-ASP UP confirm primitive . Management is informed with an M-ASP UP confirm primitive .
When the Asp sends an ASP-Up it starts timer T(ack). If the ASP does When the ASP sends an ASP-Up message it starts timer T(ack). If the
not receive a response to an ASP-Up within T(ack), the ASP MAY restart ASP does not receive a response to an ASP-Up within T(ack), the ASP MAY
T(ack) and resend ASP-Up messages until it receives an ASP-Up Ack restart T(ack) and resend ASP-Up messages until it receives an ASP-Up
message. T(ack) is provisionable, with a default of 2 seconds. Ack message. T(ack) is provisionable, with a default of 2 seconds.
Alternatively, retransmission of ASP-Up messages may be put under Alternatively, retransmission of ASP-Up messages may be put under
control of Layer Management. In this method, expiry of T(ack) results control of Layer Management. In this method, expiry of T(ack) results
in a M-ASP-Up confirmation carrying a negative indication. in a M-ASP-Up confirmation carrying a negative indication.
The ASP must wait for the ASP-Up Ack message before sending any ASP The ASP must wait for the ASP-Up Ack message before sending any other
messages (e.g., ASPAC). If the remote peer receives any other M3UA M3UA messages (e.g., ASPAC, REG REQ). If the SG receives any other
messages before an ASP Up is received, the remote peer should M3UA messages before an ASP Up is received, the SG should discard them.
discard them.
If an ASP-Up is received and internally the remote ASP is in the
"Active" or "Standby" state, an Error ("Unexpected Message) is returned
and the remote ASP state is not changed.
If an ASP-Up is received and internally the remote ASP is already in
the "Inactive" state, and ASP-Up Ack is returned and no action is
taken.
4.3.3.2 ASP-Down 4.3.3.2 ASP-Down
The ASP will send an ASP-Down to an SG or IPSP when the ASP wishes to The ASP will send an ASP-Down to an SG when the ASP wishes to be
be removed from service in all Application Servers that it is a member removed from service in all Application Servers that it is a member and
And no longer receive any M3UA traffic or management messages. This no longer receive any M3UA traffic or management messages. This action
action MAY be initiated at the ASP by an M-ASP DOWN request primitive MAY be initiated at the ASP by an M-ASP DOWN request primitive from
from Layer Management or may be initiated automatically by an M3UA Layer Management or may be initiated automatically by an M3UA
management function. management function.
Whether the ASP is permanently removed from any AS is a function of Whether the ASP is permanently removed from any AS is a function of
configuration management. configuration management.
The SG marks the ASP as "Down", informs Layer Management with an M-ASP- The SG marks the ASP as "Down", informs Layer Management with an M-ASP-
Up indication primitive, and returns an ASP-Down Ack message to the ASP Down indication primitive, and returns an ASP-Down Ack message to the
if one of the following events occur: ASP if one of the following events occur:
- an ASP-Down message is received from the ASP, - an ASP-Down message is received from the ASP,
- another ASPM message is received from the ASP and the SG has - another ASPM message is received from the ASP and the SG has
locked out the ASP for management reasons. locked out the ASP for management reasons.
The SG sends an ASP-Down Ack message in response to a received ASP-Down The SG sends an ASP-Down Ack message in response to a received ASP-Down
message from the ASP even if the ASP is already marked as "Down" at the message from the ASP even if the ASP is already marked as "Down" at the
SG. SG.
At the ASP, the ASP-Down Ack message received is not acknowledged. At the ASP, the ASP-Down Ack message received is not acknowledged.
Layer Management is informed with an M-ASP Down confirm primitive. Layer Management is informed with an M-ASP Down confirm primitive.
When the Asp sends an ASP-Down it starts timer T(ack). If the ASP does When the ASP sends an ASP-Down it starts timer T(ack). If the ASP does
not receive a response to an ASP-Down within T(ack), the ASP MAY not receive a response to an ASP-Down within T(ack), the ASP MAY
restart T(ack) and resend ASP-Down messages until it receives an restart T(ack) and resend ASP-Down messages until it receives an ASP-
ASP-Down Ack message. T(ack) is provisionable, with a default of 2 Down Ack message. T(ack) is provisionable, with a default of 2
seconds. Alternatively, retransmission of ASP-Down messages may be put seconds. Alternatively, retransmission of ASP-Down messages may be put
under control of Layer Management. In this method, expiry of T(ack) under control of Layer Management. In this method, expiry of T(ack)
results in a M-ASP-Down confirmation carrying a negative indication. results in a M-ASP-Down confirmation carrying a negative indication.
4.3.3.3 M3UA Version Control 4.3.3.3 M3UA Version Control
If an ASP-Up message with an unsupported version is received, the If an ASP-Up message with an unsupported version is received, the
receiving end responds with an Error message, indicating the version receiving end responds with an Error message, indicating the version
the receiving node supports and notifies Layer Management. the receiving node supports and notifies Layer Management.
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4.3.3.4 ASP-Active 4.3.3.4 ASP-Active
Anytime after the ASP has received an ASP-Up Ack from the SG or IPSP, Anytime after the ASP has received an ASP-Up Ack from the SG or IPSP,
the ASP sends an ASP-Active (ASPAC) to the SG indicating that the ASP the ASP sends an ASP-Active (ASPAC) to the SG indicating that the ASP
is ready to start processing traffic. This action MAY be initiated at is ready to start processing traffic. This action MAY be initiated at
the ASP by an M-ASP Active request primitive from Layer Management or the ASP by an M-ASP Active request primitive from Layer Management or
may be initiated automatically by an M3UA management function. In the may be initiated automatically by an M3UA management function. In the
case where an ASP wishes to process the traffic for more than one case where an ASP wishes to process the traffic for more than one
Application Server across a common SCTP association, the ASPAC contains Application Server across a common SCTP association, the ASPAC contains
a list of one or more Routing Contexts to indicate for which a list of one or more Routing Contexts to indicate for which
Application Servers the ASPAC applies. In the case where an ASP-Active Application Servers the ASPAC applies. It is not necessary for the ASP
message does not contain a Routing Context, the receiver must know, via to include all Routing Contexts of interest in the initial ASPAC
configuration data, which AS pools the ASP will be a member. message, thus becoming active in all Routing Contexts at the same time.
