1. Multicast in Virtual Router-based IP VPNs
<draft-zhang-l3vpn-vr-mcast-01.txt>
Beijing Jiaotong University
Huawei Technologies Co., Ltd.

2. Content Overview of background VR-VPN deployment scenarios
Auto-Discovery for multicast in VR-VPN
Procedures for multicast in VR-VPN
Scalability and Security

3. Overview of background
Solutions for provider provisioned L3VPN
---BGP/MPLS IP VPNs (rfc2547bis)
---IP VPNs using Virtual Routers (VR-VPN)
---CE-based VPNs using IPsec
Requirements for multicast in L3VPN
<draft-ietf-l3vpn-ppvpn-mcast-reqts-01>
Solutions for multicast in L3VPN
---Multicast in BGP/MPLS IP VPN
<draft-ietf-l3vpn-2547bis-mcast-00>
---Multicast in VR-VPN (none)
---Multicast in CE-based VPN using IPsec (none)

4. VR-VPN deployment scenarios
This solution fits for all above VR deployment scenarios.
--- VR to VR connectivity over layer 2;
--- VR to VR connectivity tunneled over an IP or MPLS network;
--- Aggregating multiple VRs over a backbone VR.

5. Auto-discovery for multicast VR-VPN
The mechanism to distribute membership, topology, and tunnel information among VRs for multicast in VR-VPN is the same as for unicast in VR-VPN.
--- explicit configuration
--- directory server approach
--- extended BGP
--- protocols or other approaches

6. Procedures -- Encapsulation
Encapsulation methods
--- Encapsulation in GRE (suggested)
--- Encapsulation in IP
--- Encapsulation in MPLS
All VRs in a VR-VPN must agree on the method of encapsulation. This can be achieved either by configuration or by means of discovery protocols.

7. Procedures -- Multicast source routing table
--- Store in VR to decide whether there exists multicast requirements from local VPN sites

8. (C-Source, C-Group) or (*, C-Group)
Procedures --Routing in the VPN sites
Routing in the VPN sites
(C-Source, C-Group) or (*, C-Group)
proxy Source/RP

9. Procedures – Routing in the SP network
(Source_VR, P-Group)
Prune (VR_A2, P-Group)
以VR_A1,VR_A2为源分别建立两棵源树(红色,蓝色),当VRA3中没有对S3和S4的需求时向VR_A2发送剪枝消息 prune (VR_A2, P-Group).

10. Scalability and Security
Scalability Considerations
--- The number of trees in SP core will not exceed the number of VRs
--- The group address in SP core (Source_VR, P-Group)
--- Reduce payload in SP core by aggregating (C-Source, C-Group)
into (Source_VR, P-Group)
Security Considerations
--- Good isolation between different VPNs

11. Thanks for your attention and suggestion !
<draft-zhang-l3vpn-vr-mcast-01.txt>
Contact info:
Spencer Dawkins
Hong-Ke Zhang