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Copper 10 Gig inches closer to market

Dec 02, 20032 mins

* IEEE groups prep 10 Gigabit Ethernet over copper wiring

The two groups in the IEEE working on making 10 Gigabit Ethernet over copper wiring a reality – and a standard – continue to make great strides.

The first of the groups, the 10GBase-CX4 Task Force, is hoping that Draft 5.3 of its document will be the last. After the usual rounds of comments and concerns, the group says it should be ready to get the standard ratified in January.

The 10GBase-CX4 specification, or IEEE 802.3ak, is intended to send 10 Gigabit Ethernet over twinaxial copper cables. Distances would be limited to 15 meters or less, meaning that equipment supporting the standard really could only be used within a data center, perhaps to interconnect servers.

The technology being developed by the second group, the 10GBase-T Study Group, recently acquired the designation IEEE 802.3an. This specification would be used to run 10 Gigabit Ethernet over copper wiring as well – twisted pair wiring that is similar to the widely installed Category-5 cables.

Back in September I mentioned that this study group was weighing two different options for the standard – one favored speed at the expense of distance and the other favored distance at the expense of speed.

It appears the group has decided on the former. That is, the speed will remain true to 10G bit/sec, but the specified distance will vary.

The distance depends on the cabling used. Don’t try to run this over ordinary Cat-5 cables; Cat-6 or Cat-7 are really needed to get reasonable distances. The group is aiming to get distances of at least 100 meters over Cat-7, and at least 55 meters over Cat-6. If you used Cat-5E, you’d be pushing the cabling beyond its specified frequency range.

Applications for 10GBase-T would include data center connections, but it would also work in aggregation points in wiring closets.

But don’t hold your breath for products just yet. The group estimates that a standard won’t be finalized for another two-and-a-half years.