Internet Engineering Task Force R. Martinotti Internet-Draft D. Caviglia Intended status: Informational Ericsson Expires: May 21, 2009 N. Sprecher Nokia Siemens Networks November 17, 2008 Interworking between MPLS-TP and IP/MPLS draft-martinotti-mpls-tp-interworking-00 Status of this Memo By submitting this Internet-Draft, each author represents that 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 becomes aware will be disclosed, in accordance with Section 6 of BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet- Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. This Internet-Draft will expire on May 21, 2009. Abstract Purpose of this ID is to illustrate interworking scenarios between network(s) supporting MPLS-TP and network(s) supporting IP/MPLS. Main inteworking issues and open points are highlighted. Martinotti, et al. Expires May 21, 2009 [Page 1] Internet-Draft draft-martinotti-mpst-tp-interworking-00 November 2008 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.1. Background . . . . . . . . . . . . . . . . . . . . . . . . 3 1.2. Scope of this document . . . . . . . . . . . . . . . . . . 3 2. Conventions used in this document . . . . . . . . . . . . . . 3 3. Acronyms . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 4. Problem Statement . . . . . . . . . . . . . . . . . . . . . . 4 5. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4 5.1. Network Layering . . . . . . . . . . . . . . . . . . . . . 5 5.2. Network Partitioning . . . . . . . . . . . . . . . . . . . 6 6. Elements used in the figures . . . . . . . . . . . . . . . . . 6 7. Network Decomposition . . . . . . . . . . . . . . . . . . . . 7 7.1. Network Layering . . . . . . . . . . . . . . . . . . . . . 7 7.1.1. Ethernet encapsulation over MPLS-TP . . . . . . . . . 7 7.1.2. IP/MPLS encapsulation over MPLS-TP . . . . . . . . . . 10 7.1.2.1. IP/MPLS does not require PHP from MPLS-TP . . . . 10 7.1.2.2. IP/MPLS requires PHP from MPLS-TP . . . . . . . . 13 7.2. Network Partitioning . . . . . . . . . . . . . . . . . . . 15 7.2.1. Border Equipment . . . . . . . . . . . . . . . . . . . 15 7.2.1.1. Multisegment Pseudowire . . . . . . . . . . . . . 16 7.2.1.2. LSP stitching . . . . . . . . . . . . . . . . . . 18 7.2.2. Border Link . . . . . . . . . . . . . . . . . . . . . 20 7.2.2.1. Multisegment Pseudowire . . . . . . . . . . . . . 20 7.2.2.2. LSP stitching . . . . . . . . . . . . . . . . . . 23 8. Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . 25 9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 25 10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 25 11. Security Considerations . . . . . . . . . . . . . . . . . . . 25 12. References . . . . . . . . . . . . . . . . . . . . . . . . . . 25 12.1. Normative References . . . . . . . . . . . . . . . . . . . 25 12.2. Informative References . . . . . . . . . . . . . . . . . . 25 Appendix A. Additional Stuff . . . . . . . . . . . . . . . . . . 26 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 26 Intellectual Property and Copyright Statements . . . . . . . . . . 27 Martinotti, et al. Expires May 21, 2009 [Page 2] Internet-Draft draft-martinotti-mpst-tp-interworking-00 November 2008 1. Introduction 1.1. Background MPLS-TP is a joint ITU-IETF effort to include a MPLS Transport Profile within the IETF MPLS architecture to support the capabilities and functionalities of a packet transport network as defined by ITU-T. In the MPLS-TP requirements [draftjenkins] it is highlighted that an MPLS-TP architecture must allow interworking with new and already deployed IP/MPLS networks. ... 1.2. Scope of this document This document illustrates the most likely interworking scenarios between MPLS-TP and IP/MPLS. For each of the examined scenario interworking limitations, issues and open points, with particular focus on OAM capabilities, are provided. The main architectural construct considered in this document foresees PWE3 Protocol Stack Reference Model, however also MPLS Protocol Stack Reference Model is presented. See [draftblb] for details. 