1. IPv4/IPv6 Coexistence Framework Prefixing/Encap/Translation (PET) draft-cui-softwire-pet-01 draft-cui-softwire-pet64-00 Yong Cui, Mingwei Xu, Shengling Wang, Jianping Wu, Xing Li, Chris Metz, etc. CERNET, CISCO Nov. 2009

2. Motivation: Diminish the disadvantage of translation Do we need translation? YES We have spent years to reduce the complexity of translation –SIIT, NAT-PT, … –IVI, NAT64, DNS64, … Why not look at finding the right place to diminish the disadvantage of translation? –Even using an additional tunnel IPv6 Edge network Host B (IPv6) Dual-stack backbone IPv4 Internet Xlate ??? Host A (IPv4) AFBR1 AFBR2

3. Motivation IP layer (Hardware) Stateless (Scalable) Separated routing (Scalable) E-IP over I-IP Tunneling ALG (Software) Stateful (No Scalable) Routing merge (No Scalable) E-IP  I-IP Translation Processing Layer State Maintenance Application Scenario It is necessary to –decide which method should be used in given scenarios –how they collaborate for solving transition problems while utilizing both advantages? IPv4/IPv6 Routing

4. Example to combine them In the beginning of small IPv6 network Next step on large IPv6 backbone Incremental deployment for 100 IPv6 edge networks –Optionally xlate on either side How can network decide where to use tunneling or xlate IPv6 Backbone IPv6 Edge IPv4 Internet AFBR Xlate PE IPv6 Backbone IPv6 Edge IPv4 Internet Softwire AFBR SW AFBR SW AFBR Xlate

5. PET framework P: prefixing –all transition operations of control plane involved with subnet prefix For tunneling: prefix announcement, tunnel endpoint discovery/selection, and so on For translation: prefix configuration or address mapping policy, and so on E: encapsulation –all tunneling operations of data plane Encapsulation/decapsulation/MTU processing T: translation –all translation operations of data plane address mapping/protocol translation/MTU processing.

6. I-IP Backbone (Dual-stack) E-IP network PET PET framework PET E-IP Backbone PET I-IP network PET Edge Network IPv4IPv6IPv4IPv6

7. source IPv4 4  6  4 SW Function of PET PET Encap. IPv6 backbone IPv6 PET Decap. IPv4 PET Signaling Dest IPv6 Edge net Xlate+SW Decap IPv4 6  6  4 Local-Xlat+ SW IPv6 Backbone IPv4 6  6  4 Remote Xlat Forwarding Xlate IPv4 Encap. Decap+ Xlate IPv6 4  6  6 SW+ Remote Xlat

8. PET signaling Functionality –Negotiate between PET boxes –Who should do translation / tunneling –For what kind of packets / prefix Example –Negotiate the translation preference (TP) –Parameters: Bandwidth, pps, load –Stateless/Stateful

9. PET: Softwire + Behave (1:1/IVI) IPv6 Campus IPv6 Backbone IPv4 Internet PET2 DNS6DNS4 IVI prefix(P_ivi)+IPv4 Address allocation PET1 IVI mapped IPv4 prefix IPv4 Internet prefix Softwire routing [ P_ivi+ IPv4 prefix ] [ P_ivi+ (0.0.0.0/0) ] IPv6 native routing DNS process IPv6 packet Src: remove P_ivi Dst: remove P_ivi IPv4 packet Softwire vif + Xlate IPv6 interface for IPv6 dst TP1 lose TP2 win IPv4 packet Src add P_ivi Dst add P_ivi IPv6 packet Softwire vif for IPv4 dst IPv6 interface for IPv6 dst TP2 win √√ TP1TP2 PET signaling √

10. PET: Softwire + Behave (1:1/IVI) IPv6 Campus IPv6 Backbone IPv4 Internet PET2 DNS6DNS4 IVI prefix(P_ivi)+IPv4 Address allocation PET1 DNS process Remove P_ivi TP1 win 4over6 Softwire IPv6 packet IPv4 packet Decap Softwire vif + Xlate IPv6 interface for IPv6 dst TP2 lose IPv4 packet IPv6 packet Decapsulation Add P_ivi 4over6 Softwire Softwire vif for IPv4 dst IPv6 interface for IPv6 dst IVI mapped IPv4 prefix IPv4 Internet prefix Softwire routing [ P_ivi+ IPv4 prefix ] [ P_ivi+ (0.0.0.0/0) ] IPv6 native routing √√ TP1TP2 PET signaling √

11. PET: Softwire + Behave (1:N) IPv6 Backbone IPv4 Internet PET2 DNS6 DNS4 IPv6 address allocation PET1 DNS process TP2 win TP1 lose IPv6 packet Src: IPv6 addr+port => PET2 v4 addr + port Dst: remove P_ivi IPv4 packet Softwire vif + Xlate IPv6 interface for IPv6 dst TP2 win Src: add P_ivi Dst: port=> IPv6 addr+port IPv4 packet IPv6 packet Softwire vif for IPv4 dst IPv6 interface for IPv6 dst IVI mapped IPv4 prefix IPv4 Internet prefix Softwire routing [ P_ivi+ IPv4 prefix ] [ P_ivi+ (0.0.0.0/0) ] IPv6 native routing √√ TP1TP2 PET signaling √ IPv6 Campus

12. PET: Softwire + Behave (1:N) IPv6 Campus IPv6 Backbone IPv4 Internet PET2 DNS6DNS4 IPv6 address allocation PET1 DNS process Src: IPv6 ddr+port =>PET1 v4 addr + port Dst: remove P_ivi TP1 win 4over6 Softwire IPv6 packet IPv4 packet Decap Softwire vif + Xlate IPv6 interface for IPv6 dst TP2 lose IPv4 packet IPv6 packet Decapsulation; Src: add P_ivi Dst: port=> IPv6 addr+port 4over6 Softwire Softwire vif for IPv4 dst IPv6 interface for IPv6 dst IVI mapped IPv4 prefix IPv4 Internet prefix Softwire routing [ P_ivi+ IPv4 prefix ] [ P_ivi+ (0.0.0.0/0) ] IPv6 native routing √√ TP1TP2 PET signaling √

13. Future work PET signaling will be defined by BGP extension based on Softwire Leveraging other existing tunneling and translation technologies