draft-ietf-ccamp-mpls-gmpls-interwork-fmwk-04.txt   draft-ietf-ccamp-mpls-gmpls-interwork-fmwk-05.txt 
Network Working Group K. Shiomoto(Editor) Network Working Group K. Shiomoto(Editor)
Internet Draft (NTT) Internet Draft (NTT)
Intended Status: Informational Intended Status: Informational
Created: September 24, 2007 Created: January 13, 2008
Expires: March 24, 2008 Expires: July 13, 2008
Framework for MPLS-TE to GMPLS migration Framework for MPLS-TE to GMPLS migration
draft-ietf-ccamp-mpls-gmpls-interwork-fmwk-04.txt draft-ietf-ccamp-mpls-gmpls-interwork-fmwk-05.txt
Status of this Memo Status of this Memo
By submitting this Internet-Draft, each author represents that any By submitting this Internet-Draft, each author represents that any
applicable patent or other IPR claims of which he or she is aware 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 becomes have been or will be disclosed, and any of which he or she becomes
aware will be disclosed, in accordance with Section 6 of BCP 79. aware will be disclosed, in accordance with Section 6 of BCP 79.
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
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migrating from MPLS-TE to GMPLS. In the course of migration, MPLS-TE migrating from MPLS-TE to GMPLS. In the course of migration, MPLS-TE
and GMPLS devices, or networks, may coexist which may require and GMPLS devices, or networks, may coexist which may require
interworking between MPLS-TE and GMPLS protocols. Aspects of the interworking between MPLS-TE and GMPLS protocols. Aspects of the
interworking required are discussed as it will influence the choice interworking required are discussed as it will influence the choice
of a migration strategy. This framework document provides a migration of a migration strategy. This framework document provides a migration
toolkit to aid the operator in selection of an appropriate strategy. toolkit to aid the operator in selection of an appropriate strategy.
This framework document also lists a set of solutions that may aid in This framework document also lists a set of solutions that may aid in
interworking, and highlights a set of potential issues. interworking, and highlights a set of potential issues.
draft-ietf-ccamp-mpls-gmpls-interwork-fmwk-04 September 2007 draft-ietf-ccamp-mpls-gmpls-interwork-fmwk-05 January 2008
Table of Contents Table of Contents
1. Introduction.................................................... 2 1. Introduction.................................................... 2
2. Conventions Used in This Document............................... 3 2. Conventions Used in This Document............................... 3
3. Motivations for Migration....................................... 4 3. Motivations for Migration....................................... 4
4. MPLS to GMPLS Migration Models.................................. 4 4. MPLS to GMPLS Migration Models.................................. 4
4.1. Island model............................................... 5 4.1. Island Model............................................... 5
4.1.1. Balanced Islands...................................... 6 4.1.1. Balanced Islands...................................... 6
4.1.2. Unbalanced Islands.................................... 6 4.1.2. Unbalanced Islands.................................... 6
4.2. Integrated model........................................... 7 4.2. Integrated Model........................................... 7
4.3. Phased model............................................... 8 4.3. Phased Model............................................... 8
5. Migration Strategies and Toolkit................................ 8 5. Migration Strategies and Toolkit................................ 8
5.1. Migration Toolkit.......................................... 9 5.1. Migration Toolkit.......................................... 9
5.1.1. Layered Networks...................................... 9 5.1.1. Layered Networks...................................... 9
5.1.2. Routing Interworking................................. 11 5.1.2. Routing Interworking................................. 11
5.1.3. Signaling Interworking............................... 12 5.1.3. Signaling Interworking............................... 12
5.1.4. Path Computation Element............................. 13
6. Manageability Considerations................................... 13 6. Manageability Considerations................................... 13
6.1. Control of Function and Policy............................ 13 6.1. Control of Function and Policy............................ 13
6.2. Information and Data Models............................... 14 6.2. Information and Data Models............................... 14
6.3. Liveness Detection and Monitoring......................... 14 6.3. Liveness Detection and Monitoring......................... 14
6.4. Verifying Correct Operation............................... 14 6.4. Verifying Correct Operation............................... 14
6.5. Requirements on Other Protocols and Functional Components. 14 6.5. Requirements on Other Protocols and Functional Components. 14
6.6. Impact on Network Operation............................... 15 6.6. Impact on Network Operation............................... 15
6.7. Other Considerations...................................... 15 6.7. Other Considerations...................................... 15
7. Security Considerations........................................ 15 7. Security Considerations........................................ 15
8. IANA Considerations............................................ 16 8. IANA Considerations............................................ 16
9. Acknowledgements............................................... 16 9. Acknowledgements............................................... 16
10. Editor's Addresses............................................ 17 10. Editor's Addresses............................................ 16
11. Authors' Addresses............................................ 17 11. Authors' Addresses............................................ 16
12. References.................................................... 18 12. References.................................................... 17
12.1. Normative References..................................... 18 12.1. Normative References..................................... 17
12.2. Informative References................................... 19 12.2. Informative References................................... 18
13. Full Copyright Statement...................................... 19 13. Full Copyright Statement...................................... 19
14. Intellectual Property......................................... 20 14. Intellectual Property......................................... 19
1. Introduction 1. Introduction
Multiprotocol Label Switching Traffic Engineering (MPLS-TE) to Multiprotocol Label Switching Traffic Engineering (MPLS-TE) to
Generalized MPLS (GMPLS) migration is the process of evolving an Generalized MPLS (GMPLS) migration is the process of evolving an
MPLS-TE-based control plane to a GMPLS-based control plane. The MPLS-TE-based control plane to a GMPLS-based control plane. The
network under consideration for migration is, therefore, a packet- network under consideration for migration is, therefore, a packet-
switching network. switching network.
