draft-ietf-ccamp-pc-and-sc-reqs-02.txt   draft-ietf-ccamp-pc-and-sc-reqs-03.txt 
Network work group Diego Caviglia Network work group Diego Caviglia
Internet Draft Dino Bramanti Internet Draft Dino Bramanti
Ericsson Ericsson
Dan Li Dan Li
Huawei Huawei
Dave McDysan Dave McDysan
Verizon Verizon
Intended Status: Informational Intended Status: Informational
Expires: August, 18 2008 February 18, 2008 Expires: November, 19 2008 May 19, 2008
Requirements for the Conversion Between Permanent Connections and Requirements for the Conversion Between Permanent Connections and
Switched Connections in a Generalized Multiprotocol Label Switching Switched Connections in a Generalized Multiprotocol Label Switching
(GMPLS) Network (GMPLS) Network
draft-ietf-ccamp-pc-and-sc-reqs-02.txt draft-ietf-ccamp-pc-and-sc-reqs-03.txt
Status of this Memo Status of this Memo
By submitting this Internet-Draft, each author represents that By submitting this Internet-Draft, each author represents that
any applicable patent or other IPR claims of which he or she is any applicable patent or other IPR claims of which he or she is
aware have been or will be disclosed, and any of which he or she aware have been or will be disclosed, and any of which he or she
becomes aware will be disclosed, in accordance with Section 6 of becomes aware will be disclosed, in accordance with Section 6 of
BCP 79. BCP 79.
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
skipping to change at page 1, line 43 skipping to change at page 1, line 43
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
The list of current Internet-Drafts can be accessed at The list of current Internet-Drafts can be accessed at
http://www.ietf.org/ietf/1id-abstracts.txt http://www.ietf.org/ietf/1id-abstracts.txt
The list of Internet-Draft Shadow Directories can be accessed at The list of Internet-Draft Shadow Directories can be accessed at
http://www.ietf.org/shadow.html http://www.ietf.org/shadow.html
This Internet-Draft will expire on August 18, 2008. This Internet-Draft will expire on November 19, 2008.
Abstract Abstract
From a Carrier perspective, the possibility of turning a Permanent From a Carrier perspective, the possibility of turning a Permanent
Connection (PC) into a Soft Permanent Connection (SPC) and vice Connection (PC) into a Soft Permanent Connection (SPC) and vice
versa, without actually affecting Data Plane traffic being carried versa, without actually affecting Data Plane traffic being carried
over it, is a valuable option. In other terms, such operation can over it, is a valuable option. In other terms, such operation can
be seen as a way of transferring the ownership and control of an be seen as a way of transferring the ownership and control of an
existing and in-use Data Plane connection between the Management existing and in-use Data Plane connection between the Management
Plane and the Control Plane, leaving its Data Plane state untouched. Plane and the Control Plane, leaving its Data Plane state untouched.
skipping to change at page 3, line 8 skipping to change at page 3, line 8
9.1. Normative References....................................9 9.1. Normative References....................................9
9.2. Informative References..................................9 9.2. Informative References..................................9
10. Acknowledgments.............................................9 10. Acknowledgments.............................................9
11. Authors' Addresses.........................................10 11. Authors' Addresses.........................................10
12. Full Copyright Statement...................................11 12. Full Copyright Statement...................................11
13. Intellectual Property Statement............................11 13. Intellectual Property Statement............................11
1. Introduction 1. Introduction
In a typical, traditional transport network scenario, Data Plane In a typical, traditional transport network scenario, Data Plane
connections between two endpoints are controlled by means of a connections between two end-points are controlled by means of a
Network Management System (NMS) operating within the Management Plane Network Management System (NMS) operating within the Management Plane
(MP). The NMS/MP is the owner of such transport connections, being (MP). The NMS/MP is the owner of such transport connections, being
responsible of their setup, teardown, and maintenance. Provisioned responsible of their setup, teardown, and maintenance. Provisioned
connections of this kind, initiated and managed by the Management connections of this kind, initiated and managed by the Management
Plane, are known as Permanent Connections (PCs) [G.8081]. Plane, are known as Permanent Connections (PCs) [G.8081].
When the setup, teardown, and maintenance of connections are achieved When the setup, teardown, and maintenance of connections are achieved
by means of a signaling protocol owned by the Control Plane such by means of a signaling protocol owned by the Control Plane such
connections are known as Switched Connections (SCs) [G.8081]. connections are known as Switched Connections (SCs) [G.8081].