Multiple ASPAC messages MAY be used to activate within the Application
Servers independently. In the case where an ASP-Active message does
not contain a Routing Context parameter, the receiver must know, via
configuration data, which Application Server(s) the ASP is a member.
When an ASP Active (ASPAC) message is received, the SG or IPSP responds When an ASP Active (ASPAC) message is received, the SG or IPSP responds
to the ASP with an ASPAC Ack message, acknowledging that the ASPAC was with an ASPAC Ack message(with the same Type value contained in the
received and, depending on the ASPAC Type value received, moves the ASP received APAC), acknowledging that the ASPAC was received and,
to the "Active" or "Standby" state within the associated Application depending on the ASPAC Type value, moves the ASP to the "Active" or
Server(s). Layer Management is informed with an ASP-Active indication "Standby" state within the associated Application Server(s). Layer
primitive. The ASP MUST not send Data messages before receiving an Management is informed with an ASP-Active indication primitive. If the
ASPAC Ack. If the SG or IPSP receives any Data messages before an SG or IPSP receives any Data messages before an ASPAC is received, the
ASPAC is received, the SG or IPSP should discard them. SG or IPSP should discard them. By sending an ASPAC Ack, the SG or
IPSP is now ready to receive and send traffic for the related Routing
Contexts. The ASP MUST not send Data messages before receiving an
ASPAC Ack.
The SG sends an ASP-Active Ack message in response to a received ASP- Multiple ASPAC Ack messages MAY be used in response to an ASPAC
Active message from the ASP even if the ASP is already marked as containing multiple Routing Contexts, allowing the SG or IPSP to
independently Ack for different (sets of) Routing Contexts. The SG or
IPSP sends an Error ("Invalid Routing Context") message for each
invalid or un-configured Routing Context value in a received ASPAC
message.
The SG MUST send an ASP-Active Ack message in response to a received
ASP-Active message from the ASP and the ASP is already marked as
"Active" at the SG. "Active" at the SG.
At the ASP, the ASP-Active Ack message received is not acknowledged. At the ASP, the ASP-Active Ack message received is not acknowledged.
Layer Management is informed with an M-ASP Active confirm primitive. Layer Management is informed with an M-ASP Active confirm primitive.
When the ASP sends an ASP-Active it starts timer T(ack). If When the ASP sends an ASP-Active it starts timer T(ack). If the ASP
the ASP does not receive a response to an ASP-Active within T(ack), the does not receive a response to an ASP-Active within T(ack), the ASP MAY
ASP MAY restart T(ack) and resend ASP-Active messages until it restart T(ack) and resend ASP-Active messages until it receives an ASP-
receives an ASP-Active Ack message. T(ack) is provisionable, with a Active Ack message. T(ack) is provisionable, with a default of 2
default of 2 seconds. Alternatively, retransmission of ASP-Active seconds. Alternatively, retransmission of ASP-Active messages may be
messages may be put under control of Layer Management. In this method, put under control of Layer Management. In this method, expiry of
expiry of T(ack) results in a M-ASP-Active confirmation carrying a T(ack) results in a M-ASP-Active confirmation carrying a negative
negative indication. indication.
There are two modes of Application Server traffic handling in the SG There are four modes of Application Server traffic handling in the SG
M3UA - Over-ride and Load-share. The Type parameter in the ASPAC M3UA - Over-ride, Over-ride (Standby), Loadshare and Load-share
message indicates the traffic handling mode used in a particular (Standby). The Traffic Mode Type parameter in the ASPAC message
Application Server. If the SG determines that the mode indicated in an indicates the traffic handling mode used in a particular Application
ASPAC is incompatible with the mode currently used in the AS, the SG Server. If the SG determines that the mode indicated in an ASPAC is
responds with an Error message indicating "Invalid Traffic Handling unsupported or incompatible with the mode currently configured for the
Mode". AS, the SG responds with an Error message indicating "Unsupported /
Invalid Traffic Handling Mode". If the Traffic Handling mode of the
Application Server is not already known via configuration data, then
the Traffic handling mode indicated in the first ASPAC message causing
the transition of the Application Server state to "Active" MAY be used
to set the mode.
In the case of an Over-ride mode AS, reception of an ASPAC message at In the case of an Over-ride mode AS, reception of an ASPAC message at
an SG causes the redirection of all traffic for the AS to the ASP that an SG causes the redirection of all traffic for the AS to the ASP that
sent the ASPAC. Any previously active ASP in the AS is now considered sent the ASPAC. Any previously active ASP in the AS is now considered
Inactive and will no longer receive traffic from the SG within the AS. Inactive and will no longer receive traffic from the SG within the AS.
The SG or IPSP sends a Notify (Alternate ASP-Active) to the previously The SG or IPSP sends a Notify (Alternate ASP-Active) to the previously
active ASP in the AS, after stopping all traffic to that ASP. In the active ASP in the AS, after stopping all traffic to that ASP.
case of Over-ride (Standby) mode the actions are the same with the
exception that the traffic is not started to the ASP until the In the case of Over-ride (Standby) mode the traffic is not started to
previously active ASP transitions to "Inactive or "Down" state. At the ASP until the previously active ASP transitions to "Inactive or
this point the ASP that sent the Over-Ride (Standby) ASPAC is moved to "Down" state. At this point the ASP that sent the Over-Ride (Standby)
the Active state and the traffic is redirected. A Notify message is ASPAC is moved to the Active state and the traffic is redirected. A
not sent in this case. second ASP-Active Ack message with a new Traffic Mode Type ("Over-
ride", previously "Over-ride(Standby)") is sent to the ASP. A Notify
(Alternate ASP-Active) message is not sent in this case.
In the case of a Load-share mode AS, reception of an ASPAC message at In the case of a Load-share mode AS, reception of an ASPAC message at
an SG or IPSP causes the direction of traffic to the ASP sending the an SG or IPSP causes the direction of traffic to the ASP sending the
ASPAC, in addition to all the other ASPs that are currently active in ASPAC, in addition to all the other ASPs that are currently active in
the AS. The algorithm at the SG for load-sharing traffic within an AS the AS. The algorithm at the SG for load-sharing traffic within an AS
to all the active ASPs is implementation dependent. The algorithm to all the active ASPs is implementation dependent. The algorithm
could, for example be round-robin or based on information in the Data could, for example be round-robin or based on information in the Data
message (e.g., such as the SLS, SCCP SSN, ISUP CIC value). message (e.g., such as the SLS, SCCP SSN, ISUP CIC value).