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There are several motivations for such migration, mainly the desire There are several motivations for such migration, mainly the desire
to take advantage of new features and functions added to the GMPLS to take advantage of new features and functions added to the GMPLS
protocols and which are not present in MPLS-TE for packet networks. protocols and which are not present in MPLS-TE for packet networks.
Additionally, before migrating a packet-switching network from MPLS- Additionally, before migrating a packet-switching network from MPLS-
TE to GMPLS, one may choose to first migrate a lower-layer network TE to GMPLS, one may choose to first migrate a lower-layer network
with no control plane (e.g. controlled by a management plane) to with no control plane (e.g. controlled by a management plane) to
using a GMPLS control plane, and this may lead to the desire for using a GMPLS control plane, and this may lead to the desire for
MPLS-TE/GMPLS (transport network) interworking to provide enhanced TE MPLS-TE/GMPLS (transport network) interworking to provide enhanced TE
support and facilitate the later migration of the packet-switching support and facilitate the later migration of the packet-switching
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switching capable (PSC) and non-PSC. Otherwise the term "PSC GMPLS" switching capable (PSC) and non-PSC. Otherwise the term "PSC GMPLS"
or "non-PSC GMPLS" is explicitly used. or "non-PSC GMPLS" is explicitly used.
In general, the term "MPLS" is used to indicate MPLS traffic In general, the term "MPLS" is used to indicate MPLS traffic
engineering (MPLS-TE) only ([RFC3209], [RFC3630], [RFC3784]) and engineering (MPLS-TE) only ([RFC3209], [RFC3630], [RFC3784]) and
excludes other MPLS protocols such as the Label Distribution Protocol excludes other MPLS protocols such as the Label Distribution Protocol
(LDP). TE functionalities of MPLS could be migrated to GMPLS, but (LDP). TE functionalities of MPLS could be migrated to GMPLS, but
non-TE functionalities could not. If non-TE MPLS is intended, it is non-TE functionalities could not. If non-TE MPLS is intended, it is
explicitly indicated. explicitly indicated.
draft-ietf-ccamp-mpls-gmpls-interwork-fmwk-04 September 2007
The reader is assumed to be familiar with the terminology introduced The reader is assumed to be familiar with the terminology introduced
in [RFC3945]. in [RFC3945].
draft-ietf-ccamp-mpls-gmpls-interwork-fmwk-05 January 2008
3. Motivations for Migration 3. Motivations for Migration
Motivations for migration will vary for different service providers. Motivations for migration will vary for different service providers.
This section is presented to provide background so that the migration This section is presented to provide background so that the migration
discussions may be seen in context. Sections 4 and 5 provide examples discussions may be seen in context. Sections 4 and 5 provide examples
to illustrate the migration models and processes. to illustrate the migration models and processes.
Migration of an MPLS-capable LSR to include GMPLS capabilities may be Migration of an MPLS-capable LSR to include GMPLS capabilities may be
performed for one or more reasons, including, not exhaustively: performed for one or more reasons, including, not exhaustively:
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situations described in this document. The interim situations may situations described in this document. The interim situations may
exist for considerable periods of time, but the ultimate objective is exist for considerable periods of time, but the ultimate objective is
not to preserve these situations. For the purposes of this document, not to preserve these situations. For the purposes of this document,
they should be considered as temporary and transitory. they should be considered as temporary and transitory.
4. MPLS to GMPLS Migration Models 4. MPLS to GMPLS Migration Models
Three reference migration models are described below. Multiple Three reference migration models are described below. Multiple
migration models may co-exist in the same network. migration models may co-exist in the same network.
draft-ietf-ccamp-mpls-gmpls-interwork-fmwk-04 September 2007 draft-ietf-ccamp-mpls-gmpls-interwork-fmwk-05 January 2008
4.1. Island model 4.1. Island Model
In the island model, "islands" of network nodes operating one In the island model, "islands" of network nodes operating one
protocol exist within a "sea" of nodes using the other protocol. protocol exist within a "sea" of nodes using the other protocol.
For example, consider an island of GMPLS-capable nodes (PSC) which is For example, consider an island of GMPLS-capable nodes (PSC) which is
introduced into a legacy MPLS network. Such an island might be introduced into a legacy MPLS network. Such an island might be
composed of newly added GMPLS nodes, or might arise from the upgrade composed of newly added GMPLS nodes, or might arise from the upgrade
of existing nodes that previously operated MPLS protocols. of existing nodes that previously operated MPLS protocols.
The opposite is also quite possible. That is, there is a possibility The opposite is also quite possible. That is, there is a possibility
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GMPLS islands are PSC or non-PSC. GMPLS islands are PSC or non-PSC.
Figure 1 shows an example of the island model for MPLS-GMPLS-MPLS Figure 1 shows an example of the island model for MPLS-GMPLS-MPLS
interworking. The model consists of a transit GMPLS island in an MPLS interworking. The model consists of a transit GMPLS island in an MPLS
sea. The nodes at the boundary of the GMPLS island (G1, G2, G5, and sea. The nodes at the boundary of the GMPLS island (G1, G2, G5, and
G6) are referred to as "island border nodes". If the GMPLS island was G6) are referred to as "island border nodes". If the GMPLS island was
non-PSC, all nodes except the island border nodes in the GMPLS-based non-PSC, all nodes except the island border nodes in the GMPLS-based
transit island (G3 and G4) would be non-PSC devices, i.e., optical transit island (G3 and G4) would be non-PSC devices, i.e., optical
equipment (TDM, LSC, and FSC). equipment (TDM, LSC, and FSC).
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................. .......................... .................. ................. .......................... ..................
