Multicast in BGP/MPLS VPNs draft-ietf-l3vpn-2547bis-mcast-00.txt

1. Multicast in BGP/MPLS VPNsdraft-ietf-l3vpn-2547bis-mcast-00.txt Eric Rosen (erosen@cisco.com) Rahul Aggarwal (rahul@juniper.net)

2. Other Authors/Contributors • Co-Authors • Sarveshwar Bandi, Yiqun Cai, Thomas Morin, Yakov Rekhter, IJsbrands Wijnands, Seisho Yasukawa • Contributors/Acknowledgements • Arjen Boers, Toerless Eckert, Adrian Farrel, Luyuan Fang, Dino Farinacci, Lenny Guiliano, Shankar Karuna, Anil Lohiya, Tom Pusateri, Ted Qian, Robert Raszuk, Tony Speakman, Dan Tappan

3. Resolve Open Issues.. • Reduce options if possible • Specify required and optional procedures • Intention is to outline the issues and initiate a discussion. • The discussion will continue on the mailing list and between the authors. • Let us look at the following • MVPN Routing Information Exchange • Service Provider Tunneling Technologies • Protocol for switching to S-PMSI • Co-locating C-RPs on a PE

4. MVPN Routing Information Exchange • Scalability of the entire system • Does the mechanism require frequent periodic refresh ? • Number of protocol sessions required to exchange MVPN routing information • Consider rate of churn of C-Joins/Prunes • Does the protocol support mechanisms that prevent PEs from receiving unwanted routing information ? • Can the mechanism be used with UI-PMSI, MI-PMSI, S-PMSI ? • Inter-provider manageability and security – does the mechanism require direct PE-PE communication ? • How well does the mechanism fit with the operational model of 2547 unicast ?

5. MVPN Routing Information Exchange…(Not an Exhaustive List) Periodic Refresh Sessions Per PE UI-PMSI MI-PMSI S-PMSI BGP PIM Unicast PIM Multicast

6. MVPN Routing Information Exchange…Other Considerations • If BGP, is used route filtering is recommended to prevent PEs from receiving unwanted routing information • Filtering has a processing cost associated with it • If BGP is used it is possible to handle growth of multicast control traffic by • Using separate RRs for MVPN control traffic • Partitioning RRs between MVPNs

7. MVPN Routing Information Exchange… • Consider the most pragmatic option that meets most of the requirements • Mandate the support of BGP ? • BGP Encoding mechanisms will be published shortly • Eliminate PIM unicast ?

8. SP Tunneling Technologies • Provide options as long as the options have significantly different operational/performance characteristics • Current options: • Ingress Replication (MPLS or IP/GRE) • P2MP MPLS TE LSPs – RSVP-TE • P2MP/MP2MP MPLS Receiver Driven LSPs - LDP • PIM-SSM with GRE • PIM-SM with GRE • PIM-Bidir with GRE

9. SP Tunneling Technologies… • Do we need to deprecate PIM-SM with GRE ? • Discovery is done using BGP • Shared trees can be built using PIM-SSM model

10. Protocol for Switching to S-PMSI • Currently two protocols are specified • UDP • BGP • Settle on one or show clearly that there is a different applicability for each • Scalability • Periodic refresh • Number of sessions per PE • Rate of churn of C-Join/C-Prunes • Filtering ability • How well does the protocol fit with rest of the MVPN architecture ?

11. Co-locating C-RPs on a PE • Mandatory or optional or should it be in the spec ? • Currently two options are specified • Anycast RP based on C-(*, G) advertisments • Anycast RP based on propagating active sources • If co-locating C-RPs on a PE is kept in the spec we must settle on one of these • Which one introduces additional mechanisms ? • Any other implications ?

12. Conclusion • Goal is to address these issues by the next IETF and produce a 01 version.