25 Gigabit Ethernet: It works already, test event shows

The IEEE P802.3by 25Gb/s Ethernet Task Force advanced its specifications efforts to the Working Ballot stage this past July (see "Ethernet progresses on several fronts at July IEEE 802.3 plenary meeting"). But the technology got a workout the previous month when The Ethernet Alliance held a test event at the University of New Hampshire InterOperability Laboratory (UNH-IOL) in Durham, NH. Technology developers apparently are doing a good job of interpreting the Task Force's intentions; "greater than" 86% of the test cases performed to the current specifications, the Ethernet Alliance reports.

After an initial stumble and the ensuing creation of an industry alliance to take up the perceived slack (see "Efforts toward 25 Gigabit Ethernet specs stall at IEEE plenary" and "25 Gigabit Ethernet, 50 Gigabit Ethernet targets of industry consortium"), the IEEE began work on the 25-Gbps standard in 2014 (see "IEEE launches 25 Gigabit Ethernet Study Group"). The effort has moved quickly, but it appears that industry is keeping pace. Specifications for 100 Gigabit Ethernet that use 25-Gbps optical and electrical lanes are already in place, which may help account for the developers' success at this early stage.

"During our recent 40G/100G plugfest, we were testing equipment developed throughout the last five years. However, 25GbE is still at a nascent stage of the standardization process," noted Scott Kipp, president of the Ethernet Alliance and principal technologist at Brocade. "The array of pre-standard equipment and cables tested during our technical feasibility event showed an unanticipated level of maturity. It's a strong expression of the Ethernet ecosystem's continued commitment to interoperability and a sign of the industry's desire to capitalize on the benefits that 25-Gbps signaling offers."

The Ethernet Alliance says the June 22 technical feasibility event saw several devices and cabling put through hundreds of use cases that covered a wide range of issues, including link configuration, in-link configuration, target bit error ratio (BER) confidence, transmitter output waveform, and channel characterization. The group forwarded the test results to the P802.3by Task Force.

"Work on the IEEE P802.3by 25 Gb/s standard is progressing quickly, but having this data available has been highly beneficial to the development of the 25 Gigabit Ethernet standard," said Mark Nowell, chairman, IEEE P802.3by 25Gb/s Ethernet Task Force, and senior director of engineering, Cisco Systems. "The positive results generated at the Ethernet Alliance 25-Gbps feasibility event were very encouraging. I would like to thank the Ethernet Alliance for making this event a reality and bringing this data forward."

Vendors participating in the event included Amphenol Corp.; Arista Networks, Inc.; Cisco; Dell, Inc.; FCI; Hitachi, Ltd.; Intel Corp.; Ixia; Luxshare-ICT; Marvell Technology Group Ltd.; Mellanox Technologies Ltd.; Molex Inc.; QLogic Corp.; Spirent Communications Plc.; TE Connectivity Ltd.; and Xilinx, Inc.

The Alliance has compiled information from the 25 Gigabit Ethernet feasibility event, as well as the recent 40/100 Gigabit Ethernet plugfest, in a tech brief, "Commitment to Ethernet Interoperability," available on the group's website.

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