2. Conventions used in this document The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC 2119]. 3. Acronyms AC Attachment circuit CE Customer Edge CLI Client ETH Ethernet MAC Layer ETY Ethernet Physical Layer IWF Interworking Function Martinotti, et al. Expires May 21, 2009 [Page 3] Internet-Draft draft-martinotti-mpst-tp-interworking-00 November 2008 LER Label Edge Router LSP Label Switched Path LSR Label Switch Router MAC Media Access Control MEP Maintenance Association End Point MIP Maintenance Association Intermediate Point MS-PW Multi Segment PW NE Network Element OAM Operations, Administration and Maintenance PE Provider Edge PSN Packet Switched Network PW Pseudowire SRV Server SS-PW Single Segment PW 4. Problem Statement The problem this document is addressing is the network scenarios in which a MPLS-TP network can be interconnected with a IP/MPLS network in different ways, such that the network decomposition can envisage network layering and/or network partitioning. The presented scenarios are not intended to be comprehensive, for instance more complex scenarios can be created composing those presented in this document. 5. Terminology As far as this document is concerned, the following terminology is used: o MPLS-TP NE: a NE that supports MPLS-TP functions Martinotti, et al. Expires May 21, 2009 [Page 4] Internet-Draft draft-martinotti-mpst-tp-interworking-00 November 2008 o MPLS-TP Network: a network in which MPLS-TP NEs are deployed o IP/MPLS NE: a NE that supports IP/MPLS functions o IP/MPLS Network: a network in which IP/MPLS NEs are deployed For each of the scenarios described in this document, there are two paragraphs, one related to possible issues already envisaged by the authors (Open Issues), the other related to aspects still left for furthr study and/or definition (open Points). This Section provides some terminology about network layering and partitioning. Primarily source of those definitions is [ITU-T G.805]. Readers already familiar with these concepts can skip this Section. 5.1. Network Layering The following figure illustrates the Network Layering concept: ____ ___ ___ __ _/ \___/ \ _/ \___/ \_ / \__ / \__ /===================\===+ +====/==================\ | |___O------------------O___| | \ /\__/_ _ _ _ _ _ _ _ _ _\__/\ / \ ___ __ / \/ \/ \ ___ _ / \_/ \____/ \_/ | | \_/ \___/ \_/ Layer n | | Layer n | __ __ | | _/ \__/ \ | | / \__ | | / \ | +-0| |0-+ \ / \ __ _ / \_/ \_/ \__/ Layer n-1 Network Layering Figure 1 Layer n is carried over Layer n-1. Some reader will also call this concept "Overlay model". Martinotti, et al. Expires May 21, 2009 [Page 5] Internet-Draft draft-martinotti-mpst-tp-interworking-00 November 2008 5.2. Network Partitioning The following figure illustrates the Network Partitioning concept: ___ ___ ____ ____ ___ ___ _/ \___/ \ _/ \__ _/ \___/ \ _/ \__ / \__/ \ / \__/ \_ / \ | / \ | Sub-Network Domain 1 |+++++| Sub-Network Domain 2 | \ / | \ / \ __ ___ __ _/ \ ___ ___ __ _/ \_/ \____/ \___/ \____/ \_/ \____/ \___/ \___/ Network Partitioning Figure 2 The boundary between the two subnetworks can be a link (as defined by [ITU-T G.805]), but also a node, which in this case SHALL be able to handle the technologies of both subnetworks. The two subnetworks are at the same level. Some reader will also call this concept "Peer model". 6. Elements used in the figures A legenda of the symbols, which are most used in the following Sections, is provided, in order to facilitate compreension of the scenarios. Martinotti, et al. Expires May 21, 2009 [Page 6] Internet-Draft draft-martinotti-mpst-tp-interworking-00 November 2008 Equipment: ----- Direct connection - - - Virtual connection ..... one or more direct connections Layers: | Termination + Connection <-> Stitching OAM: > or < MEP O MIP Figure 3 7. Network Decomposition This Section provides some interworking scenarios, using the concepts described in Section 5. 