Posts Tagged ‘p2mp lsp’
The purpose of this blog post is to give you a brief overview of M-LSPs, the motivation behind this technology and demonstrate some practical examples. We start with Multicast VPNs and then give an overview of the M-LSP implementations based on M-LDP and RSVP-TE extensions. The practical example is based on the recently added RSVP-TE signaling for establishing P2MP LSPs. All demostrations coud be replicated using the widely available Dynamips hardware emulator. The reader is assumed to have solid understanding of MPLS technologies, including LDP, RSVP-TE, MPLS/BGP VPNs and Multicast VPNs.
Multicast Domains Model
For years, the most popular solution for transporting multicast VPN traffic was using native IP multicast in SP core coupled with dynamic multipoint IP tunneling to isolate customer traffic. Every VPN would be allocated a separate MDT (Multicast Distribution Tree) or domain mapped to a core multicast group. Regular IP multicast routing is then used for forwarding, using PIM signaling in core. Notice, that the core network has to be multicast enabled in Multicast Domains model. This model is well mature by today and allows for effective and stable deployments even in Inter-AS scenarios. However, for the long time the question with MPVNs was – could we replace IP tunneling with MPLS label encapsulation? And the main motivation for moving to MPLS label switching would be leveraging MPLS traffic-engineering and protection features.