Provisioning, Auto-Discovery, and Signaling in Layer 2 Virtual Private Networks (L2VPNs)
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From: The IESG <email@example.com> To: IETF-Announce <firstname.lastname@example.org> Cc: Internet Architecture Board <email@example.com>, RFC Editor <firstname.lastname@example.org>, l2vpn mailing list <email@example.com>, l2vpn chair <firstname.lastname@example.org> Subject: Protocol Action: 'Provisioning, Autodiscovery, and Signaling in L2VPNs' to Proposed Standard The IESG has approved the following document: - 'Provisioning, Autodiscovery, and Signaling in L2VPNs ' <draft-ietf-l2vpn-signaling-08.txt> as a Proposed Standard This document is the product of the Layer 2 Virtual Private Networks Working Group. The IESG contact persons are Mark Townsley and Jari Arkko. A URL of this Internet-Draft is: http://www.ietf.org/internet-drafts/draft-ietf-l2vpn-signaling-08.txt
Technical Summary There are a number of different kinds of "Provider Provisioned Layer 2 VPNs" (L2VPNs). The different kinds of L2VPN may have different "provisioning models", i.e., different models for what information needs to be configured in what entities. Once configured, the provisioning information is distributed by a "discovery process". When the discovery process is complete, a signaling protocol is automatically invoked. The signaling protocol sets up the mesh of Pseudowires (PWs) that form the (virtual) backbone of the L2VPN. Any PW signaling protocol needs to have a method which allows each PW endpoint to identify the other; thus a PW signaling protocol will have the notion of an endpoint identifier. The semantics of the endpoint identifiers which the signaling protocol uses for a particular type of L2VPN are determined by the provisioning model. This document specifies a number of L2VPN provisioning models, and further specifies the semantic structure of the endpoint identifiers required by each provisioning model. It discusses the way in which the endpoint identifiers are distributed by the discovery process, especially when the discovery process is based upon the Border Gateway Protocol (BGP). It then specifies how the endpoint identifiers are carried in the two signaling protocols that are used to set up PWs, the Label Distribution Protocol (LDP) and the Layer 2 Tunneling Protocol (L2TPv3). Working Group Summary After WG Last Call, Luca Martini had raised an issue with respect to whether or not there needed to be coordination of AII Types between the l2vpn-signaling draft and the emergent MS-PW work. Luca proposed a solution to this dilemma on the L2VPN WG list: http://www.ietf.org/mail-archive/web/l2vpn/current/msg01121.html A discussion ensued between Bruce, Luca, Chris Metz, Florin, Mustapha, Vach & Shane to resolve it. In summary, we have all agreed that l2vpn-signaling is its own application and its use of Type-1 AII's is sufficient for it. In fact, procedures developed in l2vpn-signaling already account for PW routing/stitching & signaling as it relates to D-VPLS, (with Type-1 AII's), but do not give one the granularity of routing that MS-PW is aiming for. Another key difference is that l2vpn-signaling is focused on auto-discovery mechanisms for groups of PW's (e.g.: L2VPN's), whereas MS-PW is focused on both routing and signaling invidual PW's (not groups of PW's). In fact, it's not clear that MS-PW will initially be designed to support routing+signaling of groups of PW's, (which is another thing that distinguishes it from l2vpn-signaling). Protocol Quality The protocol is being implemented by at least two vendors. RFC Editor Note: Please add a normative reference for RFC 2119 and a citation to it at the end of section 1. Please replace: 188.8.131.52. BGP-based auto-discovery A framework for BGP-based auto-discovery for a generic L2VPN service is described in [I-D.ietf-l3vpn-bgpvpn-auto], section 3.2. In this section we specify how BGP-based auto-discovery can be used to build VPWS instances. With: 184.108.40.206. BGP-based auto-discovery In this section we specify how BGP can be used to discover the information necessary to build VPWS instances. And replace: "A framework for BGP-based auto-discovery for a generic L2VPN service is described in [I-D.ietf-l3vpn-bgpvpn-auto], section 3.2. In this section we specify how BGP-based auto-discovery can be used to build VPLS instances." With: "In this section we specify how BGP can be used to discover the information necessary to build a VPLS instance." Also, please remove the bibliographic reference to [I-D.ietf-l3vpn-bgpvpn-auto] in its entirety.