In the case of Load-share (Standby) mode, the actions are the same with An SG or IPSP, upon reception of an ASPAC for the first ASP in a
the exception that the traffic is not started to the ASP until the SG Loadshare AS, MAY choose not to direct traffic to a newly active ASP
or IPSP determines that there are insufficient resources available in until it determines that there are sufficient resources to handle the
the AS. This is likely due to one of the active load-sharing ASPs expected load (e.g., until there are sufficient ASPs "Active" in the
transitions to the "Inactive" or "Down" state. At this point the ASP AS).
that sent the Load-share (Standby) ASPAC s moved to the Active state
and traffic is started. A Notify message is not sent in this case. In the case of Load-share (Standby) mode, the traffic is not started to
the ASP until the SG or IPSP determines that there are insufficient
resources available in the AS. This is likely when one of the active
load-sharing ASPs transitions to the "Inactive" or "Down" state. At
this point the ASP that sent the Load-share (Standby) ASPAC is moved to
the Active state and traffic is started. A second ASP-Active Ack
message with a new Traffic Mode Type ("Load-share" - previously
"Loadshare(Standby)") is sent to the ASP. A Notify ("Insufficient ASP
resources active in AS ") message is not sent in this case.
All ASPs within a load-sharing mode AS must be able to handle any All ASPs within a load-sharing mode AS must be able to handle any
traffic within the AS, in order to accommodate any potential fail-over traffic within the AS, in order to accommodate any potential fail-over
or rebalancing of the offered load. or rebalancing of the offered load.
A node that receives an ASPAC with an incorrect Type for a particular
Routing Context will respond with an Error Message (Cause: Invalid
Traffic Handling Mode). A node that receives an unknown Routing
Context value responds with an Error message (Cause: Invalid Routing
Context).
4.3.3.5 ASP Inactive 4.3.3.5 ASP Inactive
When an ASP wishes to withdraw from receiving traffic within an AS, the When an ASP wishes to withdraw from receiving traffic within an AS, the
ASP sends an ASP Inactive (ASPIA) to the SG or IPSP. This action MAY ASP sends an ASP Inactive (ASPIA) to the SG or IPSP. This action MAY
be initiated at the ASP by an M-ASP INACTIVE request primitive from be initiated at the ASP by an M-ASP INACTIVE request primitive from
Layer Management or may be initiated automatically by an M3UA Layer Management or may be initiated automatically by an M3UA
management function. In the case where an ASP is processing the management function. In the case where an ASP is processing the
traffic for more than one Application Server across a common SCTP traffic for more than one Application Server across a common SCTP
association, the ASPIA contains one or more Routing Contexts to association, the ASPIA contains one or more Routing Contexts to
indicate for which Application Servers the ASPIA applies. In the case indicate for which Application Servers the ASPIA applies. In the case
where an ASP-Inactive message does not contain a Routing Context, the where an ASP-Inactive message does not contain a Routing Context
receiver must know via configuration data which AS pools the ASP is a parameter, the receiver must know, via configuration data, which
member and move the ASP to the "Inactive" state in each AS. Application Servers the ASP is a member and move the ASP to the
"Inactive" state in each AS.
There are two modes of Application Server traffic handling in the SG or
IPSP M3UA when withdrawing an ASP from service - Over-ride and Load-
share. The Type parameter in the ASPIA message indicates the mode used
in a particular Application Server. If the SG or IPSP determines that
the mode indicates in an ASPIA is inconsistent with the traffic
handling mode currently used in the AS, a this is reported to local
management indicating("Invalid Traffic Handling Mode"). The ASPIA is
still processed.
In the case of an Over-ride mode AS, where another ASP has already In the case of an Over-ride mode AS, where another ASP has already
taken over the traffic within the AS with an Over-ride ASPAC, the ASP taken over the traffic within the AS with an Over-ride ASPAC, the ASP
that sends the ASPIA is already considered by the SG to be "Inactive". that sends the ASPIA is already considered by the SG to be "Inactive".
An ASPIA Ack message is sent to the ASP, after ensuring that all An ASPIA Ack message is sent to the ASP, after ensuring that all
traffic is stopped to the ASP. traffic is stopped to the ASP.
In the case of a Load-share mode AS, the SG moves the ASP to the In the case of a Load-share mode AS, the SG moves the ASP to the
"Inactive" state and the AS traffic is re-allocated across the "Inactive" state and the AS traffic is re-allocated across the
remaining "active" ASPs per the load-sharing algorithm currently used remaining "active" ASPs per the load-sharing algorithm currently used
within the AS. A NTFY(Insufficient ASP resources active in AS) may be
sent to all inactive ASPs, if required. However, if a Loadshare
within the AS. A NTFY(Insufficient ASPs) may be sent to all inactive (Standby) ASP is available, it may be now immediately included in the
ASPs, if required. However, if a Loadshare (Standby) ASP is available, loadshare group and a Notify message is not sent. An ASPIA Ack message
it may be now immediately included in the loadshare group and a Notify is sent to the ASP after all traffic is halted and Layer Management is
message is not sent. An ASPIA Ack message is sent to the ASP after all informed with an ASP-INACTIVE indication primitive.
traffic is halted and Layer Management is informed with an ASP-INACTIVE
indication primitive. Multiple ASPIA Ack messages MAY be used in response to an ASPIA
containing multiple Routing Contexts, allowing the SG or IPSP to
independently Ack for different (sets of) Routing Contexts. The SG or
IPSP sends an Error ("Invalid Routing Context") message for each
invalid or un-configured Routing Context value in a received ASPIA
message.
The SG MUST send an ASP-Inactive Ack message in response to a received
ASP-Inactive message from the ASP and the ASP is already marked as
"Inactive" at the SG.
At the ASP, the ASP-INACTIVE Ack message received is not acknowledged. At the ASP, the ASP-INACTIVE Ack message received is not acknowledged.
Layer Management is informed with an M-ASP INACTIVE confirm primitive. Layer Management is informed with an M-ASP INACTIVE confirm primitive.
