draft-ietf-gsmp-applicability-00.txt   draft-ietf-gsmp-applicability-01.txt 
INTERNET DRAFT Avri Doria, Nokia INTERNET DRAFT Avri Doria
GSMP Working Group Kenneth Sundell, Nortel Networks GSMP Working Group Kenneth Sundell
Standards Track 10 March, 2000 Informational Track Nortel Networks
July 2000
General Switch Management Protocol Applicability General Switch Management Protocol Applicability
<draft-ietf-gsmp-applicability-00.txt> <draft-ietf-gsmp-applicability-01.txt>
This document is an Internet-Draft and is in full conformance with This document is an Internet-Draft and is in full conformance with
all provisions of Section 10 of RFC2026. all provisions of Section 10 of RFC2026.
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups. Note that Task Force (IETF), its areas, and its working groups. Note that
other groups may also distribute working documents as Internet- other groups may also distribute working documents as Internet-
Drafts. Drafts.
Internet-Drafts are draft documents valid for a maximum of six Internet-Drafts are draft documents valid for a maximum of six
skipping to change at page 2, line 9 skipping to change at page 2, line 9
Abstract Abstract
This memo provides an overview of the GSMP protocol and includes This memo provides an overview of the GSMP protocol and includes
information relating to its deployment in a MPLS environment. information relating to its deployment in a MPLS environment.
1. Overview 1. Overview
The General Switch Management Protocol (GSMP) has been available The General Switch Management Protocol (GSMP) has been available
to the IETF community for several years now as informational to the IETF community for several years now as informational
RFC's. Both V1.1 released in March 1996 as RFC1987 [2], and V2.0 RFC's. Both GSMPv1.1 released in March 1996 as RFC1987 [2], and
released in August 1998 as RFC2297 [3] are available. V1.1 has GSMPv2.0 released in August 1998 as RFC2297 [3] are available.
been implemented by several vendors. Several vendors have implemented GSMPv1.1.
In V1.1 and V2 GSMP was intended only for use with ATM switches. In V1.1 and V2 GSMP was intended only for use with ATM switches.
During the course of the last year, the GSMP working group has During the course of the last year, the GSMP working group has
decided to expand the purview of GSMP to the point where it can be decided to expand the purview of GSMP to the point where it can be
used to control a number of different kinds of switch and can thus used to control a number of different kinds of switch and can thus
live up to what its name indicates; a general switch management live up to what its name indicates; a general switch management
protocol. To do this, commands and arguments needed to be protocol. To do this, commands and arguments needed to be
generalised, with sections added discussing the manner in which generalised, with sections added discussing the manner in which
the generalised protocol could be applied to specific kinds of the generalised protocol could be applied to specific kinds of
switches and port types. In short the protocol has gone through switches and port types. In short the protocol has gone through
major changes in the last 18 months. major changes in the last 24 months.
GSMP provides an interface which can be used to separate the data GSMP provides an interface that can be used to separate the data
forwarder from the routing and other control plane protocols such forwarder from the routing and other control plane protocols such
as LDP. As such it allows service providers to move away from as LDP. As such it allows service providers to move away from
monolithic systems which bundle control plane and data plane into monolithic systems that bundle control plane and data plane into a
a single tightly coupled system - usually in a single chassis. single tightly coupled system - usually in a single chassis.
Separating the control components from the forwarding components Separating the control components from the forwarding components
and using GSMP for switch management, enables service providers to and using GSMP for switch management, enables service providers to
create multi-service systems composed of various vendors create multi-service systems composed of various vendors
equipment. equipment. It also allows for a more dynamic means of adding
services to their networks.
The IETF GSMP working group was established in the routing area The IETF GSMP working group was established in the routing area
because GSMP was being seen as an optional part of the MPLS because GSMP was being seen as an optional part of the MPLS
solution. In a MPLS system, it is possible to run the routing solution. In a MPLS system, it is possible to run the routing
protocols and label distribution protocols on one system while protocols and label distribution protocols on one system while
passing data across a generic switch, e.g. an ATM switch. GSMP passing data across a generic switch, e.g. an ATM switch. GSMP
provides the management mechanism needed in such a scenario. provides the switch resource management mechanism needed in such a
scenario.
