1. Softwire Mesh Example CERNET2 Xing Li

2. Outline  CERNET2 Briefing  CERNET2’s IPv4 over IPv6 requirement  Configurations  Summary

3. CERNET2 Briefing  CERNET2 is the largest backbone of CNGI project  CERNET2 is running on top of CERNET Transport network  CERNET2 is a “pure IPv6” backbone  The users of CERNET2 require high performance IPv4 applications

4. CNGI Backbones

5. CERNET Transport Network 大连大连 北京北京 郑州郑州 石家 庄 武汉武汉 合肥合肥 南京南京 上海上海 长沙长沙 南昌南昌 杭州杭州 广州广州 福州福州 成都成都 昆明昆明 重庆 厦门厦门 海口海口 桂林 沈阳沈阳 哈尔滨哈尔滨 天津天津 济南济南 南宁南宁 深圳 太原 太原 青岛 BJ zhzXA CDWH GZxmn hzh SHNJhef dln SYchchrb chq chs 大连大连 北京北京 郑州郑州 石家 庄 武汉武汉 合肥合肥 南京南京 上海上海 长沙长沙 南昌南昌 杭州杭州 广州广州 福州福州 成都成都 昆明昆明 重庆 厦门厦门 海口海口 桂林 沈阳沈阳 哈尔滨哈尔滨 天津天津 济南济南 南宁南宁 深圳 太原 太原 青岛 BJ zhzXA CDWH GZxmn hzh SHNJhef dln SYchchrb chq chs tjn jnn lzh

6. CERNET2 IPv6 Technical Specification  25 Pops in 20 cities linked via 2.5Gbps to 10 Gbps trunks  IPv6 only Backbone  AS23910  2001:DA8::/32  IGP - OSPFv3  EGP - BGP4+ peering with 25 regional Pops 5 CNGI backbones CERNET IPv6, CJ-IPv6, NSFCNET, 863-testbed, 3Tnet, etc  100+ access networks

7. CERNET2 Topology

8. CERNET2 Peering

9. CERNET2 ’ s IPv4 over IPv6 App. Requirement High Throughput Video Multicast Video

10. CERNET2 ’ s Vision  IPv4 over IPv6 may help  Built and/or upgrade a backbone without worrying the limited IPv4 address, have a better performance-to-cost ratio and in a “politically correct” manner  Support existing IPv4 access networks  Support existing IPv4 applications  And it may help for the transition from IPv4 to IPv6 in a cost effective, incremental and seamless fashion

11. Configuration (1) v4 BJ GZ SH Only BJ, SH and GZ provide IPv4 service Other nodes are IPv6 only Allow manual configuration Must support unicast and multicast Global IPv4 Internet

12. Configuration (2) v4 BJ GZ SH All Pops provide IPv4 service hzh xmn WHNJ hrf jnn SY dln chchrb zhz XA CDSHchq lzh v4 Prefer auto-configuration Must support unicast and multicast chs tjn v4 Global IPv4 Internet

13. Access Network ’ s View CERNET2 Backbone edge IPv4 Access IPv6 Access IPv4 static or eBGP peering Encapsulation and Setup Same as a dual-stack backbone Pure IPv6 backbone softwire

14. Softwire Mesh Scenarios (IPv4/IPv6) IPv6 Transit AFBR IPv4 access island IPv4 access island IPv4 access island IPv4 access island IPv6 access IPv4 static or eBGP peering Encapsulation and Setup Same behavior as a dual-stack backbone softwire

15. Softwire Mesh Scenarios (IPv6/IPv4) IPv4 Transit AFBR IPv6 access island IPv6 access island IPv6 access island IPv6 access island IPv4 access IPv6 static or eBGP peering Encapsulation and Setup Same behavior as a dual-stack backbone Softwire

16. Notes  Typical number of Ps, PEs, and CPEs?  P20 (today) : 50 (CERNET2)  PE10 (today) : 100 (CERNET2)  CPE100 (today) : X0000 (CERNET2)  Why not use CPE to provide the functionality?  ISP business considerations  Why not use layer 2 service?  Point to point scalability and multi-point to multi-point broadcast storm  Configuration on operational overhead  Mesh problem more similar to L3 VPN case  Why not run dual stack on P routers  Political and economical considerations  Need to get to V6 only network

17. Summary  IPv4 over IPv6 service should support  The IPv4 access network should behave as if it is connected to a IPv4 or dual-stack backbone  It should support both IPv4 unicast and multicast  Initial requirement is inside an AS domain, but if possible, cross AS’s mechanism is desirable  Encapsulation and control protocol includes  Encapsulation type  End point setup  MTU  Management requires  MIB