When the ASP sends an ASP-Inactive it starts timer T(ack). If the ASP When the ASP sends an ASP-Inactive it starts timer T(ack). If the ASP
does not receive a response to an ASP-Inactive within T(ack), the ASP does not receive a response to an ASP-Inactive within T(ack), the ASP
MAY restart T(ack) and resend ASP-Inactive messages until it receives MAY restart T(ack) and resend ASP-Inactive messages until it receives
an ASP-Inactive Ack message. T(ack) is provisionable, with a default an ASP-Inactive Ack message. T(ack) is provisionable, with a default
of 2 seconds. Alternatively, retransmission of ASP-Inactive messages of 2 seconds. Alternatively, retransmission of ASP-Inactive messages
may be put under control of Layer Management. In this method, expiry may be put under control of Layer Management. In this method, expiry
of T(ack) results in a M-ASP-Inactive confirmation carrying a negative of T(ack) results in a M-ASP-Inactive confirmation carrying a negative
indication. indication.
If no other ASPs are "Active" or "Standby" in the Application Server, If no other ASPs are "Active" or "Standby" in the Application Server,
the SG sends a NTFY(AS-Pending) to all inactive ASPs of the AS and the SG sends a NTFY(AS-Pending) to all inactive ASPs of the AS and
either discards all incoming messages for the AS or starts buffering either discards all incoming messages for the AS or starts buffering
the incoming messages for T(r)seconds, after which messages will be the incoming messages for T(r)seconds, after which messages will be
discarded. T(r) is configurable by the network operator. If the SG discarded. T(r) is configurable by the network operator. If the SG
receives an ASPAC from an ASP in the AS before expiry of T(r), the receives an ASPAC from an ASP in the AS before expiry of T(r), the
buffered traffic is directed to the ASP and the timer is cancelled. If buffered traffic is directed to the ASP and the timer is cancelled. If
T(r) expires, the AS is moved to the "Down" state. T(r) expires, the AS is moved to the "Inactive" state.
4.3.3.6 Notify 4.3.3.6 Notify
A Notify message reflecting a change in the AS state is sent to all A Notify message reflecting a change in the AS state is sent to all
ASPs in the AS, except those in the "Down" state, with appropriate ASPs in the AS, except those in the "Down" state, with appropriate
Status Identification. At the ASP, Layer Management is informed with Status Identification. At the ASP, Layer Management is informed with
an M-NOTIFY indication primitive. an M-NOTIFY indication primitive.
In the case where a Notify (AS-Pending) message is sent by an SG that In the case where a Notify (AS-Pending) message is sent by an SG that
now has no ASPs active to service the traffic, or a NTFY(Insufficient now has no ASPs active to service the traffic, or a NTFY(Insufficient
ASPs) is sent in the Loadshare mode, the Notify does not explicitly ASP resources active in AS) is sent in the Loadshare mode, the Notify
force the ASP(s) receiving the message to become active. The ASPs does not explicitly compel the ASP(s) receiving the message to become
remain in control of what (and when) action is taken. active. The ASPs remain in control of what (and when) traffic action is
taken.
4.3.3.7 Heartbeat 4.3.3.7 Heartbeat
The optional Heartbeat procedures may be used when operating over The optional Heartbeat procedures may be used when operating over
transport layers that do not have their own heartbeat mechanism for transport layers that do not have their own heartbeat mechanism for
detecting loss of the transport association (i.e., other than the detecting loss of the transport association (i.e., other than the
SCTP). SCTP).
After receiving an ASP-Up Ack message from an M3UA peer in response to After receiving an ASP-Up Ack message from an M3UA peer in response to
an ASP-Up message, an ASP may optionally send Beat messages an ASP-Up message, an ASP may optionally send Beat messages
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message MAY choose to consider the remote ASP as unavailable. The message MAY choose to consider the remote ASP as unavailable. The
contents/format of the Heartbeat Data parameter is implementation- contents/format of the Heartbeat Data parameter is implementation-
dependent and only of local interest to the original sender. The dependent and only of local interest to the original sender. The
contents may be used, for example, to support a Heartbeat sequence contents may be used, for example, to support a Heartbeat sequence
algorithm (to detect missing Heartbeats), and/or a timestamp mechanism algorithm (to detect missing Heartbeats), and/or a timestamp mechanism
(to evaluate delays). (to evaluate delays).
Note: Heartbeat related events are not shown in Figure 4 "ASP state Note: Heartbeat related events are not shown in Figure 4 "ASP state
transition diagram". transition diagram".
4.3.4 Routing Key Management procedures
4.3.4.1 Registration
An ASP MAY dynamically register with an SG as an ASP within an
Application Server using the REG REQ message. A Routing Key parameter
in the REG REQ specifies the parameters associated with the Routing
Key.
The SG examines the contents of the received Routing Key parameter and
compares it with the currently provisioned Routing Keys. If the
received Routing Key matches an existing SG Routing Key entry, and the
ASP is not currently included in the list of ASPs for the related
Application Server, the ASP MAY authorize the ASP to be added to the
AS. Or, if the Routing Key does not currently exist and the received
Routing Key data is valid and unique, an SG supporting dynamic
configuration MAY authorize the creation of a new Routing Key and
related Application Server and add the ASP to the new AS. In either
case, the SG returns a Registration Response message to the ASP,
containing the same Local-RK-Identifier as provided in the initial
request, and a Registration Result "Successfully Registered". A unique
Routing Context value assigned to the SG Routing Key is included. The
method of Routing Context value assignment at the SG/SGP is
implementation dependent but must be guaranteed to be unique across all
SGPs in an SG.
If the SG determines that the received Routing Key data is invalid, or
contains invalid parameter values, the SG returns a Registration
Response message to the ASP, containing a Registration Result "Error -
Invalid Routing Key", "Error - Invalid DPC, "Error - Invalid Network
Appearance" as appropriate.
If the SG determines that the Routing Key parameter overlaps with an
existing Routing Key entry, the SG returns a Registration Response
message to the ASP, with a Registration Status of "Error - Overlapping
(Non-Unique) Routing Key". An incoming signalling message received at
an SG cannot match against more than one Routing Key.
If the SG does not authorize the registration request, the SG returns a
REG RSP message to the ASP containing the Registration Result "Error
Permission Denied".
If an SG determines that a received Routing Key does not currently
exist and the SG does not support dynamic configuration, the SG returns
a Registration Response message to the ASP, containing a Registration
Result "Error - Routing Key not Provisioned".
If an SG determines that a received Routing Key does not currently
exist and the SG supports dynamic configuration but does not have the
capacity to add new Routing Key and Application Server entries, the SG
returns a Registration Response message to the ASP, containing a
Registration Result "Error - Insufficient Resources".
