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IPv4/IPv6 Coexistence Framework Prefixing/Encap/Translation (PET). draft-cui-softwire-pet-02 Yong Cui, Mingwei Xu, Jianping Wu, Xing Li, Chris Metz, etc. CERNET, CISCO Jul. 2010. Motivation: Diminish the disadvantage of translation. Host A (IPv4). Do we need translation? YES
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IPv4/IPv6 Coexistence Framework Prefixing/Encap/Translation (PET) draft-cui-softwire-pet-02 Yong Cui, Mingwei Xu, Jianping Wu, Xing Li, Chris Metz, etc. CERNET, CISCO Jul. 2010
Motivation: Diminish the disadvantage of translation Host A (IPv4) • 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 IPv4 Internet Xlate??? AFBR1 Dual-stackbackbone Xlate??? AFBR2 IPv6 Edgenetwork Host B (IPv6)
Processing Layer State Maintenance IPv4/IPv6 Routing Application Scenario Motivation Tunneling Translation • It is necessary to • decide which method should be used in given scenarios • how they collaborate for solving transition problems while utilizing both advantages? IP layer (Hardware) Stateless (Scalable) Separated routing (Scalable) E-IP over I-IP ALG (Software) Stateful (No Scalable) Routing merge (No Scalable) E-IP I-IP
IPv6 Backbone IPv4 Internet IPv6 Edge AFBR Xlate AFBR SW AFBR SW Softwire 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 IPv4 Internet IPv6 Edge AFBR Xlate PE
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.
PET framework ☆ ☆ ☆ E-IP Backbone • P: Prefixing • E: Encapsulation • T: Translation • IPv4 access • IPv6 access • Dual-stack access E-IP network PET PET E-IP network PET PET I-IP Backbone (Dual-stack) Host B Host C PET PET PET I-IP network Host A Edge Network Edge Network
Forwarding Xlate IPv6 Backbone IPv4 664 Remote Xlat Xlate+SW Decap IPv6 Edge net IPv4 664 Local-Xlat+SW IPv4 Encap. IPv6 Decap+Xlate 466 SW+Remote Xlat Function of PET PET Signaling IPv6 backbone source PET Dest PET IPv6 Encap. 464 SW IPv4 IPv4 Decap.
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
Future work • PET signaling will be defined by BGP extension based on Softwire • Leveraging other existing tunneling and translation technologies • Ask for accepting as WG document