Monday, March 08, 2010

L2VPN/VPLS-Martini and Kompella

Both Martini-draft and Kompella-draft addressed setting up of a Pseudowire emulation over MPLS in order to offer L2VPN services. These drafts were initial efforts to standardise L2VPN services.

Martini draft was named after a former Cisco employee Luca Martini. Martini draft uses LDP as signalling to setup L2VPN over MPLS backbone. The tradeoff of this draft was auto-discovery.
Kompella draft on the other hand uses BGP for both signalling and auto-discovery to establish fully-meshed pseudo wires (multipoint). Kompella-draft is named after author Keerti Kompella (Juniper Employee).

draft-martini and draft-kompella terms are used as labels for the two different L2VPN services methodologies (LDP Vs BGP for signaling). The actual drafts do not exist in IETF.
In dealing with multipoint-fully meshed topologies in edge routers, draft-martini suffered auto-discovery, to overcome aut0-discovery, it suffered configuration overhead. draft-Kompella claimed to be better scalable because of suto-discovery but with complex signalling whereas draft-martini leverages simplicity.

Martini draft was standardized under RFC 4096 . however it has since been superseded by the Pseudowire Emulation Edge to Edge (PWE3) Working Group specifications described in RFC 4447 and related documents. On the other hand draft-kompella is obsolete and was not standardized.

RFC 4664 - Framework for Layer 2 Virtual Private Networks (L2VPN), it describes the framework for L2VPNs (VPWS, VPLS and IPLS). This framework is intended to aid in standardizing protocols and mechanisms to support interoperable L2VPNs. Requirements for L2VPNs can be found in RFC 4665 – Service Requirements for Layer 2 Provider-Provisioned Virtual Private Networks.

All this was consolidated, and the L2VPN Working Group produced two separate documents, RFC 4761 and RFC 4762, both offered VPLS but using different signaling protocols:
Kireeti Kompella and Yakov Rekhter published “Virtual Private LAN Service (VPLS) Using BGP for Auto-discovery and Signaling” RFC 4761 in January 2007.

Marc Lasserre and Vach Kompella published “Virtual Private LAN Service (VPLS) Using Label Distribution Protocol (LDP) Signaling” RFC 4762 in January 2007.

L2VPN services for many vendors uses RFC 4762 -Martini ( with LDP) as a standard for example Alcatel 7450’s uses RFC 4762 as the standard

Taken From ciscotips.wordpress.com