The MPLS WG Archive[Date Prev][Date Next][Thread Prev][Thread Next] [Date Index][Thread Index][Author Index][Subject Index] [mpls] [Fwd: New Liaison Statement,"Clarification on the intended scope of T-MPLS"]
All, we have received the included liaison from ITU-T SG 15. Note that we've two slightly mixed discussion, one on MPLS and another on pseudo wires. Try to direct comments to the appropriate working group list. we plan to give a formal response on May 17th, comments, both on the content of this liaison and on the T-MPLS documentation, are welcome. Loa and George -------- Original Message -------- Subject: New Liaison Statement, "Clarification on the intended scope of T-MPLS" Date: Thu, 04 May 2006 14:09:26 -0400 From: Greg Jones(ITU-T SG 15) <tsbsg15@itu.int> Reply-To: tsbsg15@itu.int To: George Swallow <swallow@cisco.com>, Loa Andersson <loa@pi.se>, Stewart Bryant <stbryant@cisco.com>, Danny McPherson <danny@arbor.net> CC: Scott Bradner <sob@harvard.edu>, Yoichi Maeda <maeda@ansl.ntt.co.jp>, sjtrowbridge@lucent.com, ghani.abbas@marconi.com, betts01@nortel.com, tsbsg15@itu.int, greg.jones@itu.int, ghani.abbas@marconi.com, betts01@nortel.com Title: Clarification on the intended scope of T-MPLS Submission Date: 2006-05-04 URL of the IETF Web page: https://datatracker.ietf.org/public/liaison_detail.cgi?detail_id=218 From: Greg Jones(ITU-T SG 15) <tsbsg15@itu.int> To: IETF MPLS WG, PWE3 WG(George Swallow <swallow@cisco.com>, Loa Andersson <loa@pi.se>, Stewart Bryant <stbryant@cisco.com>, Danny McPherson <danny@arbor.net>) Cc: Scott Bradner <sob@harvard.edu> Yoichi Maeda <maeda@ansl.ntt.co.jp> sjtrowbridge@lucent.com ghani.abbas@marconi.com betts01@nortel.com Reponse Contact: tsbsg15@itu.int greg.jones@itu.int Technical Contact: ghani.abbas@marconi.com betts01@nortel.com Purpose: For information Body: Thank you for your informal feedback that has been provided on our previous liaison statement on T-MPLS Consented Recommendations, we also understand that you are in the process of developing a formal response. To assist you in providing your formal response we would like to provide some additional clarifications on the intended application of T-MPLS. Our intention in developing the suite of T-MPLS Recommendations was to define a packet based transport network technology. The design objectives of T-MPLS were: a) Follow the principles of the transport network used in other ITU-T defined transport technologies (e.g SDH, ATM, OTN). b) To use the PDU and data plane processes defined by the IETF for MPLS. T-MPLS is not intended to duplicate the functionality already provided by IP/MPLS. The only client fully described in the current version of G.8110.1 is point to point Ethernet Virtual Connection (EVC). It was agreed to revise the scope of the Recommendation and provide an appendix II (attached) to reflect this. Some other key points identified were: • The current version of G.8110.1 only defines the bearer plane and only point to point trails are currently supported. It should be noted that version 2 of G.8110.1 will add point to multipoint trails. • Any interworking with client signals (e.g. MPLS, Ethernet) will be client server i.e. any client OAM or control protocols will be tunneled transparently across the T-MPLS layer network. • Interworking between a client control plane and a (yet to be defined) T-MPLS control plane will be addressed as a part of the control plane architecture work. • The T-MPLS network provides a single hop link to the client, it is intended to offer a packet switched connection that has similar operational characteristics to a SDH network providing a PDH link connection, e.g. these connections must support the ability to activate performance monitoring and fault management. Any PM data or failures will be reported to the transport operations center. We also note your comments on the usage of the label space terminology. We will work to clarify and if necessary correct this in a future revision. We have also agreed to initiate work on the architecture of a control plane for T-MPLS. We will use the ASON architecture to provide a framework to describe the problem that is to be addressed. This does not imply that we will specify an ASON control plane. Once we have refined our requirements we will communicate them to you for advice on how they may be addressed. If the requirements cannot be met by an existing protocol suite we would like to work with you to develop the appropriate enhancements. We will be continuing our work on T-MPLS in particular the support of other clients (e.g. IP/MPLS) at an interim meeting that is planned to be held 19-23 June in Ottawa Canada. We will also address any comments that you provide in your planned liaison statement. Any urgent changes may be included in an amendment or corrigendum that could be consented in October 2006. IETF experts are welcome to participate at this meeting. Please contact betts01@nortel.com by May 31st 2006 if you should wish to participate. G.8110.1 draft Appendix II Support of IP/MPLS LSR based networks by T-MPLS networks supporting point-to-point EVC services When two IP/MPLS LSRs are connected via e.g. 802.3 interfaces to a T-MPLS network, the T-MPLS network can provide an EVC service between these two LSRs (nodes LSR A and LSR B in Figure II-1) to establish an IP/MPLS link between these LSRs. The IP/MPLS LSRs encapsulate their IP/MPLS packets into Ethernet frames with or without VLAN Tag. These Ethernet frames are then transported via 802.3 interfaces to the T-MPLS network edge (nodes X and Y). At the T-MPLS network edge the Ethernet signal is treated either as an all-to-one EVC service or as one or more EVC and/or bundled EVC services of which the frames are mapped into one or more T-MPLS (PW) trails and then transported through the T-MPLS network. In this network scenario the IP/MPLS routing and control plane adjacency is between LSR A and LSR B. The T-MPLS network elements do not participate in the IP/MPLS routing and control plane. A signalling session that requests PHP is between LSR A and LSR B (T-MPLS nodes X and Y are not involved). Figure II-1/G.8110.1 – IP/MPLS via EVC over T-MPLS network The functional model for this scenario is described in Figure II-2. The atomic functions in the figure are specified in Recommendations G.8021 and G.8121.The IP/MPLS signals are carried through an IP/MPLS link between LSR A and LSR B supported by an ETH trail between LSR A and LSR B. The ETH trail is carried through a serial-compound ETH link supported by an ETY trail interconnecting LSR A with T-MPLS PE X, a T-MPLS (PW) trail interconnecting T-MPLS PE X with T-MPLS PE Y and an ETY trail interconnecting T-MPLS PE Y with LSR B. <<Figure II-2/G.8110.1 – Functional Model for IP/MPLS via EVC over T-MPLS network>> - see attachment Attachment(s): Clarification on the intended scope of T-MPLS (see this WinWord file for the diagrams) (https://datatracker.ietf.org/documents/LIAISON/file311.doc) -- Loa Andersson Principal Networking Architect Acreo AB phone: +46 8 632 77 14 Isafjordsgatan 22 mobile: +46 739 81 21 64 Kista, Sweden email: loa.andersson@acreo.se loa@pi.se _______________________________________________ mpls mailing list mpls@lists.ietf.org https://www1.ietf.org/mailman/listinfo/mpls |
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