7.1. Network Layering In the rest of this Section the following roles applies: o Customer network is carried over IP/MPLS (e.g. via PW encapsulation) o IP/MPLS network is client of MPLS-TP subnetwork o MPLS-TP subnetwork is deployed over Ethernet, other server layers are possible (not shown in this document) 7.1.1. Ethernet encapsulation over MPLS-TP In this scenario the physical interface between the IP/MPLS and the MPLS-TP network is Ethernet; the interworking is done via Ethernet frame encapsulation in PW over MPLS-TP (as per PWE3 Protocol Stack Reference Model). The following figure illustrates the functional interworking among the networks: Martinotti, et al. Expires May 21, 2009 [Page 7] Internet-Draft draft-martinotti-mpst-tp-interworking-00 November 2008 Networks: Customer Network +---+ - - - - - - - - - - - - - - - - - - - - - - - - - +---+ | _________________________________________________ | |/ IP/MPLS Network \| +---------------+ - - - - - - - - - +---------------+ ^ \______________|___________________|______________/ PW emulation | _________________ | |/ MPLS-TP Network \| +-------------------+ ^ \_________________/ VPWS Equipment: +++++ +++++ + 1 +----+ - - - - - - - - - - - - - - - - - - - - - - - +----+ 9 + +++++ | | +++++ CE +++++ +++++ +++++ +++++ CE + 2 +...+ 3 +-----+- - - - - - - -+-----+ 7 +...+ 8 + +++++ +++++ | | +++++ +++++ LER LSR +++++ +++++ +++++ LSR LER PE CE + 4 +...+ 5 +...+ 6 + PE +++++ +++++ +++++ LER LSR LER PE PE Ethernet encapsulation - Networks view Figure 4 The LSR 3 and 7 are one hop away from the IP/MPLS layer point of view, thus there is no interaction between the control plane of IP/ MPLS and MPLS-TP. The service provided by the MPLS-TP network is an E-Line service realized via VPWS, thus the LER4 and 6 are unaware that above the Ethernet layer there is a MPLS LSP. The following figure illustrates the stacking relationship among the technology layers and OAM relationship among the networks: Martinotti, et al. Expires May 21, 2009 [Page 8] Internet-Draft draft-martinotti-mpst-tp-interworking-00 November 2008 Layers: |--------+----------------------CLI----------------------+--------| |--SRV--| |---------------------PW----------------------| |--SRV--| |------+--------------LSP--------------+------| |-ETH-| |------+------ETH------+------| |-ETH-| |-ETY-| |-ETY-| |-----PW------| |-ETY-| |-ETY-| |-----LSP-----| |-ETH-| |-ETH-| |-ETY-| |-ETY-| OAM: (9) >----O-------------------------------------------------O----< CLI (8) >-----------------------------------------------< CLI (7) >-------------------------------------------< PW (6) >------O-----------------------------O------< LSP (5) >----O-----------------O----< ETH (4) >O-------------O< ETH (3) >-----------< PW (2) >-----------< LSP (1) > -< > - < >---< > - < > - < >---< > - < >- < PHY Equipment: +++++ +++++ +++++ +++++ +++++ +++++ +++++ +++++ +++++ + 1 +--+ 2 +...+ 3 +---+ 4 +...+ 5 +...+ 6 +---+ 7 +...+ 8 +--+ 9 + +++++ +++++ +++++ +++++ +++++ +++++ +++++ +++++ +++++ CE LER LSR LER LSR LER LSR LER CE Ethernet encapsulation - Layers and OAM view Figure 5 Several levels of OAM are shown in the previous figure, these are not comprehensive (e.g. Ethernet OAM defines several levels for each layer), any subset of them MAY be configured in a network. A brief description of the different levels is provided: (9) End-to-End Client level OAM on Client network (8) Edge-to-Edge Client level OAM on IP/MPLS network (7) Edge-to-Edge MPLS OAM on IP/MPLS network (at PW level) (6) Edge-to-Edge MPLS OAM on IP/MPLS network (at LSP level) Martinotti, et al. Expires May 21, 2009 [Page 9] Internet-Draft draft-martinotti-mpst-tp-interworking-00 November 2008 (5) Router-to-Router Eth OAM on IP/MPLS network (4) Edge-to-Edge Eth OAM on MPLS-TP network (3) Edge-to-Edge MPLS OAM on MPLS-TP network (at PW level) (2) Edge-to-Edge MPLS OAM on MPLS-TP network (at LSP level) (1) Physical level OAM (MAY be of several kind) Note that the OAM layers not directly related to MPLS-TP network have been reported just for completeness of the scenario, however their behaviour and interworking are out of scope of this document. Open Issues: o None up to now Open Points: o Inteworking between LSP OAM (2) and ETH OAM (3) and/or (4) is still to be cleared/defined 7.1.2. IP/MPLS encapsulation