GSMP has also been selected by the Multiservice Switching GSMP has also been selected by the Multiservice Switching
Forum(MSF) as its protocol of choice for the Switch Control Forum(MSF) as its protocol of choice for the Switch Control
Interface identified in their architecture. The MSF is an Interface identified in their architecture. The MSF is an
industry forum which establishes their member's requirements and industry forum, which among its activities establishes their
then works with the appropriate standards bodies to foster their member's requirements and then works with the appropriate
goals. In the case of GSMP, the MSF presented the IETF GSMP standards bodies to foster their goals. In the case of GSMP, the
Working Group with a set of requirements for GSMP. The working MSF presented the IETF GSMP Working Group with a set of
group has made a determined effort to comply with those requirements for GSMP. The working group has made a determined
requirements. effort to comply with those requirements in its specifications.
2. GSMP V3 Document Set 2. GSMP V3 Document Set
The current version of GSMP is documented in 3 documents: The current version of GSMP is documented in 3 documents:
- General Switch Management protocol V3 [5] - GSMP: General Switch Management protocol V3 [5]
- GSMP Packet Encapsulations for ATM, Ethernet and TCP - GSMP-ENCAPS: GSMP Packet Encapsulations for ATM, Ethernet
and TCP[4]
- Definitions of Managed Objects for the General Switch - GSMP-MIB: Definitions of Managed Objects for the General
Management Protocol [1] Switch Management Protocol [1]
3. Description of protocol 3. General Description
The General Switch Management Protocol V3 (GSMPv3) [5], is a The General Switch Management Protocol V3 (GSMPv3) [5], is a
general purpose protocol to control a label switch. GSMP allows general purpose protocol to control a label switch. GSMP allows
a controller to establish and release connections across the a controller to establish and release connections across the
switch; add and delete leaves on a multicast connection; switch; add and delete leaves on a multicast connection;
reserve resources; manage switch ports; request configuration reserve resources; manage switch ports; request configuration
information; and request statistics. It also allows the switch information; and request statistics. It also allows the switch
to inform the controller of asynchronous events such as a link to inform the controller of asynchronous events such as a link
going down. The GSMP protocol is asymmetric, the controller going down. The GSMP protocol is asymmetric, the controller
being the master and the switch being the slave. being the master and the switch being the slave.
A physical switch can be partitioned in many virtual switches. A physical switch can be partitioned in many virtual switches.
GSMP does not provide support for defining switch partitions. GSMP does not provide support for defining switch partitions.
GSMP treats a virtual switch as if it were a physical switch. GSMP treats a virtual switch as if it were a physical switch.
GSMP may be transported in three ways: GSMP may be transported in three ways:
- GSMP may run across an ATM link connecting the controller - GSMP operation across an IP network is specified.
to the switch, on a control connection (virtual channel)
established at initialisation.
- GSMP operation across an Ethernet link is specified. - GSMP operation across an ATM virtual channel is specified.
- GSMP operation across an IP network is specified. - GSMP operation across an Ethernet link is specified.
Other encapsulation are possible, but have not been defined. Other encapsulations are possible, but have not been defined.
Encapsulation are defined in a separate standards track document. Encapsulations are defined in [4].
A label switch is a frame or cell switch that supports connection A label switch is a frame or cell switch that supports connection
oriented switching using the exact match forwarding algorithm oriented switching using the exact match forwarding algorithm
based on labels attached to incoming cells or frames. based on labels attached to incoming cells or frames.
A label switch may support multiple label types, however, each A label switch may support multiple label types, however, each
switch port can support only one label type. The label type switch port can support only one label type. The label type
supported by a given port is indicated by the switch to the supported by a given port is indicated in a port configuration
controller in a port configuration message. Connections may be message. Connections may be established between ports
established between ports supporting different label types. supporting different label types using the adaptation methods.
