Strides made on standard for 10G over multimode

Earlier this year I mentioned that the IEEE was beginning to look at a standard for 10 Gigabit Ethernet over FDDI-grade multimode fiber. That effort continues to advance.

Now called the IEEE 802.3aq 10GBase-LRM Task Force, the group looking at creating a standard has had its project authorization request approved and has set forth its goals.

The idea is that a lower-cost fiber option for 10 Gigabit is necessary for the technology to take root in enterprise companies. Plus, if more Gigabit Ethernet connections are used, and if the number of devices connecting to enterprise networks continues to increase, eventually you need 10 Gigabit to aggregate those connections.

The task force wants to use the FDDI-grade fiber-optic lines that many companies already have installed. The group will define the physical layer specification that can make that happen, using the current MAC.

The target distance to be supported is at least 220 meters on installed 500 MHz*km multimode fiber, and the group says it will “enable migration to smaller form factor pluggable modules.”

There seems to be a good deal of interest in the group’s efforts. The task force says in its “5 Criteria” – an IEEE document to support a group’s reason for being – that 156 vendor and user representatives attended the call-for-interest meeting late last year, 30 technical contributions were put forth in the group’s January meeting, and 40 companies have said they would participate in the development of a standard. Contributions have been received from end users, industry experts and physical-layer, system and cabling vendors.

Specific costs haven’t been spelled out. However, the 5 Criteria document says the group believes it can get costs to the “3x-4x cost vs. 10x performance guidelines applied to comparable previous advanced Ethernet standards.” In other words, equipment based on the standard might cost three or four times as much as equipment based on Gigabit Ethernet, but it would have 10 times the performance.