: MPLS : : GMPLS : : MPLS : : MPLS : : GMPLS : : MPLS :
:+---+ +---+ +----+ +---+ +----+ +---+ +---+: :+---+ +---+ +----+ +---+ +----+ +---+ +---+:
:|R1 |__|R11|___| G1 |_________|G3 |________| G5 |___|R31|__|R3 |: :|R1 |__|R11|___| G1 |_________|G3 |________| G5 |___|R31|__|R3 |:
:+---+ +---+ +----+ +-+-+ +----+ +---+ +---+: :+---+ +---+ +----+ +-+-+ +----+ +---+ +---+:
: ________/ : : _______/ | _____ / : : ________/ : : ________/ : : _______/ | _____ / : : ________/ :
: / : : / | / : : / : : / : : / | / : : / :
:+---+ +---+ +----+ +-+-+ +----+ +---+ +---+: :+---+ +---+ +----+ +-+-+ +----+ +---+ +---+:
:|R2 |__|R21|___| G2 |_________|G4 |________| G6 |___|R41|__|R4 |: :|R2 |__|R21|___| G2 |_________|G4 |________| G6 |___|R41|__|R4 |:
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based on a core infrastructure, but has edge nodes (ingress or based on a core infrastructure, but has edge nodes (ingress or
egress) located in islands of different capabilities. egress) located in islands of different capabilities.
In this case, an LSP starts or ends in a GMPLS (PSC) island and In this case, an LSP starts or ends in a GMPLS (PSC) island and
correspondingly ends or starts in an MPLS island. This mode of correspondingly ends or starts in an MPLS island. This mode of
operation can only be addressed using protocol interworking or operation can only be addressed using protocol interworking or
mapping. Figure 2 shows the reference model for this migration mapping. Figure 2 shows the reference model for this migration
scenario. Head-end and tail-end LSR are in distinct control plane scenario. Head-end and tail-end LSR are in distinct control plane
clouds. clouds.
draft-ietf-ccamp-mpls-gmpls-interwork-fmwk-04 September 2007 draft-ietf-ccamp-mpls-gmpls-interwork-fmwk-05 January 2008
............................ ............................. ............................ .............................
: MPLS : : GMPLS (PSC) : : MPLS : : GMPLS (PSC) :
:+---+ +---+ +----+ +---+ +---+: :+---+ +---+ +----+ +---+ +---+:
:|R1 |________|R11|_______| G1 |________|G3 |________|G5 |: :|R1 |________|R11|_______| G1 |________|G3 |________|G5 |:
:+---+ +---+ +----+ +-+-+ +---+: :+---+ +---+ +----+ +-+-+ +---+:
: ______/ | _____/ : : ______/ | ______/ : : ______/ | _____/ : : ______/ | ______/ :
: / | / : : / | / : : / | / : : / | / :
:+---+ +---+ +----+ +-+-+ +---+: :+---+ +---+ +----+ +-+-+ +---+:
:|R2 |________|R21|_______| G2 |________|G4 |________|G6 |: :|R2 |________|R21|_______| G2 |________|G4 |________|G6 |:
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|<-------------------------------------------------->| |<-------------------------------------------------->|
e2e LSP e2e LSP
Figure 2 : GMPLS-MPLS interworking model. Figure 2 : GMPLS-MPLS interworking model.
It is important to underline that this scenario is also impacted by It is important to underline that this scenario is also impacted by
the directionality of the LSP, and the direction in which the LSP is the directionality of the LSP, and the direction in which the LSP is
established. established.
4.2. Integrated model 4.2. Integrated Model
The second migration model involves a more integrated migration The second migration model involves a more integrated migration
strategy. New devices that are capable of operating both MPLS and strategy. New devices that are capable of operating both MPLS and
GMPLS protocols are introduced into the MPLS network. GMPLS protocols are introduced into the MPLS network.
In the integrated model there are two types of nodes present during In the integrated model there are two types of nodes present during
migration: migration:
- support MPLS only (legacy nodes) - support MPLS only (legacy nodes)
- support MPLS and GMPLS. - support MPLS and GMPLS.
In this model, as existing MPLS devices are upgraded to support both In this model, as existing MPLS devices are upgraded to support both
MPLS and GMPLS, the network continues to operate with a MPLS control MPLS and GMPLS, the network continues to operate with a MPLS control
plane, but some LSRs are also capable of operating with a GMPLS plane, but some LSRs are also capable of operating with a GMPLS
control plane. So, LSPs are provisioned using MPLS protocols where control plane. So, LSPs are provisioned using MPLS protocols where
one end point of a service is a legacy MPLS node and/or where the one end point of a service is a legacy MPLS node and/or where the
selected path between end points traverses a legacy node that is not selected path between end points traverses a legacy node that is not
GMPLS-capable. But where the service can be provided using only GMPLS-capable. But where the service can be provided using only
GMPLS-capable nodes [TE-NODE-CAPS], it may be routed accordingly and GMPLS-capable nodes [RFC5073], it may be routed accordingly and can
can achieve a higher level of functionality by utilizing GMPLS achieve a higher level of functionality by utilizing GMPLS features.
features.
draft-ietf-ccamp-mpls-gmpls-interwork-fmwk-04 September 2007
Once all devices in the network are GMPLS-capable, the MPLS specific Once all devices in the network are GMPLS-capable, the MPLS specific
protocol elements may be turned off, and no new devices need to protocol elements may be turned off, and no new devices need to
support these protocol elements. support these protocol elements.
draft-ietf-ccamp-mpls-gmpls-interwork-fmwk-05 January 2008
In this model, the questions to be addressed concern the co-existence In this model, the questions to be addressed concern the co-existence
of the two protocol sets within the network. Actual interworking is of the two protocol sets within the network. Actual interworking is
not a concern. not a concern.