There are two forms of labels support; short 28 bit labels There are two forms of labels support; short 28 bit labels
which are sufficient for many purposes and TLV labels which are which are sufficient for many purposes and TLV labels which are
defined for labels that do not fit in 28 bits. Examples of the defined for labels that do not fit in 28 bits. Examples of the
label types which use the short form include ATM, Frame Relay, label types that can use the short form include ATM, Frame
and MPLS Generic Labels. Examples of labels which use the TLV Relay, and MPLS Generic Labels. Examples of labels which are
form include DS1, DS3, E1, E3 and MPLS FECs. defined to use the TLV form include DS1, DS3, E1, E3 and MPLS
FECs.
A connection across a switch is formed by connecting an incoming A connection across a switch is formed by connecting an incoming
labelled channel to one or more outgoing labelled channels. labelled channel to one or more outgoing labelled channels.
Connections are generally referenced by the input port on which Connections are generally referenced by the input port on which
they arrive and the Labels values of their incoming labelled they arrive and the label values of their incoming labelled
channel. In some messages connections are referenced by the channel. In some messages connections are referenced by the
output port. output port.
GSMP supports point-to-point and point-to-multipoint connections. GSMP supports point-to-point and point-to-multipoint connections.
A multipoint-to-point connection is specified by establishing A multipoint-to-point connection is specified by establishing
multiple point-to-point connections each of them specifying the multiple point-to-point connections each of which specifies the
same output branch. A multipoint-to-multipoint connection is same output label. A multipoint-to-multipoint connection is
specified by establishing multiple point-to-multipoint trees specified by establishing multiple point-to-multipoint
each of them specifying the same output branches. connections each of which specifies a different input label
with the same output labels.
In general a connection is established with a certain quality of In general a connection is established with a certain quality of
service (QoS). This version of GSMP includes a default QoS service (QoS). This version of GSMP includes a default QoS
Configuration and additionally allows the negotiation of Configuration and additionally allows the negotiation of
alternative, optional QoS configurations. The default QoS alternative, optional QoS configurations. The default QoS
Configuration includes three QoS Models: a default service Configuration includes three QoS Models: a default service
model, a simple priority model and a QoS profile model. model, a simple priority model and a QoS profile model. This
version of GSMP also supports the reservation of resources when
the labels are not yet known. This ability can be used in
support of MPLS.
GSMP contains an adjacency protocol. The adjacency protocol is GSMP contains an adjacency protocol. The adjacency protocol is
used to synchronise state across the link, to negotiate which used to synchronise state across the link, to negotiate which
version of the GSMP protocol to use, to discover the identity version of the GSMP protocol to use, to discover the identity
of the entity at the other end of a link, and to detect when it of the entity at the other end of a link, and to detect when it
changes. changes.
3.1 Switch Partitioning 3.1 Switch Partitioning
In this version of GSMP switch partitioning is static and occurs In this version of GSMP switch partitioning is static and occurs
prior to running GSMP. The partitions of a physical switch are prior to running GSMP. The partitions of a physical switch are
isolated from each other by the implementation and the controller isolated from each other by the implementation and the controller
assumes that the resources allocated to a partition are at all assumes that the resources allocated to a partition are at all
times available to that partition and only to that partition. A times available to that partition and only to that partition. A
partition appears to its controller as a physical label switch. partition appears to its controller as a physical label switch.
The resources allocated to a partition appear to the controller as The resources allocated to a partition appear to the controller as
if they were the actual physical resources of the partition. For if they were the actual physical resources of a physical switch.
example if the bandwidth of a port is divided among several For example if the bandwidth of a port is divided among several
partitions, each partition would appear to the controller to have partitions, each partition would appear to the controller to have
its own independent port. its own independent port with its fixed set or resources.
GSMP controls a partitioned switch through the use of a partition GSMP controls a partitioned switch through the use of a partition
identifier which is carried in every GSMP message. Each partition identifier that is carried in every GSMP message. Each partition
has a one-to-one control relationship with its own logical has a one-to-one control relationship with its own logical
controller entity (which in the remainder of the document is controller entity (which in the remainder of the document is
referred to simply as a controller) and GSMP independently referred to simply as a controller) and GSMP independently
maintains adjacency between each controller-partition pair. maintains adjacency between each controller-partition pair.