over MPLS-TP In this scenario the physical interface between the IP/MPLS and the MPLS-TP network MAY be Ethernet; the interworking is done via client LSP encapsulation over MPLS-TP (as per MPLS Protocol Stack Reference Model). The following main features SHOULD be taken into account: o Interaction at Data Plane o Possible support of Management Plane of client MPLS Layer o Possible support of Control Plane of client MPLS Layer o Possible handling of PHP of client MPLS Layer 7.1.2.1. IP/MPLS does not require PHP from MPLS-TP In this scenario the edge nodes of the MPLS-TP subnetwork are one hop away from no client node (of the IP/MPLS network) requiring PHP. The following figure illustrates the functional interworking among the networks. Martinotti, et al. Expires May 21, 2009 [Page 10] Internet-Draft draft-martinotti-mpst-tp-interworking-00 November 2008 IP/MPLS network does not require PHP from MPLS-TP Networks: Customer Network +---+ - - - - - - - - - - - - - - - - - - - - - - - - - +---+ | _________________________________________________ | |/ IP/MPLS Network \| +---------------+ - - - - - - - - - +---------------+ ^ \______________|___________________|______________/ PW emulation | _________________ | |/ MPLS-TP Network \| +-------------------+ ^ \_________________/ MPLS VPN Equipment: +++++ +++++ + 1 +----+ - - - - - - - - - - - - - - - - - - - - - - - +----+ 9 + +++++ | | +++++ CE +++++ +++++ +++++ +++++ +++++ +++++ CE + 2 +...+ 3 +---+ +- - - - - -+ +---+ 7 +...+ 8 + +++++ +++++ + + + + +++++ +++++ LER LSR +LSR+ +++++ +LSR+ LSR LER PE + 4 +...+ 5 +...+ 6 + PE +++++ +++++ +++++ LER LSR LER IP/MPLS encapsulation over MPLS-TP - Networks view Figure 6 The equipment 4 and 6 in the above figure act as dual function: o LSR of client IP/MPLS network o LER of server MPLS-TP subnetwork The following figure illustrates the stacking relationship among the technology layers and OAM relationship among the networks: Martinotti, et al. Expires May 21, 2009 [Page 11] Internet-Draft draft-martinotti-mpst-tp-interworking-00 November 2008 IP/MPLS network does not require PHP from MPLS-TP Layers: |--------+----------------------CLI----------------------+--------| |--SRV--| |---------------------PW----------------------| |--SRV--| |------+-------+------LSP------+-------+------| |-ETH-| |-ETH-| |-----LSP-----| |-ETH-| |-ETH-| |-ETY-| |-ETY-| |-ETH-| |-ETH-| |-ETY-| |-ETY-| |-ETY-| |-ETY-| OAM: (6) >----O-------------------------------------------------O----< CLI (5) >-----------------------------------------------< CLI (4) >-------------------------------------------< PW (3) >--------------O-------------O--------------< LSP (2) >-----------< LSP (1) >--< > - < >---< > - < > - < >---< > - < >--< PHY Equipment: +++++ +++++ +++++ +++++ +++++ +++++ +++++ +++++ +++++ + 1 +--+ 2 +...+ 3 +---+ 4 +...+ 5 +...+ 6 +---+ 7 +...+ 8 +--+ 9 + +++++ +++++ +++++ +++++ +++++ +++++ +++++ +++++ +++++ CE LER LSR LER LSR LER LSR LER CE IP/MPLS encapsulation over MPLS-TP - Layers and OAM view Figure 7 A not comprehensive set of OAM is shown in the previous figure, the same generic assumptions as in Section 7.1.1 are considered. A brief description of the different levels is provided: (6) End-to-End Client level OAM on Client network (5) Edge-to-Edge Client level OAM on IP/MPLS network (4) Edge-to-Edge MPLS OAM on IP/MPLS network (at PW level) (3) Edge-to-Edge MPLS OAM on IP/MPLS network (at LSP level) (2) Edge-to-Edge MPLS OAM on MPLS-TP network (at LSP level) (1) Physical level OAM (MAY be of several kind) Open Issues: o None up to now Open Points: Martinotti, et al. Expires May 21, 2009 [Page 12] Internet-Draft draft-martinotti-mpst-tp-interworking-00 November 2008 o Inteworking between LSP OAM (2) and LSP OAM (3) is still to be cleared/defined 7.1.2.2. IP/MPLS requires PHP from MPLS-TP In this scenario the edge nodes of the MPLS-TP subnetwork are one hop away from at least one client node (of the IP/MPLS network) requiring PHP. The following figure illustrates the functional interworking among the networks: IP/MPLS requires PHP from MPLS-TP Networks: Customer Network +---+ - - - - - - - - - - - - - - - - - - - - - - +---+ | ___________________________________________ | |/ IP/MPLS Network (PHP)-> \| +---------------+ - - - - - - - - - +---------+ ^ \______________|___________________|________/ PW emulation | _________________ | |/ MPLS-TP Network \| +-------------------+ ^ \_________________/ MPLS VPN Equipment: +++++ +++++ + 1 +----+ - - - - - - - - - - - - - - - - - - - - +----+ 8 + +++++ | (PHP)-> | +++++ CE +++++ +++++ +++++ +++++ +++++ CE + 2 +...