An ASP MAY register multiple Routing Keys at once by including a number
of Routing Key parameters in a single REG REQ message. The SG MAY
respond to each registration request in a single REG RSP message,
indicating the success or failure result for each Routing Key in a
separate Registration Result parameter. Alternatively the SG MAY
respond with multiple REG RSP messages, each with one or more
Registration Result parameters. The ASP uses the Local-RK-Identifier
parameter to correlate the requests with the responses.
Upon successful registration of an ASP in an AS, the SG can now send
related SSNM messaging, if this did not previously start upon the ASP
transitioning to "Inactive".
4.3.4.2 Deregistration
An ASP MAY dynamically deregister with an SG as an ASP within an
Application Server using the DEREG REQ message. A Routing Context
parameter in the DEREG REQ specifies which Routing Key to de-register.
The SG examines the contents of the received Routing Context parameter
and validates that the ASP is currently registered in the Application
Server(s) related to the included Routing Context(s). If validated,
the ASP is de-registered as an ASP in the related Application Server.
The deregistration procedure does not necessarily imply the deletion of
Routing Key and Application Server configuration data at the SG. Other
ASPs may continue to be associated with the Application Server, in
which case the Routing Key data CANNOT be deleted. If a Deregistration
results in no more ASPs in an Application Server, an SG MAY delete the
Routing Key data.
The SG acknowledges the de-registration request by returning a DEREG
RSP to the requesting ASP. The result of the de-registration is found
in the Deregistration Result parameter, indicating success or failure
with cause.
An ASP MAY deregister multiple Routing Contexts at once by including a
number of Routing Contexts in a single DEREG REQ message. The SG MUST
respond to each deregistration request in a single DEREG RSP message,
indicating the success or failure result for each Routing Context in a
separate Deregistration Result parameter.
4.4 Procedures to support the M3UA services 4.4 Procedures to support the M3UA services
4.4.1 At an SG 4.4.1 At an SG
On receiving an MTP-PAUSE, MTP-RESUME, or MTP-STATUS indication On receiving an MTP-PAUSE, MTP-RESUME, or MTP-STATUS indication
primitive from the nodal inter-working function at an SG, the SG M3UA primitive from the nodal inter-working function at an SG, the SG M3UA
layer will send a corresponding SSNM DUNA, DAVA, SCON, or DUPU message layer will send a corresponding SSNM DUNA, DAVA, SCON, or DUPU message
(see Section 2) to the M3UA peers at concerned ASPs. The M3UA layer (see Section 2) to the M3UA peers at concerned ASPs. The M3UA layer
must fill in various fields of the SSNM messages consistently with the must fill in various fields of the SSNM messages consistently with the
information received in the primitives. information received in the primitives.
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up appropriate indications n the primitives to the M3UA User, as though up appropriate indications n the primitives to the M3UA User, as though
equivalent SSNM messages were received. For example, the loss of an equivalent SSNM messages were received. For example, the loss of an
SCTP association to an SG may cause the unavailability of a set of SS7 SCTP association to an SG may cause the unavailability of a set of SS7
destinations. MTP-Pause indications to the M3UA User is appropriate. destinations. MTP-Pause indications to the M3UA User is appropriate.
To accomplish this, the M3UA layer at an ASP maintains the status of To accomplish this, the M3UA layer at an ASP maintains the status of
routes via the SG, much like an MTP3 layer maintains route-set status. routes via the SG, much like an MTP3 layer maintains route-set status.
4.4.2.2 Multiple SG configurations 4.4.2.2 Multiple SG configurations
At an ASP, upon receiving an SSNM message from the remote M3UA Peer, At an ASP, upon receiving an SSNM message from the remote M3UA Peer,
the the M3UA layer updates the status of the affected route(s) via the
M3UA layer updates the status of the affected route(s) via the
originating SG and determines, whether or not the overall availability originating SG and determines, whether or not the overall availability
or congestion status of the effected destination(s) has changed. In or congestion status of the effected destination(s) has changed. In
this case the M3UA layer invokes the appropriate primitive indications this case the M3UA layer invokes the appropriate primitive indications
to the resident M3UA-Users. Local management is informed. to the resident M3UA-Users. Local management is informed.
4.4.3 ASP Auditing 4.4.3 ASP Auditing
An ASP may optionally initiate an audit procedure in order to enquire An ASP may optionally initiate an audit procedure in order to enquire
of an SG the availability and, if the congestion method with multiple of an SG the availability and, if the congestion method with multiple
congestion levels and message priorities is used, congestion status of congestion levels and message priorities is used, congestion status of
skipping to change at page 67, line 9 skipping to change at page 81, line 9
subsequent reception of an SCON implies that the Affected Destination subsequent reception of an SCON implies that the Affected Destination
is available. The reception of a DAVA implies that the routeset to the is available. The reception of a DAVA implies that the routeset to the
Affected Destination is not congested. Obviously with the reception of Affected Destination is not congested. Obviously with the reception of
an DUNA, the routeset to the Affected Destination can not also be an DUNA, the routeset to the Affected Destination can not also be
congested. congested.
5.0 Examples of M3UA Procedures 5.0 Examples of M3UA Procedures
5.1 Establishment of Association and Traffic between SGs and ASPs 5.1 Establishment of Association and Traffic between SGs and ASPs
5.1.1 Single ASP in an Application Server ("1+0" sparing) 5.1.1a Single ASP in an Application Server ("1+0" sparing), No
Registration
This scenario shows the example M3UA message flows for the This scenario shows the example M3UA message flows for the
establishment of traffic between an SG and an ASP, where only one ASP establishment of traffic between an SG and an ASP, where only one ASP
is configured within an AS (no backup). It is assumed that the SCTP is configured within an AS (no backup). It is assumed that the SCTP
association is already set-up. The sending of DUNA/SCON messages by the association is already set-up. The sending of DUNA/SCON messages by the
SG is not shown but would be similar to 5.1.2. SG is not shown but would be similar to 5.1.2.
SG ASP1 SG ASP1
|
|<---------ASP Up----------|
|-------ASP-Up Ack-------->|
| | | |
|<-------ASP Active--------| |<-------------ASP Up------------|
|-----ASP Active Ack------>| |-----------ASP-Up Ack---------->|
| |
|<------- ASP Active(RCn)--------| RC: Routing Context
|-----ASP Active Ack (RCn)------>| (optional)
| |
Note: If ASPAC contains an optional Routing Context parameter, The
ASPAC only applies for the specified RC value. For an unknown RC value,
the SG responds with an Error message.
