IEEE 802.1ah draft standard (IEEE802.1ah), also known as Provider Backbone Bridges (PBB), defines an architecture and bridge protocols for interconnection of multiple Provider Bridge Networks (PBNs - IEEE802.1ad QinQ networks). PBB is defined in IEEE as a connectionless technology based on multipoint VLAN tunnels. IEEE 802.1ah employs Provider MSTP as the core control plane for loop avoidance and load balancing. As a result, the coverage of the solution is limited by STP scale in the core of large service provider networks. The 7210 SAS-T in network mode supports a native PBB Ethernet backbone deployment.
The IEEE model for PBB is organized around a B-component handling the provider backbone layer and an I-component concerned with the mapping of Customer or Provider Bridge (QinQ) domain (for example, MACs, VLANs) to the provider backbone (for example, B-MACs, B-VLANs), that is, the I-component contains the boundary between the Customer and Backbone MAC domains. PBB encapsulates customer payload in a provider backbone Ethernet header, providing for Customer MAC hiding capabilities. With PBB, 7210 SAS platforms can be used for tier-1/2 aggregation, encapsulating customer service frames in PBB, allowing the PE-rs devices deployed in the metro core to be aware of only provider MAC addresses and for metro service scaling.
7210 SAS platforms fully support only native PBB deployment. They do not support the integrated PBB VPLS model. In particular, 7210 SAS platforms do not support use of SDPs in PBB services.