In many deployments a hybrid connection type will be used. A Soft In many deployments a hybrid connection type will be used. A Soft
Permanent Connection (SPC) is a combination of a permanent connection Permanent Connection (SPC) is a combination of a permanent connection
segment at the source user-to-network side, a permanent connection segment at the source user-to-network side, a permanent connection
segment at the destination user-to-network side, and a switched segment at the destination user-to-network side, and a switched
connection segment within the core network. The permanent parts of connection segment within the core network. The permanent parts of
the SPC are owned by the Management Plane, and the switched parts are the SPC are owned by the Management Plane, and the switched parts are
owned by the Control Plane [G.8081]. owned by the Control Plane [G.8081].
At least some control plane initiated aspects of a connection must be At least some aspects of a control plane initiated connection must be
capable of being queried by the management plane. These aspects capable of being queried by the Management Plane. These aspects
should be independent of how the connection was established. should be independent of how the connection was established.
2. Motivation 2. Motivation
The main motivation for this work is the LSP conversion from The main motivation for this work is the LSP conversion from
Management Plane PC to Control Plane SC. The objective is to be able Management Plane PC to Control Plane SC. The objective is to be able
to introduce a control plane into an existing network without to introduce a control plane into an existing network without
disrupting user traffic. An example of this is an operator disrupting user traffic. An example of this is an operator
establishing PCs before the SC technology is mature, or SC establishing PCs before the SC technology is mature, or before SC
interoperation is achieved between multiple implementations. interoperation is achieved between multiple implementations.
Conversion from the Management Plane to Control Plane is proposed as Conversion from the Management Plane to Control Plane is stated as
a mandatory requirement while the conversion from the Control Plane a mandatory requirement while the conversion from the Control Plane
to Management is seen as a nice to have, or desirable, feature. The to Management is a desirable feature, or desirable, feature. The
requirement for LSP conversion from Control Plane to Management Plane requirement for LSP conversion from Control Plane to Management Plane
should be scoped as a back-out procedure. is scoped as a back-out procedure.
A significant benefit of GMPLS in networks is discovering and A significant benefit of GMPLS in networks is discovering and
validating the current state of the network. For example, an operator validating the current state of the network. For example, an operator
could invoke an SC, determine that the automatically discovered path could invoke an SC, determine that the automatically discovered path
is good and then "pin" a connection to this specific path using the is good and then "pin" a connection to this specific path using the
SC to PC conversion procedures. This is attractive to network SC to PC conversion procedures. This is attractive to network
operators who prefer the static nature of the path for a PC as operators who prefer the static nature of the path for a PC as
compared with the potentially dynamic path of an SC. compared with the potentially dynamic path of an SC.
3. Label Switched Path Terminology 3. Label Switched Path Terminology
A Label Switched Path (LSP) has different semantics depending on the A Label Switched Path (LSP) has different semantics depending on the
plane in which it the term is used. plane in which it the term is used.
In the Data Plane, an LSP indicates the Data Plane forwarding path. In the Data Plane, an LSP indicates the Data Plane forwarding path.
It defines the forwarding or switching operations at each network It defines the forwarding or switching operations at each network
entity. It is the sequence of data plane resources (links, labels, entity. It is the sequence of Data Plane resources (links, labels,
cross-connects) that achieves end-to-end data transport. cross-connects) that achieves end-to-end data transport.
In the Management Plane, an LSP is the management state information In the Management Plane, an LSP is the management state information
(such as the connection attributes and path information) associated (such as the connection attributes and path information) associated
with and necessary for the creation and maintenance of a Data Plane with and necessary for the creation and maintenance of a Data Plane
connection. connection.
In the Control Plane, an LSP is the control plane state information In the Control Plane, an LSP is the Control Plane state information
(such as Path and Resv state) associated with and necessary for the (such as RSVP-TE [RFC3473] Path and Resv state) associated with and necessary for the
creation and maintenance of a Data Plane connection. creation and maintenance of a Data Plane connection.
A Permanent Connection has an LSP presence in the Data Plane and the A Permanent Connection has an LSP presence in the Data Plane and the
Management Plane. A Switched Connection has an LSP presence in the Management Plane. A Switched Connection has an LSP presence in the
Data Plane and the Control Plane. An SPC has LSP presence in the Data Data Plane and the Control Plane. An SPC has LSP presence in the Data
Plane for its entire length, but has Management Plane presence for Plane for its entire length, but has Management Plane presence for
part of its length and Control Plane presence for part of its length. part of its length and Control Plane presence for part of its length.
