The desire for faster data centre optics appears to be outpacing the standards process. As a result, 22 companies have joined forces to speed up the development of 100Gb/s serial optical interfaces.
The 100G Lambda multi-source agreement (MSA) group is developing specifications for optical interfaces based on 100Gb/s per wavelength over duplex singlemode fibre. These new optical specifications are targeting 100 and 400 Gigabit Ethernet applications in the next-generation of networking equipment.
Currently, the most popular 100Gb/s optical standards rely on 25Gb/s optical lanes that align with 25Gb/s electrical interfaces on switching and routing chips in networking hardware. As the electrical interfaces on those chips increase in speed, it becomes necessary to increase the optical channel speeds to avoid additional cost that arises from needing to translate to slower speeds.
The new interfaces being defined by the 100G Lambda MSA will double the speed per wavelength and combine this with PAM-4 encoding and forward error correction (FEC) to achieve 100Gb/s on a single optical channel. A single optical lane of 100Gb/s has the potential to be at least 40 per cent lower in cost than four lanes of 25Gb/s, according to the group.
The initiative is intended to complement rather than circumvent the work currently being carried out IEEE P802.3. The new interfaces being defined by the 100G Lambda MSA are expected to be compatible with the IEEE’s 100GBASE-DR and 400GBASE-DR4 specifications for 500m optics, while focusing instead on the need for 2km and 10km reaches.
Participating MSA member companies are addressing the technical challenges and their collaboration will ensure interoperability for optical transceivers and interfaces produced by different manufacturers and in various form factors. The new specifications will be implementable in common industry form factors such as QSFP28 for 100Gb/s and QSFP-DD or OSFP for 400Gb/s.
“The consortium expects that the IEEE will initiate development of these important industry specifications in the future, and therefore the MSA members have chosen to very closely follow IEEE methodologies in their technical work with the hope that, when the IEEE initiates its work, they will be able to strongly leverage the work of the MSA,” the group said.
The 100G Lambda MSA Group founding members include: Alibaba, Arista Networks, Broadcom, Ciena, Cisco, Finisar, Foxconn Interconnect Technology, Inphi, Intel, Juniper Networks, Lumentum, Luxtera, Macom, MaxLinear, Microsoft, Molex, NeoPhotonics, Nokia, Oclaro, Semtech, Source Photonics, and Sumitomo Electric.
The MSA group anticipates that its initial specification will be released before the end of the year, and the final version completed by mid-2018.
Though the consortium has no current plans to define interfaces beyond 400Gb/s, its work lays the foundation for higher speeds based upon multiple lanes of 100Gb/s. If the commercial need emerged, then the consortium could extend its scope.