5.1.1b Single ASP in Application Server ("1+0" sparing), With Dynamic
Registration
This scenario is the same as for 5.1.1a but with the optional exchange
of registration information. In this case the Registration is accepted
by the SG.
SG ASP1
| |
|<------------ASP Up-------------|
|----------ASP-Up Ack----------->|
| |
|<----REGISTER REQ(LRCn,RKn)-----| LRC: Local Routing
| | Context
|----REGISTER RESP(LRCn,RCn)---->| RK: Routing Key
| | RC: Routing Context
| |
|<------- ASP Active(RCn)--------|
|-----ASP Active Ack (RCn)------>|
| |
Note: In the case of an unsuccessful registration attempt (e.g.,
Invalid RKn), the Register Response will contain an unsuccessful
indication and the ASP will not subsequently send an ASPAC.
5.1.1c Single ASP in multiple Application Servers (each with "1+0"
sparing), With Dynamic Registration (Case 1 Multiple Registration
Requests)
SG ASP1
| |
|<------------ASP Up-------------|
|----------ASP-Up Ack----------->|
| |
|<----REGISTER REQ(LRC1,RK1)-----| LRC: Local Routing
| | Context
|----REGISTER RESP(LRC1,RC1)---->| RK: Routing Key
| | RC: Routing Context
| |
|<------- ASP Active(RC1)--------|
|-----ASP Active Ack (RC1)------>|
| |
: :
: :
| |
|<----REGISTER REQ(LRCn,RKn)-----|
| |
|----REGISTER RESP(LRCn,RCn)---->|
| |
| |
|<------- ASP Active(RCn)--------|
|-----ASP Active Ack (RCn)------>|
| |
Note: In the case of an unsuccessful registration attempt (e.g.,
Invalid RKn), the Register Response will contain an unsuccessful
indication and the ASP will not subsequently send an ASPAC. Each LRC/RK
pair registration is considered independently.
It is not necessary to follow a Registration Request/Response with an
ASP Active before sending the next Registration Request. The ASP Active
can happen any time after the related successful Registration.
5.1.1.d Single ASP in multiple Application Servers (each with "1+0"
sparing), With Dynamic Registration (Case 2 Single Registration
Request)
SG ASP1
| |
|<------------ASP Up-------------|
|----------ASP-Up Ack----------->|
| |
|<---REGISTER REQ({LRC1,RK1},----|
| ..., |
| {LRCn,RKn}),----|
| |
|---REGISTER RESP({LRC1,RC1},--->|
| ..., |
| (LRCn,RCn}) |
| |
|<------- ASP Active(RC1)--------|
|-----ASP Active Ack (RC1)------>|
| | | |
: :
: :
| |
|<------- ASP Active(RCn)--------|
|-----ASP Active Ack (RCn)------>|
| |
Note: In the case of an unsuccessful registration attempt (e.g.,
Invalid RKn), the Register Response will contain an unsuccessful
indication and the ASP will not subsequently send an ASPAC. Each LRC/RK
pair registration is considered independently.
The ASP Active can happen any time after the related successful
Registration, and may have more than one RC.
5.1.2 Two ASPs in Application Server ("1+1" sparing) 5.1.2 Two ASPs in Application Server ("1+1" sparing)
This scenario shows the example M3UA message flows for the This scenario shows the example M3UA message flows for the
establishment of traffic between an SG and two ASPs in the same establishment of traffic between an SG and two ASPs in the same
Application Server, where ASP1 is configured to be "active" and ASP2 a Application Server, where ASP1 is configured to be "active" and ASP2 a
"standby" in the event of communication failure or the withdrawal from "standby" in the event of communication failure or the withdrawal from
service of ASP1. ASP2 may act as a hot, warm, or cold standby service of ASP1. ASP2 may act as a hot, warm, or cold standby
depending on the extent to which ASP1 and ASP2 share call/transaction depending on the extent to which ASP1 and ASP2 share call/transaction
state or can communicate call state under failure/withdrawal events. state or can communicate call state under failure/withdrawal events.
skipping to change at page 69, line 28 skipping to change at page 86, line 9
|----ASP-Act Ack---->| | | |----ASP-Act Ack---->| | |
| | | | | | | |
|<--------------------ASP Act. (Ldshr)---| | |<--------------------ASP Act. (Ldshr)---| |
|-----------------------ASP-Act Ack----->| | |-----------------------ASP-Act Ack----->| |
| | | | | | | |
5.2 ASP Traffic Fail-over Examples 5.2 ASP Traffic Fail-over Examples
5.2.1 (1+1 Sparing, withdrawal of ASP, Back-up Over-ride) 5.2.1 (1+1 Sparing, withdrawal of ASP, Back-up Over-ride)
Following on from the example in Section 4.1.2, and ASP withdraws from Following on from the example in Section 5.1.2, and ASP1 withdraws from
service: service:
SG ASP1 ASP2 SG ASP1 ASP2
| | | | | |
|<-----ASP Inactive-------| | |<-----ASP Inactive-------| |
|----ASP Inactive Ack---->| | |----ASP Inactive Ack---->| |
|------------------------NTFY(AS-Inact.)(Optional)-->| |------------------------NTFY(AS-Pending)----------->|
| | | | | |
|<------------------------------ ASP Active----------| |<------------------------------ ASP Active----------|
|------------------------------ASP-Active Ack)------>| |------------------------------ASP-Active Ack)------>|
| | | |
Note: If the SG detects loss of the M3UA peer (M3UA heartbeat loss or Note: If the SG detects loss of the M3UA peer (M3UA heartbeat loss or
detection of SCTP failure), the initial SG-ASP1 ASP Inactive message detection of SCTP failure), the initial SG-ASP1 ASP Inactive message
exchange would not occur. exchange would not occur.
