IEEE 802.1ah-2008 PDF
The scope of this standard is to define an architecture and bridge protocols compatible and interoperable with Provider Bridged(1) Network protocols and equipment allowing interconnection of multiple Provider Bridged Networks, to allow scaling to at least 2^20 Service VLANs, and to support management including SNMP.
This standard will complete the future work identified by P802.1ad, by providing a specific means for interconnecting Provider Bridged Networks. It will enable a Service Provider to scale the number of Service VLANs in a Provider Network by interconnecting the Service Virtual LANs, and provide for interoperability and consistent standards based management.
Amendment Standard – Superseded. This amendment defines an architecture and bridge protocols for interconnection of multiple Provider Bridged Networks, allowing a Provider to support up tot 2^20 service instances.