+ 3 +---+ +- - - - - -+ +-----+ 7 + +++++ +++++ + + + + +++++ LER LSR +LSR+ +++++ +LSR+ LER PE + 4 +...+ 5 +...+ 6 + PE +++++ +++++ +++++ LER LSR LER IP/MPLS encapsulation over MPLS-TP - Network view Figure 8 The equipment 4 and 6 in the above figure act as dual function: o LSR of client IP/MPLS network Martinotti, et al. Expires May 21, 2009 [Page 13] Internet-Draft draft-martinotti-mpst-tp-interworking-00 November 2008 o LER of server MPLS-TP subnetwork As equipment 8 of client IP/MPLS network requires PHP, equipment 6 which act as penultimate hop is required to drop LSP label of client IP/MPLS tunnel (indicated in direction from center to right on equipment number 6). The following figure illustrates the stacking relationship among the technology layers and OAM relationship among the networks: IP/MPLS requires PHP from MPLS-TP Layers: |--------+----------------------CLI----------------+--------| |--SRV--| |---------------------PW------(PHP)->---| |--SRV--| |------+-------+------LSP-----| |--ETH--| |-ETH-| |-ETH-| |-----LSP-----| |--ETY--| |-ETY-| |-ETY-| |-ETH-| |-ETH-| |-ETY-| |-ETY-| OAM: (5) >----O-------------------------------------------O----< CLI (4) >-----------------------------------------< CLI (3) >-------------O---------------?-------< PW (2) >-----------< LSP (1) >--< > - < >---< > - < > - < >-----< >--< PHY Equipment: +++++ +++++ +++++ +++++ +++++ +++++ +++++ +++++ + 1 +--+ 2 +...+ 3 +---+ 4 +...+ 5 +...+ 6 +-----+ 7 +--+ 8 + +++++ +++++ +++++ +++++ +++++ +++++ +++++ +++++ CE LER LSR LER LSR LER LER CE IP/MPLS encapsulation over MPLS-TP - Layers and OAM view Figure 9 A not comprehensive set of OAM is shown in the previous figure, the same generic assumptions as in Section 7.1.1 are considered. A brief description of the different levels is provided: (5) End-to-End Client level OAM on Client network (4) Edge-to-Edge Client level OAM on IP/MPLS network Martinotti, et al. Expires May 21, 2009 [Page 14] Internet-Draft draft-martinotti-mpst-tp-interworking-00 November 2008 (3) Edge-to-Edge MPLS OAM on IP/MPLS network (at PW level) (2) Edge-to-Edge MPLS OAM on MPLS-TP network (at LSP level) (1) Physical level OAM (MAY be of several kind) Open Issues: o As in the IP/MPLS network the LSP, which is tunneled over MPLS-TP network, is terminated on an equipment requiring PHP (Equipment n. 8), IP/MPLS OAM cannot be used at LSP level, so monitoring can be performed at PW level. Interworking between MPLS-TP OAM and IP/ MPLS on node 6 MAY be performed, but its deteils are out of scope of this document. Open Points: o Inteworking between LSP OAM (2) and PW OAM (3) is still to be cleared/defined 7.2. Network Partitioning In the rest of this Section the following roles applies: o Customer network is carried partly over IP/MPLS subnetwork (e.g. via PW encapsulation) and partly over MPLS-TP subnetwork. For the purposes of this Section, MPLS-TP subnetwork is deployed between a CE and an IP/MPLS subnetwork. Other kind of deployment are possible (not shown in this document), for instance: o More than two subnetworks are deployed between the CEs o MPLS-TP can be deployed between two subnetworks 7.2.1. Border Equipment Main features to be taken into account: o MultiSegment Pseudowire o LSP Stitching o Network Interworking o End-to-End OAM support Martinotti, et al. Expires May 21, 2009 [Page 15] Internet-Draft draft-martinotti-mpst-tp-interworking-00 November 2008 o Interaction at Data Plane o Interaction at Management Plane o Possible interaction at Control Plane o Non need of PHP handling of client MPLS Layer 7.2.1.1. Multisegment Pseudowire The following figure illustrates the functional interworking among the networks: Networks: Customer Network +---+ - - - - - - - - - - - - - - - - - +---+ | _______________ _______________ | |/ IP/MPLS Net. \ / MPLS-TP Net. \| +-----------------+-----------------+ ^ \_______________/ \_______________/ PW emulation PWs: |-------------MS-PW-------------| |---------------|---------------| ^ ^ PW segments Equipment: +++++ +++++ + 1 +----+- - - - - - - - - - - - - - - -+----+ 7 + +++++ | | +++++ CE +++++ +++++ +++++ +++++ +++++ CE + 2 +...