Inter-AS Option B is supported for Rosen MVPN PIM SSM using BGP MDT SAFI, PIM RPF Vector and BGP Connector attribute. The Figure 1 depict set-up of a default MDT:
Figure 1. Inter-AS Option B Default MDT Setup
SR OS inter-AS Option B is designed to be standard compliant based on the following RFCs:
RFC 5384 - The Protocol Independent Multicast (PIM) Join Attribute Format
RFC 5496 - The Reverse Path Forwarding (RPF) Vector TLV
RFC 6513 - Multicast in MPLS/BGP IP VPNs
The SR OS implementation was designed also to interoperate with older routers Inter-AS implementations that do not comply with the RFC 5384 and RFC 5496.