In this document, when we talk about the LSP conversion between In this document, when we talk about the LSP conversion between
Management Plane and Control Plane, we mainly focus on the conversion Management Plane and Control Plane, we mainly focus on the conversion
of Control Plane state information and Management Plane state of Control Plane state information and Management Plane state
information. information.
4. LSP within GMPLS Control Plane 4. LSP within GMPLS Control Plane
Generalized Multiprotocol Label Switching (GMPLS) [RFC 3471], [RFC Generalized Multiprotocol Label Switching (GMPLS) [RFC3471], [RFC3473] [RFC3945]
3473] defines a powerful Control Plane architecture for transport defines a powerful Control Plane architecture for transport
networks. This includes both routing and signaling protocols for the networks. This includes both routing and signaling protocols for the
creation and maintenance of Label Switched Paths (LSPs) in networks creation and maintenance of Label Switched Paths (LSPs) in networks
whose Data Plane is based on different technologies such as TDM whose Data Plane is based on different technologies such as TDM
(SDH/SONET G.709 at ODUk level) transport and WDM (G.709 OCh level). (SDH/SONET G.709 at ODUk level) transport and WDM (G.709 OCh level).
4.1. Resource Ownership 4.1. Resource Ownership
A resource used by an LSP is said to be 'owned' by the plane that was A resource used by an LSP is said to be 'owned' by the plane that was
used to set up the LSP through that part of the network. Thus, all used to set up the LSP through that part of the network. Thus, all
the resources used by a Permanent Connection are owned by the the resources used by a Permanent Connection are owned by the
Management Plane, and all the resources used by a Switched Connection Management Plane, and all the resources used by a Switched Connection
are owned by the Control Plane. The resources used by an SPC are are owned by the Control Plane. The resources used by an SPC are
divided between the Management Plane (for the resources used by the divided between the Management Plane (for the resources used by the
permanent connection segments at the edge of the network) and the permanent connection segments at the edge of the network) and the
Control Plane (for the resources used by the switched segment in the Control Plane (for the resources used by the switched segment in the
middle of the network). Note that the management plane assigns middle of the network).
resources to the control plane.
The division of resources available for ownership by the Management The division of resources available for ownership by the Management
and Control Planes is an architectural issue. A carrier may decide to and Control Planes is an architectural issue. A carrier may decide to
pre-partition the resources at a network entity so that LSPs under pre-partition the resources at a network entity so that LSPs under
Management Plane control use one set of resources and LSPs under Management Plane control use one set of resources and LSPs under
Control Plane control use another set of resources. Other carriers Control Plane control use another set of resources. Other carriers
may choose to make this distinction resource-by-resource as LSPs are may choose to make this distinction resource-by-resource as LSPs are
established. established.
It should be noted, however, that even when a resource is owned by It should be noted, however, that even when a resource is owned by
skipping to change at page 6, line 26 skipping to change at page 6, line 26
to be completed for all hops. If conversion cannot be done for all to be completed for all hops. If conversion cannot be done for all
hops, then the conversion must be done for no hops and the state of hops, then the conversion must be done for no hops and the state of
the hop level information restored to that before the conversion was the hop level information restored to that before the conversion was
attempted, and an error condition reported to the management system. attempted, and an error condition reported to the management system.
In either case of conversion, the Management Plane shall initiate the In either case of conversion, the Management Plane shall initiate the
change. When converting from a PC to an SC, the management system change. When converting from a PC to an SC, the management system
must somehow indicate to each hop that a control protocol is now to must somehow indicate to each hop that a control protocol is now to
be used, and then configure the data needed by control protocol at be used, and then configure the data needed by control protocol at
the connection endpoints. When converting from an SC to a PC, the the connection endpoints. When converting from an SC to a PC, the
management plane must change the owner of each hop. Somehow, then the Management Plane must change the owner of each hop. Somehow, then the
instance in the control plane must be removed without affecting the instance in the Control Plane must be removed without affecting the
data plane. This may best be done via a make before break operation. Data Plane.