+ 3 +---+ 4 +...+ 5 +...+ 6 + +++++ +++++ +++++ +++++ +++++ LER LSR LER LSR LER T-PE S-PE T-PE Border Equipment - Multisegment Pseudowire - Networks and PWs view Figure 10 The following figure illustrates the stacking relationship among the technology layers and OAM relationship among the networks: Martinotti, et al. Expires May 21, 2009 [Page 16] Internet-Draft draft-martinotti-mpst-tp-interworking-00 November 2008 Layers: |--------+--------------CLI--------------+--------| |--SRV--| |---------PW---+--------------| |--SRV--| |-----LSP-----| |-----LSP-----| |-ETH-| |-ETH-| |-ETH-| |-ETH-| |-ETY-| |-ETY-| |-ETY-| |-ETY-| OAM: (5) >----O---------------------------------O----< CLI (4) >-------------------------------< CLI (3) >-------------O-------------< MS-PW (2) >-----------< >-----------< LSP (1) >--< > - < >---< > - < > - < >--< PHY Equipment: +++++ +++++ +++++ +++++ +++++ +++++ +++++ + 1 +--+ 2 +...+ 3 +---+ 4 +...+ 5 +...+ 6 +--+ 7 + +++++ +++++ +++++ +++++ +++++ +++++ +++++ CE LER LSR LER LSR LER CE Border Equipment - Multisegment Pseudowire - Layers and OAM view Figure 11 A not comprehensive set of OAM is shown in the previous figure, the same generic assumptions as in Section 7.1.1 are considered. A brief description of the different levels is provided: (5) End-to-End Client level OAM on Client network (4) Edge-to-Edge Client level OAM on partitioned network (3) Edge-to-Edge MPLS OAM on partitioned network (at PW level) (2) Edge-to-Edge MPLS OAM on partitioned network (at LSP level) (1) Physical level OAM (MAY be of several kind) Open Issues: o None up to now Open Points: o Inteworking between LSP OAM (2) and MS-PW OAM (3) is still to be cleared/defined Martinotti, et al. Expires May 21, 2009 [Page 17] Internet-Draft draft-martinotti-mpst-tp-interworking-00 November 2008 o Edge-to-Edge Client level OAM (4) must be configuerd on different subnetworks 7.2.1.2. LSP stitching The following figure illustrates the functional interworking among the networks: Networks: Customer Network +---+ - - - - - - - - - - - - - - - - - +---+ | _______________ _______________ | |/ IP/MPLS Net. \ / MPLS-TP Net. \| +-----------------+-----------------+ ^ \_______________/ \_______________/ PW emulation PWs: |-------------SS-PW-------------| Equipment: +++++ +++++ + 1 +----+- - - - - - - - - - - - - - - -+----+ 9 + +++++ | | +++++ CE +++++ +++++ +++++ +++++ +++++ CE + 2 +...+ 3 +---+ 4 +...+ 5 +...+ 6 + +++++ +++++ +++++ +++++ +++++ LER LSR LER LSR LER PE PE Border Equipment - LSP stitching - Networks and PWs view Figure 12 The following figure illustrates the stacking relationship among the technology layers and OAM relationship among the networks: Martinotti, et al. Expires May 21, 2009 [Page 18] Internet-Draft draft-martinotti-mpst-tp-interworking-00 November 2008 Layers: |--------+--------------CLI--------------+--------| |--SRV--| |--------------PW-------------| |--SRV--| |-------------<->-LSP---------| |-ETH-| |-ETH-| |-ETH-| |-ETH-| |-ETY-| |-ETY-| |-ETY-| |-ETY-| OAM: (6) >----O---------------------------------O----< CLI (5) >-------------------------------< CLI (4) >---------------------------< PW (3) >-------------O-------------< LSP (2) >-----------< >-----------< TCM (1) >--< > - < >---< > - < > - < >--< PHY Equipment: +++++ +++++ +++++ +++++ +++++ +++++ +++++ + 1 +--+ 2 +...+ 3 +---+ 4 +...+ 5 +...