5.2.2 (1+1 Sparing, Back-up Over-ride) 5.2.2 (1+1 Sparing, Back-up Over-ride)
Following on from the example in Section 4.1.2, and ASP2 wishes to Following on from the example in Section 5.1.2, and ASP2 wishes to
over-ride ASP1 and take over the traffic: over-ride ASP1 and take over the traffic:
SG ASP1 ASP2 SG ASP1 ASP2
| | | | | |
|<------------------------------ ASP Active----------| |<------------------------------ ASP Active----------|
|-------------------------------ASP-Active Ack------>| |-------------------------------ASP-Active Ack------>|
|----NTFY(Alt ASP-Act)--->| |----NTFY(Alt ASP-Act)--->|
| | | | | |
5.2.3 (n+k Sparing, Load-sharing case, withdrawal of ASP) 5.2.3 (n+k Sparing, Load-sharing case, withdrawal of ASP)
Following on from the example in Section 4.1.4, and ASP1 withdraws from Following on from the example in Section 5.1.4, and ASP1 withdraws from
service: service:
SG ASP1 ASP2 ASP3 SG ASP1 ASP2 ASP3
| | | | | | | |
|<----ASP Inact.-----| | | |<----ASP Inact.-----| | |
|---ASP-Inact Ack--->| | | |---ASP-Inact Ack--->| | |
| | | | | | | |
|---------------------------------NTFY(Ins. ASPs)(Optional)->| |---------------------------------NTFY(Ins. ASPs)----------->|
| | | | | | | |
|<-----------------------------------------ASP Act (Ldshr)---| |<-----------------------------------------ASP Act (Ldshr)---|
|-------------------------------------------ASP Act (Ack)--->| |-------------------------------------------ASP Act (Ack)--->|
| | | | | | | |
The Notify message to ASP3 is optional, as well as the ASP-Active from For the Notify to occur the SG maintains knowledge of the minimum ASP
ASP3. The optional Notify can only occur if the SG maintains knowledge resources required - for example if the SG knows that "n+k" = "2+1" for
of the minimum ASP resources required - for example if the SG knows a load-share AS and "n" currently equals "1".
that "n+k" = "2+1" for a load-share AS and "n" currently equals "1".
Note: If the SG detects loss of the ASP1 M3UA peer (M3UA heartbeat loss Note: If the SG detects loss of the ASP1 M3UA peer (M3UA heartbeat loss
or detection of SCTP failure), the first SG-ASP1 ASP Inactive message or detection of SCTP failure), the first SG-ASP1 ASP Inactive message
exchange would not occur. exchange would not occur.
5.3 M3UA/MTP3-User Boundary Examples 5.3 M3UA/MTP3-User Boundary Examples
5.3.1 At an ASP 5.3.1 At an ASP
This section describes the primitive mapping from the MTP3 User to M3UA This section describes the primitive mapping from the MTP3 User to M3UA
skipping to change at page 71, line 50 skipping to change at page 88, line 16
- Map the Payload of a Data message into the MTP-Transfer Indication - Map the Payload of a Data message into the MTP-Transfer Indication
primitive primitive
- Pass the MTP-Transfer Indication primitive to the user part. In - Pass the MTP-Transfer Indication primitive to the user part. In
case of multiple user parts, the optional fields of the Data case of multiple user parts, the optional fields of the Data
message are used to determine the concerned user part. message are used to determine the concerned user part.
SG ASP SG ASP
| | | |
|------Data Message------>|---MTP-Transfer ind. |------Data Message------>|-->MTP-Transfer ind.
| | | |
5.3.1.1.3 Support for ASP Querying of SS7 Destination States 5.3.1.1.3 Support for ASP Querying of SS7 Destination States
There are situations such as temporary loss of connectivity to the SG There are situations such as temporary loss of connectivity to the SG
that may cause the M3UA on the ASP to audit SS7 destination that may cause the M3UA on the ASP to audit SS7 destination
availability states. Note: there is no primitive for the MTP3-User to availability states. Note: there is no primitive for the MTP3-User to
request this audit from the M3UA as this is initiated by an internal request this audit from the M3UA as this is initiated by an internal
M3UA management function. M3UA management function.
skipping to change at page 75, line 30 skipping to change at page 91, line 41
* Improper Monopolization of Services * Improper Monopolization of Services
When M3UA is running in professionally managed corporate or service When M3UA is running in professionally managed corporate or service
provider network, it is reasonable to expect that this network includes provider network, it is reasonable to expect that this network includes
an appropriate security policy framework. The "Site Security Handbook" an appropriate security policy framework. The "Site Security Handbook"
[21] should be consulted for guidance. [21] should be consulted for guidance.
When the network in which M3UA runs in involves more than one party, it When the network in which M3UA runs in involves more than one party, it
may not be reasonable to expect that all parties have implemented may not be reasonable to expect that all parties have implemented
security in a sufficient manner. In such a case, it is recommended security in a sufficient manner. In such a case, it is recommended
that that IPSEC is used to ensure confidentiality of user payload. Consult
[22] for more information on configuring IPSEC services.
IPSEC is used to ensure confidentiality of user payload. Consult [22]
for more information on configuring IPSEC services.
6.3 Protecting Confidentiality 6.3 Protecting Confidentiality
Particularly for mobile users, the requirement for confidentiality may Particularly for mobile users, the requirement for confidentiality may
include the masking of IP addresses and ports. In this case include the masking of IP addresses and ports. In this case
application level encryption is not sufficient; IPSEC ESP should be application level encryption is not sufficient; IPSEC ESP should be
used instead. Regardless of which level performs the encryption, the used instead. Regardless of which level performs the encryption, the
IPSEC ISAKMP service should be used for key management. IPSEC ISAKMP service should be used for key management.
7.0 IANA Considerations 7.0 IANA Considerations
skipping to change at page 77, line 24 skipping to change at page 93, line 33
(c) Detailed definition of each component of the parameter value. (c) Detailed definition of each component of the parameter value.
(d) Detailed description of the intended use of this parameter type, (d) Detailed description of the intended use of this parameter type,
and an indication of whether and under what circumstances multiple and an indication of whether and under what circumstances multiple
instances of this parameter type may be found within the same instances of this parameter type may be found within the same
message. message.
8.0 Acknowledgements 8.0 Acknowledgements
The authors would like to thank John Loughney, Neil Olson, Michael The authors would like to thank John Loughney, Neil Olson, Michael
Tuexen, Nikhil Jain, Steve Lorusso, Dan Brendes, Joe Keller, Heinz Tuexen, Nikhil Jain, Steve Lorusso, Dan Brendes, Joe Keller, Heinz
Prantner, Barry Nagelberg, Naoto Makinae for their valuable comments Prantner, Barry Nagelberg, Naoto Makinae, Selvam Rengasami, Shyamal
and suggestions. Prasad, Joyce Archibald, Ray Singh, Antonio Roque Alvarez and many
others for their valuable comments and suggestions.
