OIF Launches CEI-112G Projects, Forms Network Operator Working Group

The Optical Internetworking Forum (OIF) announced that it has begun work on long reach (LR) and medium reach (MR) CEI-112G, building upon two existing 100G serial electrical link projects. Forum members continue to support and approve the development of projects addressing CEI-112G as bandwidth needs increase. Dr. Chongjin Xie of Alibaba was invited to present to members at the quarterly meeting in Shanghai. Dr. Xie shared with members the need for various network technologies, innovations and breakthroughs for datacenters. Following the meeting, the members participated in an OIF Day with China Unicom and SK Telecom.

CEI-112G Projects

The CEI-112G-LR project defines an interface to enable high-loss 112G backplane channels. This project will also facilitate direct attach copper (DAC) cable channel links at 112G. The CEI-112G-MR project will develop specifications for a chip-to-chip (c2c) interface which can also be used to support applications of 112Gx2 (224G), and 112Gx4 (448G) with reduced power, complexity, and enhanced density.

“These projects build upon the relevant and foundational 56G and 112G CEI roadmap the OIF has established,” said Nathan Tracy of TE Connectivity and OIF vice president of marketing.  “The industry continues to look to the OIF to deliver interoperable implementation agreements that will drive adoption of both 100 Gb/s serial applications and the interfaces needed to address higher bandwidth.”

Network Operator Working Group

Members voted to evolve the Carrier Working Group into the new Network Operator Working Group, reflecting the active participation of web-scale and content service provider members such as Alibaba, Google and Microsoft, along with traditional service providers such as China Telecom, Orange, TELUS, and Verizon.

“The new working group reflects the OIF’s growing membership of network operators who are participating in technology advancement and interoperability demonstrations to influence the industry,” said Dr. Junjie Li of China Telecom, the newly elected Network Operator Working Group chair.  “These network operators have driven the OIF 400ZR and CFP2-DCO projects and are sharing their insights as reflected in the presentation from our Q4 speaker, Dr. Xie of Alibaba.”

OIF Election Results

Cathy Liu of Broadcom Limited and Dr. Martin Bouda of Fujitsu were newly elected to the Board for one-year terms, with Dr. Bouda appointed to secretary/treasurer. Ian Betty of Ciena was re-elected for a two-year term, and Tad Hofmeister of Google was elected to a two-year term.

Jonathan Sadler of Coriant was appointed to vice president. Dave Brown of Nokia continues to serve as president, and Nathan Tracy of TE Connectivity continues to serve as vice president of marketing.

About the OIF
The OIF facilitates the development and deployment of interoperable networking solutions and services. Members collaborate to drive Implementation Agreements (IAs) and interoperability demonstrations to accelerate and maximize market adoption of advanced internetworking technologies. OIF work applies to optical and electrical interconnects, optical component and network processing technologies, and to network control and operations including software defined networks and network function virtualization. The OIF actively supports and extends the work of national and international standards bodies. Launched in 1998, the OIF is the only industry group uniting representatives from across the spectrum of networking, including many of the world’s leading service providers, system vendors, component manufacturers, software and testing vendors. Information on the OIF can be found at


The OIF’s 400ZR coherent interface starts to take shape

Roy Rubenstein, Gazzetabyte

June 23, 2017

The Optical Internetworking Forum’s (OIF) group tasked with developing two styles of 400-gigabit coherent interface is now concentrating its efforts on one of the two.

When first announced last November, the 400ZR project planned to define a dense wavelength-division multiplexing (DWDM) 400-gigabit interface and a single wavelength one. Now the work is concentrating on the DWDM interface, with the single-channel interface deemed secondary.

“It [the single channel] appears to be a very small percentage of what the fielded units would be,” says Karl Gass of Qorvo and the OIF Physical and Link Layer working group vice chair, optical, the group responsible for the 400ZR work.

The likelihood is that the resulting optical module will serve both applications. “Realistically, probably both [interfaces] will use a tunable laser because the goal is to have the same hardware,” says Gass.

The resulting module may also only have a reach of 80km, shorter than the original goal of up to 120km, due to the challenging optical link budget.

Origins and status

The 400ZR project began after Microsoft and other large-scale data centre players such as Google and Facebook approached the OIF to develop an interoperable 400-gigabit coherent interface they could then buy from multiple optical module makers.

The internet content providers’ interest in an 80km-plus link is to connect premises across the metro. “Eighty kilometres is the magic number from a latency standpoint so that multiple buildings can look like a single mega data centre,” says Nathan Tracy of TE Connectivity and the OIF’s vice president of marketing.

Since then, traditional service providers have shown an interest in 400ZR for their metro needs. The telcos’ requirements are different to the data centre players, causing the group to tweak the channel requirements. This is the current focus of the work, with the OIF collaborating with the ITU.

“The catch is how much can we strip everything down and still meet a large percentage of the use cases”

“The ITU does a lot of work on channels and they have a channel measurement methodology,” says Gass. “They are working with us as we try to do some division of labour.”

The group will choose a forward error correction (FEC) scheme once there is common agreement on the channel. “Imagine all those [coherent] DSP makers in the same room, each one recommending a different FEC,” says Gass. “We are all trying to figure out how to compare the FEC schemes on a level playing field.”

Meeting the link budget is challenging, says Gass, which is why the link might end up being 80km only. “The catch is how much can we strip everything down and still meet a large percentage of the use cases.”

400ZR form factors

Once the FEC is chosen, the power envelope will be fine-tuned and then the discussion will move to form factors. The OIF says it is still too early to discuss whether the project will select a particular form factor. Potential candidates include the OSFP MSA and the CFP8.

“The cloud is the biggest voice in the universe”

The industry assumption is that the 80km-plus 400ZR digital coherent optics module will consume around 15W, requiring a very low-power coherent DSP that will be made using 7nm CMOS.

“There is strong support across the industry for this project, evidenced by the fact that project calls are happening more frequently to make the progress happen,” says Tracy.

Why the urgency?

“The cloud is the biggest voice in the universe,” says Tracy. To support the move of data and applications to the cloud, the infrastructure has to evolve, leading to the data centre players linking smaller locations spread across the metro.

“At the same time, the next-gen speed that is going to be used in these data centres – and therefore outside the data centres – is 400 gigabit,” says Tracy.