Related Documentation
Introduction to Inter-AS VPLS with MAC Processing at the ASBR
Virtual Private LAN Service (VPLS) is a key enabler for delivering multipoint Ethernet services. Major service providers have implemented IP and MPLS backbones and offer VPLS transparent LAN services to large enterprises. VPLS appeals to enterprises since it allows them to extend their reach beyond their local areas with the same layer 2 Ethernet connectivity paradigm.
An inter-provider VPN offers the ability to extend the reach of VPNs across multiple providers. When two companies merge and have offices spread across large geographic and administrative domains, inter-provider agreements and support are required to provide full VPN connectivity and a single complete bill for the network services. A standards-based approach is one mechanism to provide this support.
Inter-AS VPLS with MAC processing between BGP-signaled VPLS and LDP-signaled VPLS is described in RFC 4761 as multi-AS VPLS option E or method E. Inter-AS VPLS option E proposes a combination of the control and scaling capabilities offered by option A and the automation capabilities provided by option B.
This feature is useful when a single VPLS instance is spread across a group of provider edge (PE) routers. A set of PE routers using BGP signaling might not be aware of another set of PE routers using LDP signaling. The PE routers using LDP signaling might not be aware of the set of PE routers using BGP signaling and there might be multiple sets of such PE routers.
