Ethernet Connectivity Fault Management

The IEEE and the ITU-T have cooperated to define the protocols, procedures and managed objects to support service-based fault management. Both IEEE 802.1ag standard (Ethernet Connectivity Fault Management (ETH-CFM)) and the ITU-T Y.1731 recommendation support a common set of tools that allow operators to deploy the necessary administrative constructs, management entities and functionality. The ITU-T has also implemented a set of advanced ETH-CFM and performance management functions and features that build on the proactive and on-demand troubleshooting tools.

CFM uses Ethernet frames and is distinguishable by Ethertype 0x8902. In certain cases, the different functions use a reserved multicast address that can also be used to identify specific functions at the MAC layer. However, the multicast MAC addressing is not used for every function or in every case. The Operational Code (OpCode) in the common CFM header is used to identify the type of function carried in the CFM packet. CFM frames are only processed by IEEE MAC bridges. With CFM, interoperability can be achieved between different vendor equipment in the service provider network up to and including customer premise bridges.

IEEE 802.1ag and ITU-T Y.1731 functions that are implemented are available on the 7210 SAS platforms.

The following table lists the CFM-related acronyms used in this section.