1. March 2010IETF 77, MPLS WG1 Carrying PIM-SM in ASM mode Trees over P2MP mLDP LSPs draft-rekhter-pim-sm-over-mldp-01.txt Y. Rekhter, Juniper Networks R. Aggarwal, Juniper Networks N. Leymann, Deutsche Telekom

2. March 2010IETF 77, MPLS WG2 Problem Statement For some applications it may be desirable to map IP multicast trees to P2MP LSPs, when such trees pass through a MPLS domain When the P2MP LSPs are signaled using P2MP LDP, draft-wijnands-mpls-mldp-in-band-signaling describes how to map PIM-SM in SSM mode trees to P2MP LDP LSPs draft-wijnands-mpls-mldp-in-band-signaling does not describe how to map PIM-SM in ASM mode trees to P2MP LDP LSPs Draft-rekhter-pim-sm-over P2MP LDP describes how to map PIM-SM in ASM mode trees to P2MP LDP LSPs

3. March 2010IETF 77, MPLS WG3 Solution (1) Use a combination of BGP and P2MP LDP to map PIM-SM in ASM mode trees to P2MP LSP Use BGP Source Active (SA) A-D routes described in draft-ietf-l3vpn-2547bis-mcast-bgp Two options –Option 1 – does not transit IP multicast shared trees over the MPLS network –Option2 – enables transit of IP multicast shared trees over the MPLS network

4. March 2010IETF 77, MPLS WG4 Solution (2) Each IP multicast source tree is mapped one-to-one to a P2MP LSP in the MPLS network –Just like draft-wijnands-mpls-mldp-in-band- signaling –This type of service works well if the number of LSPs that are created is under control of the MPLS network operator, or if the number of LSPs for a particular service are known to be limited in number.

5. March 2010IETF 77, MPLS WG5 Comparison with BGP MVPN BGP MVPN procedures as described in draft-ietf-l3vpn- 2547bis-mcast can be used to map IP multicast trees to P2MP LSPs –Both for PIM-SM in SSM mode and PIM-SM in ASM mode BGP MVPN procedures also support the ability to aggregate multiple IP multicast trees to one P2MP LSP in the MPLS network. The procedures of draft-rekhter-pim-sm-over-mldp-01.txt can be viewed as an optimization, compared to the reuse of the BGP MVPN procedures –Maybe beneficial in some deployment scenarios

6. March 2010IETF 77, MPLS WG6 Option 1 IP multicast shared trees do not transit over the MPLS network BGP Source Active routes are used by a RP to advertise active multicast sources A LSR that has downstream (*, G) IP multicast state creates (S, G) IP multicast state based on the presence of a BGP SA A-D route for (S, G) –The LSR maps the (S, G) state to a P2MP LDP LSP Traffic flows only on a source tree over the MPLS network –There is no shared tree to source tree switch over the MPLS network

7. March 2010IETF 77, MPLS WG7 Option 2 IP multicast shared trees transit over the MPLS network A LSR maps downstream (*, G) IP Multicast state into P2MP LDP using new transit shared tree TLVs which embed the RP address instead of the source address BGP Source Active routes are used to force all LSRs to switch from shared tree to source tree –Once a single LSR joins the source tree –Prunes sources that are reachable over the MPLS network off the shared tree BGP SA A-D routes are originated by a LSR that: –receives a P2MP LDP LSP for the given source and for a group in the ASM range –is on the path to reach the source via an IP multicast interface

8. March 2010IETF 77, MPLS WG8 Comments?