I-TAG A multiplexing tag for service instance scaling in Provider Bridged Networks Mick Seaman mick_seaman@ieee.org

Service instance multiplexing I-TAG Purpose Architecture Format Context 802.1 July ‘04 Service instance multiplexing

Service instance multiplexing ITAG : Purpose Allow upto 220 service instances in a PBN Particularly to address the E-LINE reqmt Use for E-LAN, E-TREE optional/as reqd (more later on benefits of choice) Leverages existing solutions Complements .1Q, .1ad, .1D GVRP, GMRP No major new protocols required for scaling 802.1 July ‘04 Service instance multiplexing

Service instance multiplexing ITAG : Architecture I-tagging systems are “end-stations” on a provider backbone or core network. The backbone can be either bridged (.1D) or virtual bridged (.1Q /.1ad) If backbone is .1Q then tagging, detagging (ingress and egress) rules are exactly as they are today Tag can be added/not added and tag value dependent on frame C-VID just as for “dual bridge model” in .1Q <<see Paul Bottorff’s slides from Monday for diagram>> 802.1 July ‘04 Service instance multiplexing

Service instance multiplexing I-TAG : Format (1) I-TAG EtherType (16 bits) I-TAG TCI (Tag Control Info, i.e. version, flags 8 bits) PRI/DE (priority, drop eligible 4 bits) SID (Service Instance ID – 20 bits) User DA (Destn. Address of conveyed ‘frame’ – 48 bits) User SA (Source Address of conveyed ‘frame’ – 48 bits) 16 + 128 bits total 802.1 July ‘04 Service instance multiplexing

Service instance multiplexing I-TAG : Format (2) 802.1 July ‘04 Service instance multiplexing

Service instance multiplexing I-TAG : Context 802.1 July ‘04 Service instance multiplexing