3.2 Switch and controller interactions 3.2 Switch and controller interactions
Multiple switches may be controlled by a single controller using Multiple switches may be controlled by a single controller using
multiple instantiations of the protocol over separate control multiple instantiations of the protocol over separate control
connections. connections.
Alternatively, multiple controllers can control a single switch. Alternatively, multiple controllers can control a single switch.
Each controller would establish a control connection to the switch Each controller would establish a control connection to the switch
using the adjacency protocol. The adjacency mechanism maintains a using the adjacency protocol. The adjacency mechanism maintains a
state table indicating which the control connections that are state table indicating the control connections that are being
being maintained to the same partition. The switch provides maintained by the same partition. The switch provides information
minimal information to the controller group about the number and to the controller group about the number and identity of the
identity of the attached controllers. It does nothing, however, attached controllers. It does nothing, however, to co-ordinate
to co-ordinate the activities of the controllers, and will execute the activities of the controllers, and will execute all commands
all commands as they are received. It is the controller group as they are received. It is the controller group responsibility
responsibility to co-ordinate its use of the switch. This to co-ordinate its use of the switch. This mechanism is most
mechanism is most commonly used for controller redundancy and load commonly used for controller redundancy and load sharing.
sharing. Definition of the mechanism controllers use to co- Definition of the mechanism by which controllers use to co-
ordinate their control is not within GSMP's scope. ordinate their control is not within GSMP's scope.
3.3 Service support 3.3 Service support
All GSMP switches must support the default QoS Configuration. A All GSMP switches must support the default QoS Configuration. A
GSMP switch may additionally support one or more alternative QoS GSMP switch may additionally support one or more alternative QoS
Configurations. GSMP includes a negotiation mechanism that allows Configurations. GSMP includes a negotiation mechanism that allows
a controller to select from the QoS configurations that a switch a controller to select from the QoS configurations that a switch
supports. supports.
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In the Simple Abstract Model a connection is assigned a In the Simple Abstract Model a connection is assigned a
priority when it is established. It may be assumed that for priority when it is established. It may be assumed that for
connections that share the same output port, an cell or connections that share the same output port, an cell or
frame on a connection with a higher priority is much more frame on a connection with a higher priority is much more
likely to exit the switch before a cell or frame on a likely to exit the switch before a cell or frame on a
connection with a lower priority if they are both in the connection with a lower priority if they are both in the
switch at the same time. switch at the same time.
The QoS Profile Model provides a simple mechanism that allows The QoS Profile Model provides a simple mechanism that allows
connection to be assigned QoS semantics defined external to QoS semantics defined externally to GSMP to be assigned to
GSMP. Each profile is an opaque indicator which has been connections. Each profile is an opaque indicator that has
predefined in the controller and in the switch. been predefined in the controller and in the switch.
4. Summary of Message Set 4. Summary of Message Set
The following table gives a summary of the messages defined in The following table gives a summary of the messages defined in
this version of the specification. It also makes a recommendation this version of the specification. It also makes a recommendation
of the minimal set of messages that should be supported in an MPLS of the minimal set of messages that should be supported in an MPLS
environment. These messages will be labelled as "Required", environment. These messages will be labelled as "Required",
though the service provided by the other messages are essential though the service provided by the other messages are essential
for the operation of carrier quality controller/ switch for the operation of carrier quality controller/ switch
operations. V1.1 or V2 commands which are no longer support are operations. GSMPv1.1 or GSMPv2 commands that are no longer
marked as "Obsolete" and should no longer be used. support are marked as "Obsolete" and should no longer be used.
