Mar 5 2014
Optical Internetworking Forum (OIF) members approved revision 3.1 of the Common Electrical Interface (CEI) implementation agreement document (link to CEI document), which specifies the electrical characteristics of transmitters, receivers, and channels for interface speeds up to 28 Gb/s.
The latest revision of this IA is key to addressing the challenges of 100G technology and includes two new clauses defining additional CEI-28G interfaces that are currently being implemented in products today by suppliers.
“The OIF has focused on keeping the CEI IA up-to-date and forward looking,” said David Stauffer, of Kandou and the OIF Physical and Link Layer working group chair and board member. “These new interface definitions are important as the industry is currently deploying 100G applications and needs to continually support faster and more cost-effective electrical interfaces to optical components.”
CEI-28G-VSR specifies a chip-to-module electrical interface for use in the range 19.6 Gsym/s to 28.1 Gsym/s, with up to 10 dB of loss and a single connector. This clause of the implementation agreement defines the characteristics required to communicate between an optical module and a host chip and meet interoperability requirements at the module connector. CEI-28G-VSR is the definitive module interconnection for the 28G generation and has been implemented by several optical module products.
CEI-28G-MR defines requirements for a chip-to-chip medium reach high-speed electrical interface between nominal baud rates of 19.90 Gsym/s and 28.1 Gsym/s with 20 dB of loss. Past work from the OIF found the need for a specification optimized for medium reach, shorter length backplane channels with lower loss. Transmitters and receivers optimized to meet CEI-28G-MR and used in medium reach applications will offer power advantages over components designed for higher loss backplanes. The CEI-28G-MR signals the completion of the 28G IAs.