Members of the two RPR camps explained their positions at a Tuesday (Oct. 2) session on new packet architectures, but emphasized that the dispute hasn't disrupted the group's schedule.

In sessions held over the past year and a half, proposals for the RPR standard have been presented to what is now the IEEE 802.17 working group. The latest round of meetings — held in San Jose, Calif., during the week of the Sept. 11 terrorist attacks — left the group with two complete proposals for the standard.

Cisco Systems Inc. reportedly made an early bid to use its proprietary dynamic packet transport (DPT) as the basis for the standard, but the router giant was answered by an alliance of companies, generally referred to as "the coalition," that crafted an opposing proposal.

The 802.17 membership is split roughly evenly between the groups, producing a standstill. "Neither group has the 75 percent vote to approve a technical standard, so we're trying to drive the groups to a compromise," said Lauren Schlicht, product line manager at Mindspeed Technologies.

The proposals are similar in concept, presenting a protocol that uses fiber-ring bandwidth more efficiently than does Sonet. The crux of the issue is whether RPR should rely on Internet Protocol routers, as Cisco suggests, or whether it should stick to Layer 2 transport.

Ready to fight

In the same Tuesday session, 802.17 group chairman Howard Frazier noted that clashes in a standards effort are normal, particularly when multiple vendors have already shipped pre-standard products. Cisco's DPT technology is already being used in live networks, but the same is true for technology from coalition members Nortel Networks and Luminous Networks Inc. "If Cisco were to go away and take DPT off the table, the coalition would start fighting among themselves," Frazier said.

The 802.17 group is sticking by its timetable to vote on a standard by the spring of 2002, but even that wait might be too long for some vendors, particularly given the group's friction. In a separate CDC session, chief technical officer Kris Shankar of Metro-Optix Inc. noted that RPR's reliance on a new media-access controller [MAC] could be a handicap. Other protocols such as Gigabit Ethernet were quick successes precisely because they used an existing Ethernet MAC, he said.

But supporters of RPR aren't worried that the technology might be supplanted before the standard arrives.

"There's not a major carrier in the U.S. that doesn't already have a program in place to adopt RPR," said Jay Shuler, vice president of marketing for Luminous.

The next 802.17 meeting will be during the IEEE plenary sessions in Austin, Texas, Nov. 12-16.

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