4.1 Messages Table 4.1 Messages Table
Message Name Message Number Status Message Name Message Number Status
Connection Management Messages Connection Management Messages
Add Branch .......................16 Required Add Branch .......................16 Required
ATM Specific - VPC............26 ATM Specific - VPC............26
Delete Tree.......................18 Delete Tree.......................18
Verify Tree.......................19 Obsoleted Verify Tree.......................19 Obsoleted
Delete All Input..................20 Delete All Input..................20
Delete All Output.................21 Delete All Output.................21
Delete Branches...................17 Required Delete Branches...................17 Required
Move Output Branch............... 22 Move Output Branch............... 22
ATM Specific - VPC............27 ATM Specific - VPC............27
Move Input Branch.................23 Move Input Branch.................23
ATM Specifc - VPC............28 ATM Specific - VPC............28
Port Management Messages Port Management Messages
Port Management...................32 Required Port Management...................32 Required
Label Range.......................33 Label Range.......................33
State and Statistics Messages State and Statistics Messages
Connection Activity...............48 Connection Activity...............48
Port Statistics...................49 Required Port Statistics...................49 Required
Connection Statistics.............50 Connection Statistics.............50
QoS Class Statistics..............51 Reserved QoS Class Statistics..............51 Reserved
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Adjacency Protocol....................10 Required Adjacency Protocol....................10 Required
5. Security Considerations 5. Security Considerations
The security of GSMP's TCP/IP control channel has been addressed The security of GSMP's TCP/IP control channel has been addressed
in [4]. Any potential remaining security considerations are not in [4]. Any potential remaining security considerations are not
addressed in the current revision of this draft. addressed in the current revision of this draft.
References References
[1] Sjostrand, H., "Definitions of Managed Objects for the [1] [GSMP-MIB] Sjostrand, H., "Definitions of Managed Objects
General Switch Management Protocol (GSMP)," Internet-Draft for the General Switch Management Protocol
draft-ietf-gsmp-mib-01, March 2000. (GSMP),"Internet-Draft draft-ietf-gsmp-mib-
02", July 2000. work in progress
[2] Newman, P, Edwards, W., Hinden, R., Hoffman, E. Ching
Liaw, F., Lyon, T. and Minshall, G., "Ipsilon's General
Switch Management Protocol Specification," Version 1.1,
RFC 1987, August 1996.
[3] Newman, P, Edwards, W., Hinden, R., Hoffman, E., Ching [2] [GSMPv1.1] Newman, P, Edwards, W., Hinden, R., Hoffman, E.
Liaw, F., Lyon, T. and Minshall, G., "Ipsilon's General Ching Liaw, F., Lyon, T. and Minshall, G.,
Switch Management Protocol Specification," Version 2.0, "Ipsilon's General Switch Management Protocol
RFC 2397, March 1998. Specification," Version 1.1, RFC 1987, August
1996.
[4] T. Worster, "GSMP Packet Encapsulations for ATM, Ethernet [3] [GSMPv2] Newman, P, Edwards, W., Hinden, R., Hoffman,
and TCP," Internet-Draft draft-ietf-gsmp-encaps-00, Jan E., Ching Liaw, F., Lyon, T. and Minshall, G.,
2000. "Ipsilon's General Switch Management Protocol
Specification," Version 2.0, RFC 2397, March
1998.
[5] Doria, A, Sundell, K, Hellstrand, F, Worster, T, "General [4] [GSMP-ENCAPS] T. Worster, "GSMP Packet Encapsulations for
switch Management Protocol V3," Internet Draft draft-ietf- ATM, Ethernet and TCP," Internet-Draft draft-
gsmp-04.txt, March 2000 ietf-gsmp-encaps-02, July 2000. work in
progress
[6] Worster, T,. " GSMP Packet Encapsulations for ATM, [5] [GSMP] Doria, A, Sundell, K, Hellstrand, F, Worster,
Ethernet and TCP," Internet Draft draft-ietf-gsmp-encaps- T, "General switch Management Protocol V3,"
00.txt, October 1999 Internet Draft draft-ietf-gsmp-06.txt, July
2000. work in progress
Authors' Addresses Authors' Addresses
Avri Doria Avri Doria
Nokia Nortel Networks
5 Wayside Road 600 Technology Park Drive
Burlington MA 01803 Billerica, MA
Phone: +1 781 993 4656 Phone: +1 401 663 5024
avri.doria@nokia.com avri@nortelnetworks.com
Kenneth Sundell Kenneth Sundell
Nortel Networks AB Nortel Networks AB
S:t Eriksgatan 115 A S:t Eriksgatan 115 A
P.O. Box 6701 P.O. Box 6701
SE-113 85 Stockholm Sweden SE-113 85 Stockholm Sweden
ksundell@nortelnetworks.com ksundell@nortelnetworks.com
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