Gigabit Ethernet standard delayed at least until June

Members of the Gigabit Ethernet Alliance (GEA) reluctantly admitted this week that the much-hoped-for March date for IEEE ratification of the key 802.3z Gigabit Ethernet standard will slip by at least three months.

That means vendors will have to wait until at least June, and maybe September or later, to call their Gigabit Ethernet products standards-compliant.

After meeting here for two days this week, the IEEE 802.3z subcommittee agreed that the outstanding issue of differential mode delay (DMD) was buggy enough to warrant more study. Everyone involved is hoping to come up with a solution that will work off the installed base of fiber. The worst case scenario would either force the IEEE to adopt a shorter distance than anticipated or cause transceiver and fiber vendors to change their products.

The problem relates to running traffic over multimode fiber more than 100 meters. The alliance had hoped to be able to ratify a standard for up to 260 meters. Now the alliance is looking at the fiber optics experts to come up with a conformance test that would ensure that Gigabit Ethernet will run over multimode fiber at a specified distance.

"There are parts that work and work well; it's just writing the specs and the proper screening procedures to be able to certify that what you have is within the parameters," said Bob Grow, a key member of the alliance and an engineer at XLNT Corp.

The GEA should know by the beginning of March at the next plenary meeting in Irvine, Calif., whether the standard will fall further behind.

Some network companies, such as 3Com Corp., lost no time last week in assuring customers they would guarantee any prestandard Gigabit Ethernet products would be upgraded to the standard for free if that becomes necessary. Industry observers are strongly advising customers to make sure their vendors are prepared to support a change in the standard.