4.3. Phased model 4.3. Phased Model
The phased model introduces GMPLS features and protocol elements into The phased model introduces GMPLS features and protocol elements into
an MPLS network one by one. For example, some objects or sub-objects an MPLS network one by one. For example, some objects or sub-objects
(such as the ERO label sub-object, [RFC3473]) might be introduced (such as the ERO label sub-object, [RFC3473]) might be introduced
into the signaling used by LSRs that are otherwise MPLS-capable. This into the signaling used by LSRs that are otherwise MPLS-capable. This
would produce a kind of hybrid LSR. would produce a kind of hybrid LSR.
This approach may appear simpler to implement as one is able to This approach may appear simpler to implement as one is able to
quickly and easily pick up key new functions without needing to quickly and easily pick up key new functions without needing to
upgrade the whole protocol implementation. It is most likely to be upgrade the whole protocol implementation. It is most likely to be
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function within a network without the necessity to install and test function within a network without the necessity to install and test
the full GMPLS function. the full GMPLS function.
Interoperability concerns though are exacerbated by this migration Interoperability concerns though are exacerbated by this migration
model, unless all LSRs in the network are updated simultaneously and model, unless all LSRs in the network are updated simultaneously and
there is a clear understanding of which subset of features are to be there is a clear understanding of which subset of features are to be
included in the hybrid LSRs. Interworking between a hybrid LSR and an included in the hybrid LSRs. Interworking between a hybrid LSR and an
unchanged MPLS LSR would put the hybrid LSR in the role of a GMPLS unchanged MPLS LSR would put the hybrid LSR in the role of a GMPLS
LSR as described in the previous sections and puts the unchanged LSR LSR as described in the previous sections and puts the unchanged LSR
in the role of an MPLS LSR. The potential for different hybrids in the role of an MPLS LSR. The potential for different hybrids
within the network will complicate matters considerably. within the network will complicate matters considerably. This model
is, therefore, only appropriate for use when the set of new features
to be deployed is well known and limited, and where there is a clear
understanding of and agreement on this set of features by the network
operators of the ISP(s) involved as well as all vendors whose
equipment will be involved in the migration.
5. Migration Strategies and Toolkit 5. Migration Strategies and Toolkit
An appropriate migration strategy is selected by a network operator An appropriate migration strategy is selected by a network operator
based on factors including the service provider's network deployment based on factors including the service provider's network deployment
plan, customer demand, existing network equipment, operational plan, customer demand, existing network equipment, operational
policy, support from its vendors, etc. policy, support from its vendors, etc.
For PSC networks, the migration strategy involves the selection For PSC networks, the migration strategy involves the selection
between the models described in the previous section. The choice will between the models described in the previous section. The choice will
depend upon the final objective (full GMPLS capability, partial depend upon the final objective (full GMPLS capability, partial
upgrade to include specific GMPLS features, or no change to existing upgrade to include specific GMPLS features, or no change to existing
IP/MPLS networks), and upon the immediate objectives (full, phased, IP/MPLS networks), and upon the immediate objectives (full, phased,
or staged upgrade). or staged upgrade).
draft-ietf-ccamp-mpls-gmpls-interwork-fmwk-04 September 2007
For PSC networks serviced by non-PSC networks, two basic migration For PSC networks serviced by non-PSC networks, two basic migration
strategies can be considered. In the first strategy, the non-PSC strategies can be considered. In the first strategy, the non-PSC
network is made GMPLS-capable, first, and then the PSC network is network is made GMPLS-capable, first, and then the PSC network is
draft-ietf-ccamp-mpls-gmpls-interwork-fmwk-05 January 2008
migrated to GMPLS. This might arise when, in order to expand the migrated to GMPLS. This might arise when, in order to expand the
network capacity, GMPLS-based non-PSC sub-networks are introduced network capacity, GMPLS-based non-PSC sub-networks are introduced
into the legacy MPLS-based networks. Subsequently, the legacy MPLS- into the legacy MPLS-based networks. Subsequently, the legacy MPLS-
based PSC network is migrated to be GMPLS-capable as described in the based PSC network is migrated to be GMPLS-capable as described in the
previous paragraph. Finally the entire network, including both PSC previous paragraph. Finally the entire network, including both PSC
and non-PSC nodes, may be controlled by GMPLS. and non-PSC nodes, may be controlled by GMPLS.
The second strategy for PSC and non-PSC networks is to migrate from The second strategy is to migrate the PSC network to GMPLS first, and
the PSC network to GMPLS, first, and then enable GMPLS within the then enable GMPLS within the non-PSC network. The PSC network is
non-PSC network. The PSC network is migrated as described before, and migrated as described before, and when the entire PSC network is
when the entire PSC network is completely converted to GMPLS, GMPLS- completely converted to GMPLS, GMPLS-based non-PSC devices and
based non-PSC devices and networks may be introduced without any networks may be introduced without any issues of interworking between
issues of interworking between MPLS and GMPLS. MPLS and GMPLS.
These migration strategies and the migration models described in the These migration strategies and the migration models described in the
previous section are not necessarily mutually exclusive. Mixtures of previous section are not necessarily mutually exclusive. Mixtures of
all strategies and models could be applied. The migration models and all strategies and models could be applied. The migration models and
strategies selected will give rise to one or more of the interworking strategies selected will give rise to one or more of the interworking
cases described in the following section. cases described in the following section.
5.1. Migration Toolkit 5.1. Migration Toolkit
As described in the previous sections, an essential part of a As described in the previous sections, an essential part of a
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In the balanced island model, LSP tunnels [RFC4206] are a solution to In the balanced island model, LSP tunnels [RFC4206] are a solution to
carry the end-to-end LSPs across islands of incompatible nodes. carry the end-to-end LSPs across islands of incompatible nodes.