The case where the CP and/or MP fail at one or more nodes during the The case where the CP and/or MP fail at one or more nodes during the
conversion procedure must be handled in the solution. If the network conversion procedure must be handled in the solution. If the network
is viewed as the database of record (including data, control and is viewed as the database of record (including data, control and
management plane elements), then a solution that has procedures Management Plane elements), then a solution that has procedures
similar to those of a two-phase database commit process may be needed similar to those of a two-phase database commit process may be needed
to ensure integrity and support the need to revert to the state prior to ensure integrity and support the need to revert to the state prior
to the conversion attempt if there is a CP and/or MP failure during to the conversion attempt if there is a CP and/or MP failure during
the attempted conversion. the attempted conversion.
5. Typical Use Cases 5. Typical Use Cases
5.1. PC to SC/SPC Conversion 5.1. PC to SC/SPC Conversion
A typical scenario where a PC to SC (or SPC) procedure can be a A typical scenario where a PC to SC (or SPC) procedure can be a
useful option is at the initial stage of Control Plane deployment in useful option is at the initial stage of Control Plane deployment in
an existing network. In such a case all the network connections, an existing network. In such a case all the network connections,
possibly carrying traffic, are already set up as PCs and are owned by possibly carrying traffic, are already set up as PCs and are owned by
the Management Plane. the Management Plane.
Next step in such conversion process presents a similar scenario The next step in this conversion process presents a similar scenario
where the network is partially controlled by the Management Plane and where the network is partially controlled by the Management Plane and
partially controlled by the Control Plane (PCs and SCs/SPCs coexist). partially controlled by the Control Plane (PCs and SCs/SPCs coexist).
In this case a network upgrade by a Control Plane coverage extension In this case an upgrade of the Control Plane functionalities, such as
may be required. new signaling extensions, may be required.
In both cases the point is that a connection, set up and owned by In both cases the point is that a connection, set up and owned by
the Management Plane, may need to be transferred to Control Plane the Management Plane, may need to be transferred to Control Plane
control. If a connection is carrying traffic, its transfer has to be control. If a connection is carrying traffic, its transfer has to be
done without any disruption to the Data Plane traffic. done without any disruption to the Data Plane traffic.
5.2. SC to PC Conversion 5.2. SC to PC Conversion
The main reason making a SC to PC conversion interesting is to give The main reason making a SC to PC conversion interesting is to give
an operator the chance of undoing somehow the action represented by an operator the chance of undoing somehow the action represented by
skipping to change at page 7, line 32 skipping to change at page 7, line 32
Again it is worth stressing the requirement that such 'SPC to PC' Again it is worth stressing the requirement that such 'SPC to PC'
conversion is achieved without any effect on the associated Data conversion is achieved without any effect on the associated Data
Plane state so that the connection continues to be operational and to Plane state so that the connection continues to be operational and to
carry traffic during the transition. carry traffic during the transition.
6. Requirements 6. Requirements
This section sets out the basic requirements for procedures and This section sets out the basic requirements for procedures and
processes that are used to perform the functions this document is processes that are used to perform the functions this document is
about. about. Notation form [RFC2119] is used to clarify the level of each
requirement.
6.1. Data Plane LSP Consistency 6.1. Data Plane LSP Consistency
The Data Plane LSP, staying in place throughout the whole transfer The Data Plane LSP, staying in place throughout the whole transfer
process, MUST follow the same path through the network and MUST use process, MUST follow the same path through the network and MUST use
the same network resources. the same network resources.
6.2. No Disruption of User Traffic 6.2. No Disruption of User Traffic
The transfer process MUST NOT cause any disruption of user traffic The transfer process MUST NOT cause any disruption of user traffic
flowing over the LSP whose control is being transferred or any other flowing over the LSP whose control is being transferred or any other
LSP in the network. LSP in the network.
SC to PC conversion and vice-versa shall occur without generating SC to PC conversion and vice-versa SHALL occur without generating
management plane alarms toward the end users at neither the UNI Management Plane alarms toward the end users at neither the UNI
endpoints nor the NMS. endpoints nor the NMS.
6.3. Transfer from Management Plane to Control Plane 6.3. Transfer from Management Plane to Control Plane
It MUST be possible to transfer the ownership of an LSP from the It MUST be possible to transfer the ownership of an LSP from the
Management Plane to the Control Plane Management Plane to the Control Plane
6.4. Transfer from Control Plane to Management Plane 6.4. Transfer from Control Plane to Management Plane
It SHOULD be possible to transfer the ownership of an LSP from the It SHOULD be possible to transfer the ownership of an LSP from the
Control Plane to the Management Plane. Control Plane to the Management Plane.