+ 6 +--+ 7 + +++++ +++++ +++++ +++++ +++++ +++++ +++++ CE LER LSR LER LSR LER CE Border Equipment - LSP stitching - Layers and OAM view Figure 13 Note: in this case a SS-PW extends over the subnetworks as the stitched LSP does. TCM can be used to monitor the LSP segments. A not comprehensive set of OAM is shown in the previous figure, the same generic assumptions as in Section 7.1.1 are considered. A brief description of the different levels is provided: (6) End-to-End Client level OAM on Client network (5) Edge-to-Edge Client level OAM on partitioned network (4) Edge-to-Edge MPLS OAM on partitioned network (at PW level) (3) Edge-to-Edge MPLS OAM on partitioned network (at LSP level) (2) Edge-to-Edge MPLS OAM on partitioned network (at TCM level) (1) Physical level OAM (MAY be of several kind) Open Issues: Martinotti, et al. Expires May 21, 2009 [Page 19] Internet-Draft draft-martinotti-mpst-tp-interworking-00 November 2008 o None up to now Open Points: o Inteworking between TCM OAM (2) and LSP OAM (3) is still to be cleared/defined 7.2.2. Border Link Main features to be taken into account: o MultiSegment Pseudowire o LSP Stitching o Interaction at Data Plane o Interaction at Management Plane o Possible interaction at Control Plane o Possible PHP handling of client MPLS Layer 7.2.2.1. Multisegment Pseudowire The following figure illustrates the functional interworking among the networks: Martinotti, et al. Expires May 21, 2009 [Page 20] Internet-Draft draft-martinotti-mpst-tp-interworking-00 November 2008 Networks: Customer Network +---+ - - - - - - - - - - - - - - - - - -+---+ | ___________ ______________ | |/IP/MPLS N. \ / MPLS-TP N. \| +-------------+-----+----------------+ ^ \___________/ \______________/ PW emulation PWs: |------------MS-PW--------------| |-----------|-----|-------------| ^ ^ ^ PW segments Equipment: +++++ +++++ + 1 +----+- - - - - - - - - - - - - - - -+----+ 6 + +++++ | | +++++ CE +++++ +++++ +++++ +++++ CE + 2 +.....+ 3 +-----+ 4 +.......+ 5 + +++++ +++++ +++++ +++++ LER LER LER LER T-PE S-PE S-PE T-PE Border Link - Multisegment Pseudowire - Networks view Figure 14 The following figure illustrates the stacking relationship among the technology layers and OAM relationship among the networks: Martinotti, et al. Expires May 21, 2009 [Page 21] Internet-Draft draft-martinotti-mpst-tp-interworking-00 November 2008 Layers: |--------+-------------CLI---------------+--------| |--SRV--| |--------+----PW---+----------| |--SRV--| |--LSP--| |--LSP--| |---LSP---| |- ETH -| |--ETH--| |- -ETH- -| |- ETY -| |--ETY--| |- -ETY- -| OAM: (5) >----O---------------------------------O----< CLI (4) >-------------------------------< CLI (3) >-------O---------O---------< MS-PW (2) >-----< >-----< >-------< LSP (1) >--< > - - < >-----< > - - - < >--< PHY Equipment: +++++ +++++ +++++ +++++ +++++ +++++ + 1 +--+ 2 +.....+ 3 +-----+ 4 +.......+ 5 +--+ 6 + +++++ +++++ +++++ +++++ +++++ +++++ CE LER LER LER LER CE Border Link - Multisegment Pseudowire - Layers and OAM view Figure 15 A not comprehensive set of OAM is shown in the previous figure, the same generic assumptions as in Section 7.1.1 are considered. A brief description of the different levels is provided: (5) End-to-End Client level OAM on Client network (4) Edge-to-Edge Client level OAM on partitioned network (3) Edge-to-Edge MPLS OAM on partitioned network (at PW level) (2) Edge-to-Edge MPLS OAM on partitioned network (at LSP level) (1) Physical level OAM (MAY be of several kind) Open Issues: o None up to now Open Points: o Inteworking between LSP OAM (2) and MS-PW OAM (3) is still to be cleared/defined Martinotti, et al. Expires May 21, 2009 [Page 22] Internet-Draft draft-martinotti-mpst-tp-interworking-00 November 2008 7.2.2.2. LSP stitching The following figure illustrates the functional interworking among the networks: Networks: Customer Network +---+ - - - - - - - - - - - - - - - - - -+---+ | ___________ ______________ | |/IP/MPLS N. \ / MPLS-TP N. \| +-------------+-----+----------------+ ^ \___________/ \______________/ PW emulation PWs: |------------SS-PW--------------| Equipment: +++++ +++++ + 1 +----+- - - - - - - - - - - - - - - -+----+ 6 + +++++ | | +++++ CE +++++ +++++ +++++ +++++ CE + 2 +.....+ 3 +-----+ 4 +.......