Network layering is often used to separate domains of different data Network layering is often used to separate domains of different data
plane technology. It can also be used to separate domains of plane technology. It can also be used to separate domains of
different control plane technology (such as MPLS and GMPLS different control plane technology (such as MPLS and GMPLS
protocols), and the solutions developed for multiple data plane protocols), and the solutions developed for multiple data plane
technologies can be usefully applied to this situation [RFC3945], technologies can be usefully applied to this situation [RFC3945],
[RFC4206], and [RFC4726]. [MLN-REQ] gives a discussion of the [RFC4206], and [RFC4726]. [MLN-REQ] gives a discussion of the
requirements for multi-layered networks. requirements for multi-layered networks.
draft-ietf-ccamp-mpls-gmpls-interwork-fmwk-04 September 2007 draft-ietf-ccamp-mpls-gmpls-interwork-fmwk-05 January 2008
The GMPLS architecture [RFC3945] identifies three architectural The GMPLS architecture [RFC3945] identifies three architectural
models for supporting multi-layer GMPLS networks, and these models models for supporting multi-layer GMPLS networks, and these models
may be applied to the separation of MPLS and GMPLS control plane may be applied to the separation of MPLS and GMPLS control plane
islands. islands.
- In the peer model, both MPLS and GMPLS nodes run the same routing - In the peer model, both MPLS and GMPLS nodes run the same routing
instance, and routing advertisements from within islands of one instance, and routing advertisements from within islands of one
level of protocol support are distributed to the whole network. level of protocol support are distributed to the whole network.
This is achievable only as described in section 5.1.2 either by This is achievable only as described in section 5.1.2 either by
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required as described for the peer model. required as described for the peer model.
- The border peer architecture model is defined in [MPLS-OVER-GMPLS]. - The border peer architecture model is defined in [MPLS-OVER-GMPLS].
This is a modification of the augmented model where the layer This is a modification of the augmented model where the layer
border routers have visibility into both layers, but no routing border routers have visibility into both layers, but no routing
information is otherwise exchanged between routing protocol information is otherwise exchanged between routing protocol
instances. This architectural model is particularly suited to the instances. This architectural model is particularly suited to the
MPLS-GMPLS-MPLS island model for PSC and non-PSC GMPLS islands. MPLS-GMPLS-MPLS island model for PSC and non-PSC GMPLS islands.
Signaling interworking is required as described for the peer model. Signaling interworking is required as described for the peer model.
draft-ietf-ccamp-mpls-gmpls-interwork-fmwk-04 September 2007 draft-ietf-ccamp-mpls-gmpls-interwork-fmwk-05 January 2008
5.1.2. Routing Interworking 5.1.2. Routing Interworking
Migration strategies may necessitate some interworking between MPLS Migration strategies may necessitate some interworking between MPLS
and GMPLS routing protocols. GMPLS extends the TE information and GMPLS routing protocols. GMPLS extends the TE information
advertised by the IGPs to include non-PSC information and extended advertised by the IGPs to include non-PSC information and extended
PSC information. Because the GMPLS information is provided as PSC information. Because the GMPLS information is provided as
additional TLVs that are carried along with the MPLS information, additional TLVs that are carried along with the MPLS information,
MPLS LSRs are able to "see" all GMPLS LSRs as though they were MPLS MPLS LSRs are able to "see" all GMPLS LSRs as though they were MPLS
PSC LSRs. They will also see other GMPLS information, but will ignore PSC LSRs. They will also see other GMPLS information, but will ignore
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GMPLS nodes. If this issue is addressed, then direct distribution GMPLS nodes. If this issue is addressed, then direct distribution
can be used in all migration models (except the overlay and border can be used in all migration models (except the overlay and border
peer architectural models where the problem does not arise). peer architectural models where the problem does not arise).
- Protocol mapping converts routing advertisements so that they can - Protocol mapping converts routing advertisements so that they can
be received in one protocol and transmitted in the other. For be received in one protocol and transmitted in the other. For
example, a GMPLS routing advertisement could have all of its example, a GMPLS routing advertisement could have all of its
GMPLS-specific information removed and could be flooded as an MPLS GMPLS-specific information removed and could be flooded as an MPLS
advertisement. This mode of interworking would require careful advertisement. This mode of interworking would require careful
standardization of the correct behavior especially where an MPLS standardization of the correct behavior especially where an MPLS
draft-ietf-ccamp-mpls-gmpls-interwork-fmwk-04 September 2007 draft-ietf-ccamp-mpls-gmpls-interwork-fmwk-05 January 2008
advertisement requires default values of GMPLS-specific fields to advertisement requires default values of GMPLS-specific fields to
be generated before the advertisement can be flooded further. be generated before the advertisement can be flooded further.
There is also considerable risk of confusion in closely meshed There is also considerable risk of confusion in closely meshed
networks where many LSRs have MPLS and GMPLS capable interfaces. networks where many LSRs have MPLS and GMPLS capable interfaces.
This option for routing interworking during migration is NOT This option for routing interworking during migration is NOT
RECOMMENDED for any migration model. Note that converting GMPLS- RECOMMENDED for any migration model. Note that converting GMPLS-
specific sub-TLVs to MPLS-specific ones but not stripping the specific sub-TLVs to MPLS-specific ones but not stripping the
GMPLS-specific ones is considered as a variant of the proposed GMPLS-specific ones is considered as a variant of the proposed
solution in the previous bullet (Unknown sub-TLVs should be solution in the previous bullet (Unknown sub-TLVs should be
skipping to change at page 13, line 4 skipping to change at page 13, line 4
bidirectional LSPs. bidirectional LSPs.
Note that tunneling and stitching are not available in unbalanced Note that tunneling and stitching are not available in unbalanced
island models because in these cases the LSP end points use island models because in these cases the LSP end points use
different protocols. different protocols.