6.5. Synchronization of state among nodes during conversion 6.5. Synchronization of State Among Nodes During Conversion
It MUST be assured that the state of the LSP is synchronized among It MUST be assured that the state of the LSP is synchronized among
all nodes traversed by it before proceeding to the conversion. all nodes traversed by it before the conversion in considered complete.
6.6. Support of Soft Permanent Connections 6.6. Support of Soft Permanent Connections
It MUST be possible to segment an LSP such that it is converted to or It MUST be possible to segment an LSP such that it is converted to or
from an SPC. from an SPC.
6.7. Failure of Transfer 6.7. Failure of Transfer
It MUST be possible for a transfer from one plane to the other to It MUST be possible for a transfer from one plane to the other to
fail in a non-destructive way leaving the ownership unchanged and fail in a non-destructive way leaving the ownership unchanged and
skipping to change at page 9, line 7 skipping to change at page 9, line 7
Allowing control of an LSP to be taken away from a plane introduces Allowing control of an LSP to be taken away from a plane introduces
another way in which services may be disrupted by malicious another way in which services may be disrupted by malicious
intervention. intervention.
It is expected that any solution to the requirements in this document It is expected that any solution to the requirements in this document
will utilize the security mechanisms inherent in the Management Plane will utilize the security mechanisms inherent in the Management Plane
and Control Plane protocols, and no new security mechanisms are and Control Plane protocols, and no new security mechanisms are
needed if these tools are correctly used. needed if these tools are correctly used.
If SNMP MIBs are used for configuration, then the management plane If SNMP MIBs are used for configuration, then the Management Plane
should support at least authentication for PC<>SC configuration should support at least authentication for PC<>SC configuration
changes as specified in [RFC 3414]. changes as specified in [RFC 3414].
Note also that implementations may enable policy components to help Note also that implementations may enable policy components to help
determine whether individual LSPs may be transferred between planes. determine whether individual LSPs may be transferred between planes.
8. IANA Considerations 8. IANA Considerations
This requirement document makes no requests for IANA action. This requirement document makes no requests for IANA action.
skipping to change at page 9, line 39 skipping to change at page 9, line 39
9.2. Informative References 9.2. Informative References
[RFC 3471] L. Berger (Ed.) "Generalized Multi-Protocol Label [RFC 3471] L. Berger (Ed.) "Generalized Multi-Protocol Label
Switching (GMPLS) Signaling Functional Description", RFC Switching (GMPLS) Signaling Functional Description", RFC
3471, January 2003 3471, January 2003
[RFC 3473] L. Berger (Ed.) "Generalized Multi-Protocol Label [RFC 3473] L. Berger (Ed.) "Generalized Multi-Protocol Label
Switching (GMPLS) Signaling Resource ReserVation Switching (GMPLS) Signaling Resource ReserVation
Protocol-Traffic Engineering (RSVP-TE) Extensions", RFC Protocol-Traffic Engineering (RSVP-TE) Extensions", RFC
3473, January 2003 3473, January 2003
[RFC3945] E. Mannie (Ed.) "Generalized Multi-Protocol Label
Switching (GMPLS) Architecture", RFC 3945, October 2004
10. Acknowledgments 10. Acknowledgments
We whish to thank the following people (listed randomly) Adrian We whish to thank the following people (listed randomly) Adrian
Farrel for his editorial assistance to prepare this draft for Farrel for his editorial assistance to prepare this draft for
publication, Dean Cheng and Julien Meuric, Dimitri Papadimitriou, publication, Dean Cheng and Julien Meuric, Dimitri Papadimitriou,
Deborah Brungard, Igor Bryskin, Lou Berger, Don Fedyk, John Drake and Deborah Brungard, Igor Bryskin, Lou Berger, Don Fedyk, John Drake and
Vijay Pandian for their suggestions and comments on the CCAMP list. Vijay Pandian for their suggestions and comments on the CCAMP list.
11. Authors' Addresses 11. Authors' Addresses
 End of changes. 23 change blocks. 
30 lines changed or deleted 32 lines changed or added

This html diff was produced by rfcdiff 1.34. The latest version is available from http://tools.ietf.org/tools/rfcdiff/