The agreement, MEF 22, is being presented to the world via a press conference this morning. (See MEF Standardizes Backhaul.)
It doesn't include everything yet. Long Term Evolution (LTE), for example, isn't completely standardized, so it's not included in MEF 22 at first. The idea, as with previous MEF work, was to build the agreement around established standards, says Carlos Benavides, an MEF marketing co-chair who's also group manager of Metro Ethernet for Verizon Communications Inc. (NYSE: VZ).
What is included in MEF 22 are many of the basics to keep backhaul deployments consistent among equipment vendors and service providers:
- Specifications for operations, administration, and maintenance (OAM), based on established standards like International Telecommunication Union (ITU) Y.1731
- Class-of-service definitions
- A general recommendation for how to handle fault protection, to keep up the reliability of the backhaul connection
- Four usage cases, provided as examples of typical backhaul scenarios
The MEF is already planning for Phase 2 of MEF 22, because there's plenty that's still left out of the agreement. As noted, LTE will need to get folded in later; it's still not even clear how difficult that will be.
"Some people say LTE will be more complicated for backhaul; some people say LTE will be less complicated for backhaul. We need to find out what the requirements are," says Carsten Rossenhövel, another MEF marketing co-chair and managing director of the European Advanced Networking Test Center AG (EANTC) .
Likewise, some more options for timing and synchronization are being left for Phase 2, including the phase synchronization that's going to be necessary for LTE. Without it, Rossenhövel notes, the multiple signals in LTE's multiple-input/multiple-output (MIMO) architecture could cancel one another out.
Many Ethernet backhaul deployments base their timing information on external clocks, taken from GPS sources or TDM feeds. While that's a perfectly valid option, the MEF has decided it won't be included in MEF 22. The implementation agreement is going to stick to packet-based timing options, Benavides says.
— Craig Matsumoto, West Coast Editor, Light Reading