IEEE 802.1aq control of the Mac-in-Mac Hash/TTL B-VID(s) Jan 2011 Peter Ashwood-Smith

2 Background 802.1aq creates new behavior for a B-VID. Traffic on a B-VID within an 802.1aq domain travels shortest path towards its B-DA, very different than normal PBB use. –No learning/Output by computation –Ingress Check/Discard if incorrect Therefore 802.1aq has mechanisms to ensure B-VID function is agreed to within the 802.1aq domain. To change the function, add or delete a new B- VID 802.1aq has mechanisms to advertise and verify consistency.

3 Background The function of a B-VID is defined with a tuple: {, } The is further broken down into a world wide unique OUI and local index aq currently defines 17 values all with the OUI. These are indexes Index 0 is for a shared tree (CIST) while indexes are for SPF trees with different tie breakers.

4 Tuples are exchanged and verified :1 :2:3 :4 :5:6 B-VID,ECT-ALGORITHM tuples Are exchanged in hellos and checked for consistency. B-VID,ECT-ALGORITHM tuples are also advertised in LSPs. Inconsistency is only permitted if a tuple is not in use. We can therefore introduce a new B-VID, ECT-ALGORITHM and temporary inconsistency is allowed until we start using it. We can therefore remove all services from a B-VID, ECT-ALGORITHM and then start to delete it and inconsistency is allowed while I delete it. Migration to a new B-VID, ECT-ALGORITHM or away from one then only requires edge by edge re-provisioning, can be done over days/weeks.

5 Algorithm to B-VID association in Hello |Type= SPB-B-VID| = | Length | (1 byte) | ECT - VID Tuple (1) (6 bytes) | | | | ECT - VID Tuples (N) (6 bytes) | | ECT - Algorithm (32 bits) | | Base VID (12 bits) |U|M|RES|

6 Algorithm to B-VID association in LSP |Type = SPB-Inst| = | Length | (1 byte) | CIST Root Identifier (4 bytes) | | CIST Root Identifier (cont) (4 bytes) | | CIST External ROOT Path Cost (4 bytes) | | Bridge Priority | (2 bytes) |R R R R R R R R R R R|V| SPSOURCEID | | Num of Trees | (1 bytes) | VLAN-ID (1) Tuples (8 bytes) | | VLAN-ID (N) Tuples (8 bytes) |

7 TLV – SPB-Service Instance |Type = SPBM-SI | = | Length | (1 byte) | B-MAC ADDRESS | | B-MAC ADDRESS (6 bytes) | Res. | Base-VID (12 bits) | |T|R| Reserved | ISID #1 | |T|R| Reserved | ISID #2 | |T|R| Reserved | ISID #n | A service is assigned to an ALGORITHM indirectly through association with a Base-VID. The Base-VID of course is part of an ALGORITH,VID tuple.

8 Suggested approach for ECMP Assuming an 802.1aq network running some number of ECT-ALGORITHMS. A new B-VID, ECT-ALGORITHM tuple is assigned and advertised normally. The new B-VID, ECT-ALGORITHM would cause hash based forwarding/TTL decrement for UNICAST traffic only. Migration to/from this B-VID would be identical to any other B-VID running an AQ forwarding plane.

9 Possible ECMP encodings ECT-ALGORITHMUCAST BEHAVIORMCAST BEHAVIOR C2-00CIST C2-01SPF low path id C2-02SPF low mask 0xFF …. …… C2-10SPF low mask 0xEE C2-11ECMP hash alg#1SPF low path id C2-12ECMP hash alg#1SPF low mask 0xFF ……… C2-20ECMP hash alg#1SPF low mask 0xEE C2-21ECMP hash alg#2SPF low path id C2-22ECMP hash alg#2SPF low mask 0xFF ……… C2-30ECMP hash alg#2SPF low mask 0xEE

10