- Protocol mapping is the conversion of signaling messages between - Protocol mapping is the conversion of signaling messages between
MPLS and GMPLS. This mechanism requires careful documentation of MPLS and GMPLS. This mechanism requires careful documentation of
the protocol fields and how they are mapped. This is relatively the protocol fields and how they are mapped. This is relatively
straightforward in the MPLS-GMPLS unbalanced island model for LSPs straightforward in the MPLS-GMPLS unbalanced island model for LSPs
draft-ietf-ccamp-mpls-gmpls-interwork-fmwk-04 September 2007 draft-ietf-ccamp-mpls-gmpls-interwork-fmwk-05 January 2008
signaled in the MPLS-GMPLS direction. However, it may be more signaled in the MPLS-GMPLS direction. However, it may be more
complex for LSPs signaled in the opposite direction, and this will complex for LSPs signaled in the opposite direction, and this will
lead to considerable complications for providing GMPLS services lead to considerable complications for providing GMPLS services
over the MPLS island and for terminating those services at an over the MPLS island and for terminating those services at an
egress LSR that is not GMPLS-capable. Further, in balanced island egress LSR that is not GMPLS-capable. Further, in balanced island
models, and in particular where there are multiple small models, and in particular where there are multiple small
(individual node) islands, the repeated conversion of signaling (individual node) islands, the repeated conversion of signaling
parameters may lead to loss of information (and functionality) or parameters may lead to loss of information (and functionality) or
mis-requests. mis-requests.
- Ships in the night could be used in the integrated migration model - Ships in the night could be used in the integrated migration model
to allow MPLS-capable LSRs to establish LSPs using MPLS signaling to allow MPLS-capable LSRs to establish LSPs using MPLS signaling
protocols and GMPLS LSRs to establish LSPs using GMPLS signaling protocols and GMPLS LSRs to establish LSPs using GMPLS signaling
protocols. LSRs that can handle both sets of protocols could work protocols. LSRs that can handle both sets of protocols could work
with both types of LSRs, and no conversion of protocols would be with both types of LSRs, and no conversion of protocols would be
needed. needed.
5.1.4. Path Computation Element
The Path Computation Element (PCE) [RFC4655] may provide an
additional tool to aid MPLS to GMPLS migration. If a layered network
approach (Section 5.1.1) is used, PCEs may be used to facilitate the
computation of paths for LSPs in the different layers
[PCE-INTER-LAYER].
6. Manageability Considerations 6. Manageability Considerations
Attention should be given during migration planning to how the Attention should be given during migration planning to how the
network will be managed during and after migration. For example, will network will be managed during and after migration. For example, will
the LSRs of different protocol capabilities be managed separately or the LSRs of different protocol capabilities be managed separately or
as one management domain. For example, in the Island Model, it is as one management domain. For example, in the Island Model, it is
possible to consider managing islands of one capability separately possible to consider managing islands of one capability separately
from the surrounding sea. In the case of islands that have different from the surrounding sea. In the case of islands that have different
switching capabilities, it is possible that the islands already have switching capabilities, it is possible that the islands already have
separate management in place before the migration: the resultant separate management in place before the migration: the resultant
skipping to change at page 14, line 5 skipping to change at page 14, line 5
moment of changeover between different levels of protocol support. moment of changeover between different levels of protocol support.
Such a change may be made without service halt or during a period of Such a change may be made without service halt or during a period of
network maintenance. network maintenance.
Where island boundaries exist, it must be possible to manage the Where island boundaries exist, it must be possible to manage the
relationships between protocols and to indicate which interfaces relationships between protocols and to indicate which interfaces
support which protocols on a border LSR. Further, island borders are support which protocols on a border LSR. Further, island borders are
a natural place to apply policy, and management should allow a natural place to apply policy, and management should allow
configuration of such policies. configuration of such policies.
draft-ietf-ccamp-mpls-gmpls-interwork-fmwk-04 September 2007 draft-ietf-ccamp-mpls-gmpls-interwork-fmwk-05 January 2008
6.2. Information and Data Models 6.2. Information and Data Models
No special information or data models are required to support No special information or data models are required to support
migration, but note that migration in the control plane implies migration, but note that migration in the control plane implies
migration from MPLS management tools to GMPLS management tools. migration from MPLS management tools to GMPLS management tools.
During migration, therefore, it may be necessary for LSRs and During migration, therefore, it may be necessary for LSRs and
management applications to support both MPLS and GMPLS management management applications to support both MPLS and GMPLS management
data. data.
skipping to change at page 15, line 5 skipping to change at page 15, line 5
has been observed, the management components may need to migrate in has been observed, the management components may need to migrate in
step with the control plane components, but this does not impact the step with the control plane components, but this does not impact the
management protocols, just the data that they carry. management protocols, just the data that they carry.
It should also be observed that providing signaling and routing It should also be observed that providing signaling and routing
connectivity across a migration island in support of a layered connectivity across a migration island in support of a layered
architecture may require the use of protocol tunnels (such as GRE) architecture may require the use of protocol tunnels (such as GRE)
between island border nodes. Such tunnels may impose additional between island border nodes. Such tunnels may impose additional
configuration requirements at the border nodes. configuration requirements at the border nodes.
draft-ietf-ccamp-mpls-gmpls-interwork-fmwk-04 September 2007 draft-ietf-ccamp-mpls-gmpls-interwork-fmwk-05 January 2008
6.6. Impact on Network Operation 6.6. Impact on Network Operation
The process of migration is likely to have significant impact on The process of migration is likely to have significant impact on
network operation while migration is in progress. The main objective network operation while migration is in progress. The main objective
of migration planning should be to reduce the impact on network of migration planning should be to reduce the impact on network
operation and on the services perceived by the network users. operation and on the services perceived by the network users.
To this end, planners should consider reducing the number of To this end, planners should consider reducing the number of
migration steps that they perform, and minimizing the number of migration steps that they perform, and minimizing the number of
skipping to change at page 16, line 4 skipping to change at page 16, line 4
even though these island boundaries might lie within an IGP area or even though these island boundaries might lie within an IGP area or
AS. AS.