+ 5 + +++++ +++++ +++++ +++++ LER LER LER LER PE PE Border Link - LSP stitching - Networks view Figure 16 The following figure illustrates the stacking relationship among the technology layers and OAM relationship among the networks: Martinotti, et al. Expires May 21, 2009 [Page 23] Internet-Draft draft-martinotti-mpst-tp-interworking-00 November 2008 Layers: |--------+-------------CLI---------------+--------| |--SRV--| |-------------PW--------------| |--SRV--| |-------<->--LSP--<->---------| |- ETH -| |--ETH--| |- -ETH- -| |- ETY -| |--ETY--| |- -ETY- -| OAM: (6) >----O---------------------------------O----< CLI (5) >-------------------------------< CLI (4) >---------------------------< SS-PW (3) >-------O---------O---------< LSP (2) >-----< >-----< >-------< TCM (1) >--< > - - < >-----< > - - - < >--< PHY Equipment: +++++ +++++ +++++ +++++ +++++ +++++ + 1 +--+ 2 +.....+ 3 +-----+ 4 +.......+ 5 +--+ 6 + +++++ +++++ +++++ +++++ +++++ +++++ CE LER LER LER LER CE Border Link - LSP stitching - Layers and OAM view Figure 17 Note: in this case a SS-PW extends over the subnetworks as the stitched LSP does. TCM can be used to monitor the LSP segments. A not comprehensive set of OAM is shown in the previous figure, the same generic assumptions as in Section 7.1.1 are considered. A brief description of the different levels is provided: (6) End-to-End Client level OAM on Client network (5) Edge-to-Edge Client level OAM on partitioned network (4) Edge-to-Edge MPLS OAM on partitioned network (at PW level) (3) Edge-to-Edge MPLS OAM on partitioned network (at LSP level) (2) Edge-to-Edge MPLS OAM on partitioned network (at TCM level) (1) Physical level OAM (MAY be of several kind) Open Issues: o None up to now Open Points: Martinotti, et al. Expires May 21, 2009 [Page 24] Internet-Draft draft-martinotti-mpst-tp-interworking-00 November 2008 o Inteworking between TCM OAM (2) and LSP OAM (3) is still to be cleared/defined 8. Conclusions This document has illustrated some interworking scenarios between MPLS-TP and IP/MPLS. Where open points and open issues are still present, the reader is invited to contribute to their resolution. 9. Acknowledgements The authors gratefully acknowledge the input of Attila Takacs. 10. IANA Considerations This memo includes no request to IANA. 11. Security Considerations All drafts are required to have a security considerations section. See bla bla bla... 12. References 12.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. 12.2. Informative References [RFC3031] Rosen, E., Viswanathan, A., and R. Callon, "Multiprotocol Label Switching Architecture", RFC 3031, January 2001. [draftjenkins] Niven-Jenkins, B., Brungard, D., and M. Betts, "MPLS-TP Requirements", ID draft-jenkins-mpls-mpls-tp-requirements-00, July 2008. [draftblb] Bocci, M., Lasserre, M., and S. Bryant, "A Framework for MPLS in Transport Networks", ID draft-blb-mpls-tp-framework-00, July 2008. Martinotti, et al. Expires May 21, 2009 [Page 25] Internet-Draft draft-martinotti-mpst-tp-interworking-00 November 2008 [draftvigoureux] Vigoureux, M., "Requirements for OAM in MPLS Transport Networks", ID draft-vigoureux-mpls-tp-oam-requirements-00, June 2008. Appendix A. Additional Stuff This becomes an Appendix. Authors' Addresses Riccardo Martinotti Ericsson Via A. Negrone 1/A Genova - Sestri Ponente 16153 Italy Email: riccardo.martinotti@ericsson.com Diego Caviglia Ericsson Via A. Negrone 1/A Genova - Sestri Ponente 16153 Italy Email: diego.caviglia@ericsson.com Nurit Sprecher Nokia Siemens Networks 3 Hanagar St. Neve Ne'eman B Hod Hasharon 45241 Israel Email: nurit.sprecher@nsn.com Martinotti, et al. Expires May 21, 2009 [Page 26] Internet-Draft draft-martinotti-mpst-tp-interworking-00 November 2008 Full Copyright Statement Copyright (C) The IETF Trust (2008). 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The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights that may cover technology that may be required to implement this standard. Please address the information to the IETF at ietf-ipr@ietf.org. Martinotti, et al. Expires May 21, 2009 [Page 27]