9.0 References 9.0 References
[1] RFC 2719, "Framework Architecture for Signaling Transport" [1] RFC 2719, "Framework Architecture for Signaling Transport"
[2] ITU-T Recommendations Q.761 to Q.767, 'Signalling System No.7 (SS7) [2] ITU-T Recommendations Q.761 to Q.767, 'Signalling System No.7 (SS7)
- ISDN User Part (ISUP)' - ISDN User Part (ISUP)'
[3] ANSI T1.113 - 'Signaling System Number 7 - ISDN User Part [3] ANSI T1.113 - 'Signaling System Number 7 - ISDN User Part
skipping to change at page 78, line 20 skipping to change at page 94, line 30
[11] ETSI ETS 300 287-1, "Integrated Services Digital Network (ISDN); [11] ETSI ETS 300 287-1, "Integrated Services Digital Network (ISDN);
Signalling System No.7; Transaction Capabilities (TC) version 2; Signalling System No.7; Transaction Capabilities (TC) version 2;
Part 1: Protocol specification" Part 1: Protocol specification"
[12] 3G TS 25.410 V3.1.0 (2000-01) Technical Specification - 3rd [12] 3G TS 25.410 V3.1.0 (2000-01) Technical Specification - 3rd
Generation partnership Project; Technical Specification Group Generation partnership Project; Technical Specification Group
Radio Access Network; UTRAN Iu Interface: General Aspects and Radio Access Network; UTRAN Iu Interface: General Aspects and
Principles (3G TS 25.410 Version 3.1.0 Release 1999) Principles (3G TS 25.410 Version 3.1.0 Release 1999)
[13] RFC 2719, "Stream Control Transport Protocol", R. Stewart et al, [13] RFC 2960, "Stream Control Transport Protocol", R. Stewart et al,
October 2000. October 2000.
[14] ITU-T Recommendations Q.701-Q.705, 'Signalling System No. 7 (SS7) [14] ITU-T Recommendations Q.701-Q.705, 'Signalling System No. 7 (SS7)
- Message Transfer Part (MTP)' - Message Transfer Part (MTP)'
[15] ANSI T1.111 'Signaling System Number 7 - Message Transfer Part' [15] ANSI T1.111 'Signaling System Number 7 - Message Transfer Part'
[16] ETSI ETS 300 008-1, "Integrated Services Digital Network (ISDN); [16] ETSI ETS 300 008-1, "Integrated Services Digital Network (ISDN);
Signalling System No.7; Message Transfer Part (MTP) to support Signalling System No.7; Message Transfer Part (MTP) to support
international interconnection; Part 1: Protocol specification" international interconnection; Part 1: Protocol specification"
[17] ITU-T Recommendation Q.2140 'B-ISDN ATM Adaptation Layer - Service [17] ITU-T Recommendation Q.2140 'B-ISDN ATM Adaptation Layer - Service
Specific Coordination Function for signalling at the Network Node Specific Coordination Function for signalling at the Network Node
Interface (SSCF at NNI) Interface (SSCF at NNI)
[18] ITU-T Recommendation Q.2110 'B-ISDN ATM Adaptation Layer - Service [18] ITU-T Recommendation Q.2110 'B-ISDN ATM Adaptation Layer - Service
Specific Connection Oriented Protocol (SSCOP) Specific Connection Oriented Protocol (SSCOP)
[19] MTP2-User Adaptation Layer <draft-ietf-sigtran-m2ua-01.txt>, Nov. [19] MTP2-User Adaptation Layer <draft-ietf-sigtran-m2ua-05.txt>, Nov.
1999, Work in Progress 2000, Work in Progress
[20] ITU-T Recommendation Q.2210 'B-ISDN MTP' [20] ITU-T Recommendation Q.2210 'B-ISDN MTP'
[21] RFC 2196, "Site Security Handbook", B. Fraser Ed., September 1997 [21] RFC 2196, "Site Security Handbook", B. Fraser Ed., September 1997
[22] RFC 2401, "Security Architecture for the Internet Protocol", S. [22] RFC 2401, "Security Architecture for the Internet Protocol", S.
Kent, R. Atkinson, November 1998. Kent, R. Atkinson, November 1998.
10.0 Author's Addresses 10.0 Author's Addresses
skipping to change at page 79, line 19 skipping to change at page 95, line 24
3685 Richmond Rd, 3685 Richmond Rd,
Nepean, Ontario, Canada K2H 5B7 Nepean, Ontario, Canada K2H 5B7
gregside@nortelnetworks.com gregside@nortelnetworks.com
Guy Mousseau Guy Mousseau
Nortel Networks Nortel Networks
3685 Richmond Rd 3685 Richmond Rd
Nepean, Ontario, Canada K2H 5B7 Nepean, Ontario, Canada K2H 5B7
Lyndon Ong Lyndon Ong
Nortel Networks Point Reyes Networks
4401 Great America Pkwy 1991 Concourse Dr.
Santa Clara, CA, USA 95054 San Jose, CA, USA 95131
long@nortelnetworks.com long@pointreyesnet.com
Ian Rytina Ian Rytina
Ericsson Australia Ericsson Australia
37/360 Elizabeth Street 37/360 Elizabeth Street
Melbourne, Victoria 3000, Australia Melbourne, Victoria 3000, Australia
ian.rytina@ericsson.com ian.rytina@ericsson.com
Hanns Juergen Schwarzbauer Hanns Juergen Schwarzbauer
SIEMENS AG SIEMENS AG
Hofmannstr. 51 Hofmannstr. 51
skipping to change at page 80, line 11 skipping to change at page 96, line 18
445 South Street 445 South Street
Morristown, NJ, USA 07960 Morristown, NJ, USA 07960
Email: kalla@research.telcordia.com Email: kalla@research.telcordia.com
Normand Glaude Normand Glaude
Performance Technologies Performance Technologies
150 Metcalf Sreet, Suite 1300 150 Metcalf Sreet, Suite 1300
Ottawa, Ontario, Canada K2P 1P1 Ottawa, Ontario, Canada K2P 1P1
EMail: nglaude@microlegend.com EMail: nglaude@microlegend.com
This draft expires May 2000. This draft expires August 2001.
 End of changes. 

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