No changes are proposed to the security procedures built into MPLS No changes are proposed to the security procedures built into MPLS
and GMPLS signaling and routing. GMPLS signaling and routing inherit and GMPLS signaling and routing. GMPLS signaling and routing inherit
their security mechanisms from MPLS signaling and routing without any their security mechanisms from MPLS signaling and routing without any
changes. Hence, there will be no additional issues with security in changes. Hence, there will be no additional issues with security in
interworking scenarios. Further, since the MPLS and GMPLS signaling interworking scenarios. Further, since the MPLS and GMPLS signaling
and routing security is provided on a hop-by-hop basis, and since all and routing security is provided on a hop-by-hop basis, and since all
signaling and routing exchanges described in this document for use signaling and routing exchanges described in this document for use
draft-ietf-ccamp-mpls-gmpls-interwork-fmwk-04 September 2007 draft-ietf-ccamp-mpls-gmpls-interwork-fmwk-05 January 2008
between any pair of LSRs are based on either MPLS or GMPLS, there are between any pair of LSRs are based on either MPLS or GMPLS, there are
no changes necessary to the security procedures. no changes necessary to the security procedures.
8. IANA Considerations 8. IANA Considerations
This informational framework document makes no requests for IANA This informational framework document makes no requests for IANA
action. action.
9. Acknowledgements 9. Acknowledgements
The authors are grateful to Daisaku Shimazaki for discussion during The authors are grateful to Daisaku Shimazaki for discussion during
initial work on this document. The authors are grateful to Dean Cheng initial work on this document. The authors are grateful to Dean Cheng
and Adrian Farrel for their valuable comments. and Adrian Farrel for their valuable comments.
draft-ietf-ccamp-mpls-gmpls-interwork-fmwk-04 September 2007
10. Editor's Addresses 10. Editor's Addresses
Kohei Shiomoto, Editor Kohei Shiomoto, Editor
NTT NTT
Midori 3-9-11 Midori 3-9-11
Musashino, Tokyo 180-8585, Japan Musashino, Tokyo 180-8585, Japan
Phone: +81 422 59 4402 Phone: +81 422 59 4402
Email: shiomoto.kohei@lab.ntt.co.jp Email: shiomoto.kohei@lab.ntt.co.jp
11. Authors' Addresses 11. Authors' Addresses
skipping to change at page 17, line 39 skipping to change at page 16, line 52
Phone: +33 2 96 05 30 20 Phone: +33 2 96 05 30 20
Email: jeanlouis.leroux@orange-ftgroup.com Email: jeanlouis.leroux@orange-ftgroup.com
Deborah Brungard Deborah Brungard
AT&T AT&T
Rm. D1-3C22 - 200 S. Laurel Ave. Rm. D1-3C22 - 200 S. Laurel Ave.
Middletown, NJ 07748, USA Middletown, NJ 07748, USA
Phone: +1 732 420 1573 Phone: +1 732 420 1573
Email: dbrungard@att.com Email: dbrungard@att.com
Zafar Alli
Cisco Systems, Inc.
EMail: zali@cisco.com
draft-ietf-ccamp-mpls-gmpls-interwork-fmwk-05 January 2008
Kenji Kumaki Kenji Kumaki
KDDI Corporation KDDI Corporation
Garden Air Tower Garden Air Tower
Iidabashi, Chiyoda-ku, Iidabashi, Chiyoda-ku,
Tokyo 102-8460, JAPAN Tokyo 102-8460, JAPAN
Phone: +81-3-6678-3103 Phone: +81-3-6678-3103
Email: ke-kumaki@kddi.com Email: ke-kumaki@kddi.com
Zafar Alli
Cisco Systems, Inc.
EMail: zali@cisco.com
Eiji Oki Eiji Oki
NTT NTT
Midori 3-9-11 Midori 3-9-11
Musashino, Tokyo 180-8585, Japan Musashino, Tokyo 180-8585, Japan
Phone: +81 422 59 3441 Phone: +81 422 59 3441
Email: oki.eiji@lab.ntt.co.jp Email: oki.eiji@lab.ntt.co.jp
draft-ietf-ccamp-mpls-gmpls-interwork-fmwk-04 September 2007
Ichiro Inoue Ichiro Inoue
NTT NTT
Midori 3-9-11 Midori 3-9-11
Musashino, Tokyo 180-8585, Japan Musashino, Tokyo 180-8585, Japan
Phone: +81 422 59 3441 Phone: +81 422 59 3441
Email: inoue.ichiro@lab.ntt.co.jp Email: inoue.ichiro@lab.ntt.co.jp
Tomohiro Otani Tomohiro Otani
KDDI Laboratories KDDI Laboratories
skipping to change at page 18, line 40 skipping to change at page 18, line 5
Engineering (RSVP-TE) Extensions ", RFC 3473, January 2003. Engineering (RSVP-TE) Extensions ", RFC 3473, January 2003.
[RFC3630] Katz, D., Kompella, K., and D. Yeung, "Traffic Engineering [RFC3630] Katz, D., Kompella, K., and D. Yeung, "Traffic Engineering
(TE) Extensions to OSPF Version 2", RFC 3630, September (TE) Extensions to OSPF Version 2", RFC 3630, September
2003. 2003.
[RFC3784] Smit, H. and T. Li, "Intermediate System to Intermediate [RFC3784] Smit, H. and T. Li, "Intermediate System to Intermediate
System (IS-IS) Extensions for Traffic Engineering (TE)", System (IS-IS) Extensions for Traffic Engineering (TE)",
RFC 3784, June 2004. RFC 3784, June 2004.
draft-ietf-ccamp-mpls-gmpls-interwork-fmwk-05 January 2008
[RFC3945] Mannie, E., "Generalized Multi-Protocol Label Switching [RFC3945] Mannie, E., "Generalized Multi-Protocol Label Switching
Architecture", RFC 3945, October 2004. Architecture", RFC 3945, October 2004.
