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Multicast Extensions to DS-Lite Technique in Broadband Deployments draft-qin-softwire-dslite-multicast- 03. Q. Wang, J . Qin , P. Sun, M. Boucadair, C. Jacquenet, and Y. Lee, . Context & Use Cases. Context
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Multicast Extensions to DS-Lite Technique in Broadband Deployments draft-qin-softwire-dslite-multicast-03 Q. Wang, J. Qin, P. Sun, M. Boucadair, C. Jacquenet, and Y. Lee,
Context & Use Cases • Context • Deliver multicast-based service offerings to DS-Lite serviced customers in ASM and SSM modes • Use Cases • IPv4 receiver accessing to IPv4-formatted multicast content • Dual-Stack receiver accessing to IPv4-formatted multicast content
Foundations • Address Building • Use [I-D.boucadair-behave-64-multicast-address-format] to build multicast IPv4-embeded IPv6 addresses • Use [RFC6052] to build unicast IPv4-embeded IPv6 addresses representing IPv4 sources in the IPv6 realm • The underneath network delivers encapsulated packets in standard multicast fashion • L2 optimization functions can be used • All involved interworking functions are stateless
S QR DR R mB4 mAFTR MLD Querier IPv4 Receiver IPv4 Source IGMP MLD IPv6 PIM IPv4 PIM Stateless IPv4-IPv6 PIM Interworking Function Stateless IGMP-MLD Interworking Function IPv4 Flows IPv4-in-IPv6 Flows IPv4 Flows IPv6 Realm IPv4 Realm IPv4 Realm Stateless de-encapsulation of multicast flows Stateless encapsulation & IPv4 -> IPv6 header mapping of multicast flows CPE Overall procedures with involved interworking functions: Need to provision the mB4 with mPREFIX64 and uPREFIX64
S QR DR R mB4 mAFTR MLD Querier IPv4 Receiver IPv4 Source IGMP MLD IPv6 PIM IPv4 PIM Stateless IPv4-IPv6 PIM Interworking Function Stateless IGMP-MLD Interworking Function IPv4 Flows IPv6 Flows IPv4 Flows IPv6 Realm IPv4 Realm IPv4 Realm Stateless NAT Stateless NAT CPE A NAT-based flavor can be also considered but this may require to assess the information loss and the performance impact on the CPE
R S QR DR DS Receiver mB4 mAFTR MLD Querier IPv4 Source MLD IPv6 PIM IPv4 PIM Stateless IPv4-IPv6 PIM Interworking Function Stateless address synthesis IPv4-in-IPv6 Flows IPv4 Flows IPv6 Realm IPv4 Realm Stateless de-encapsulation of multicast flows Stateless encapsulation & IPv4 -> IPv6 header mapping of multicast flows CPE mB4 is embedded in the receiver host (e.g., STB). This mode is suitable for deployments using CPEs with low resources
Multicast Routing • ASM Mode: Building shared trees • In the IPv4 side: Transparent • In the IPv6 side • For the sake of simplicity, it is RECOMMENDED to configure an mAFTR as the RP for IPv4-embedded IPv6 multicast groups • Otherwise, it may require an mAFTR to emulate the PIM Source Register procedure on behalf of IPv4-embedded IPv6 sources with the RP • The PIM Source Register procedure in the IPv4 domain is not altered • SSM and SPT modes are supported
Fall-Back Mode • If MLD is not activated on mB4, and if this is allowed in the CPE, multicast flows may be exchanged in a Fall-Back mode • Based on the Unicast DS-Lite architecture where the IGMP messages are encapsulated and transmitted through the tunnel • The AFTR will perform the IGMP Querier function • The Fall-Back mode is not optimal if the unicast AFTR is not the first IP node. • When the AFTR is not located in the first IP node, this mode is NOT RECOMMENDED
Next Step • Comments? • http://tools.ietf.org/html/draft-qin-softwire-dslite-multicast-03