1. PE-based IPv6 multicast transition for mesh problem
Yong CERNET

2. Why we need multicast transition?
From CERNET
Existing multicast applications are in IPv4
Native IPv6 CERNET2 is expected to support IPv4 multicast applications
IPv4 multicast traffic is low

3. What’s multicast transition problem
How to setup a multicast tree in IPv6 backbone where edge of tree should be PE? ?

4. Auto-discovery members in mesh framework
Auto-discovery of PEs (N PEs totally)
Mesh framework or 4over6 based on MP-BGP

5. Potential solution Construct multicast tree in IPv6 backbone
Dynamic mapped IPv6 tree (M trees)
Dynamically mapping IPv4 mgroup to IPv6 mgroup
Single static tree by PIM-SM
IPv6 RP in IPv6 backbone
PE-based static tree by PIM-SM (N trees totally)
One tree rooted by each PE
SPT rooted by each PE to all other PE

6. IPv4/v6 group mapping
(S,G)v4 <->(S’,G’)v6 ,S’ is IPv6 address of the PE of S
G’ is ff18:ssss:ssss:gggg:gggg::x
s and g are the (S,G)
P maintains M IPv6 group states if there are M IPv4 groups
(S,G)v4 <->(S’,G’)v6
(S,G)v4 <->(S’,G’)v6

7. Construct a single tree in IPv6 backbone
A single IPv6 group address is configure on RPv6 and PEs
Egress PE initiates a single join procedure to RPv6
SPT rooted by RPv6, IPv6 tree optimization is a problem
The number of IPv6 multicast groups is 1

8. Construct one tree rooted by each PE in IPv6 backbone
Each ingress PE has its own IPv6 group address
ingress PE sends its IPv6 group address to all other PEs by Softwire extensions
Egress PE initiates a join procedure to each ingress PE (SPT rooted by each PE)
The number of IPv6 multicast groups is N

9. IPv4 PIM-SM Sender/receiver Registration over IPv6 backbone
Source
S register
S tree

10. Multicast Forwarding
Source

11. Conclusion and future work
Construct multicast tree in IPv6 backbone
Dynamic mapped IPv6 tree (M trees)
Dynamically mapping IPv4 mgroup to IPv6 mgroup
Scalability problem in IPv6 core
Single static tree rooted by IPv6 RP
IPv6 tree optimization is a problem
PE-based static tree by PIM-SM (N trees totally)
One tree rooted by each PE
SPT rooted by each PE to all other PE
Scalability: Keep less states in the backbone
Efficiency: PE may receive some packets they do not require
Future work
Comments & co-authors are welcome
To be a WG document