[RFC4872] Lang, J. P., Rekhter, Y., Papadimitriou, D. (Editors), " [RFC4872] Lang, J. P., Rekhter, Y., Papadimitriou, D. (Editors), "
RSVP-TE Extensions in support of End-to-End Generalized RSVP-TE Extensions in support of End-to-End Generalized
Multi-Protocol Label Switching (GMPLS)-based Recovery", Multi-Protocol Label Switching (GMPLS)-based Recovery",
RFC4872, May 2007. RFC4872, May 2007.
[RFC4873] Berger, L., Bryskin, I., Papadimitriou, D., Farrel, A., [RFC4873] Berger, L., Bryskin, I., Papadimitriou, D., Farrel, A.,
"GMPLS Based Segment Recovery", RFC 4873, May 2007. "GMPLS Based Segment Recovery", RFC 4873, May 2007.
draft-ietf-ccamp-mpls-gmpls-interwork-fmwk-04 September 2007 [RFC5073] Vasseur, Le Roux, editors, "IGP Routing Protocol
[TE-NODE-CAPS] Vasseur, Le Roux, editors " IGP Routing Protocol
Extensions for Discovery of Traffic Engineering Node Extensions for Discovery of Traffic Engineering Node
Capabilities", draft-ietf-ccamp-te-node-cap, work in Capabilities", RFC 5073, Decemer 2007.
progress.
12.2. Informative References 12.2. Informative References
[RFC4206] Kompella, K., and Rekhter, Y., "Label Switched Paths (LSP) [RFC4206] Kompella, K., and Rekhter, Y., "Label Switched Paths (LSP)
Hierarchy with Generalized Multi-Protocol Label Switching Hierarchy with Generalized Multi-Protocol Label Switching
(GMPLS) Traffic Engineering (TE)", RFC 4206, October 2005. (GMPLS) Traffic Engineering (TE)", RFC 4206, October 2005.
[RFC4655] A. Farrel, JP. Vasseur and J. Ash, "A Path Computation
Element (PCE)-Based Architecture", RFC 4655, August 2006.
[RFC4726] Farrel, A., Vasseur, J.P., Ayyangar, A., " A Framework for
Inter-Domain Multiprotocol Label Switching Traffic
Engineering", RFC4726, November 2006.
[MLN-REQ] Shiomoto, K., Papadimitriou, D., Le Roux, J.L., Vigoureux, [MLN-REQ] Shiomoto, K., Papadimitriou, D., Le Roux, J.L., Vigoureux,
M., Brungard, D., "Requirements for GMPLS-based multi- M., Brungard, D., "Requirements for GMPLS-based multi-
region and multi-layer networks (MRN/MLN)", draft-ietf- region and multi-layer networks (MRN/MLN)", draft-ietf-
ccamp-gmpls-mln-reqs, work in progress. ccamp-gmpls-mln-reqs, work in progress.
[MPLS-OVER-GMPLS] Kumaki, K., et al., " Interworking Requirements to
Support operation of MPLS-TE over GMPLS networks", draft-
ietf-ccamp-mpls-gmpls-interwork-reqts, work in progress.
[PCE-INTER-LAYER] Oki, E., Le Roux , J-L,. and Farrel, A., "Framework
for PCE-Based Inter-Layer MPLS and GMPLS Traffic
Engineering," draft-ietf-pce-inter-layer-frwk, work in
progress.
[STITCH] Ayyangar, A., Vasseur, JP. "Label Switched Path Stitching [STITCH] Ayyangar, A., Vasseur, JP. "Label Switched Path Stitching
with Generalized MPLS Traffic Engineering", draft-ietf- with Generalized MPLS Traffic Engineering", draft-ietf-
ccamp-lsp-stitching, work in progress. ccamp-lsp-stitching, work in progress.
[RFC4726] Farrel, A., Vasseur, J.P., Ayyangar, A., " A Framework for draft-ietf-ccamp-mpls-gmpls-interwork-fmwk-05 January 2008
Inter-Domain Multiprotocol Label Switching Traffic
Engineering", RFC4726, November 2006.
[MPLS-OVER-GMPLS] Kumaki, K., et al., " Interworking Requirements to
Support operation of MPLS-TE over GMPLS networks", draft-
ietf-ccamp-mpls-gmpls-interwork-reqts, work in progress.
13. Full Copyright Statement 13. Full Copyright Statement
Copyright (C) The IETF Trust (2007). Copyright (C) The IETF Trust (2008).
This document is subject to the rights, licenses and restrictions This document is subject to the rights, licenses and restrictions
contained in BCP 78, and except as set forth therein, the authors contained in BCP 78, and except as set forth therein, the authors
retain all their rights. retain all their rights.
This document and the information contained herein are provided on an This document and the information contained herein are provided on an
"AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND
THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS
OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF
THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
draft-ietf-ccamp-mpls-gmpls-interwork-fmwk-04 September 2007
14. Intellectual Property 14. Intellectual Property
The IETF takes no position regarding the validity or scope of any The IETF takes no position regarding the validity or scope of any
Intellectual Property Rights or other rights that might be claimed to Intellectual Property Rights or other rights that might be claimed to
pertain to the implementation or use of the technology described in pertain to the implementation or use of the technology described in
this document or the extent to which any license under such rights this document or the extent to which any license under such rights
might or might not be available; nor does it represent that it has might or might not be available; nor does it represent that it has
made any independent effort to identify any such rights. Information made any independent effort to identify any such rights. Information
on the procedures with respect to rights in RFC documents can be on the procedures with respect to rights in RFC documents can be
found in BCP 78 and BCP 79. found in BCP 78 and BCP 79.
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