Steer clear of category 6 cabling, says BT

Debate rages as to which cabling firms need for the latest high-speed technologies, Antony Savvas reports.

Debate rages as to which cabling firms need for the latest high-speed technologies, Antony Savvas reports.

Debate rages as to which cabling firms need for the latest high-speed technologies, Antony Savvas reports

Category 6 cabling is simply not necessary to run high-speed Gigabit Ethernet, says BT.

The UK's biggest cabling installer, has recommended that businesses should install category 5 enhanced (category 5e) copper cabling for broadband services and steer clear of unproven category 6 standards.

But whether companies need to upgrade from category 5 to category 5e for high-speed technologies like Gigabit Ethernet, is still open to question.

When Gigabit Ethernet appeared as an option for companies to deliver high-speeds to the desktop using traditional twisted pair copper cabling, a debate started to rage as to whether the existing category 5 cabling in most buildings could cope.

BT cabling product manager Kevin Sollis says, "During the last two years BT has installed category 5e cabling that is guaranteed to support Gigabit Ethernet, but category 6 is simply not necessary for Gigabit Ethernet.

"Even after more than a year, the standard for category 6 is still very much unresolved. Test methods for connecting hardware are still under development, potentially leading to sub-category 6 performance with hardware supplied by different manufacturers."

And Sollis claims companies considering combining both category 5e and early versions of category 6 will suffer lower performances than category 5e. Sollis adds that any companies wanting higher speeds than Gigabit Ethernet should opt for expensive fibre instead.

What it comes down to is the connection distances for the traffic, but the suppliers have seized on a potentially lucrative market created by companies' fears that their networks won't be future-proofed for faster technologies in the pipeline. Suppliers, led by Lucent, have already formed the 10 Gigabit Ethernet Alliance, which could create even greater anxiety amongst network managers, but standards body the IEEE, isn't in the pocket of the suppliers.

The IEEE maintains that 90% of installed copper wire (category 5) should be able to cope with Gigabit Ethernet over copper providing the connection distances are less than 100m. But this has not stopped some large companies installing enhanced copper wiring when upgrading existing networks or installing new ones.

NatWest has chosen to install a mixture of category 5e and the draft standard category 6 and will use Lucent Gigaspeed untwisted pair throughout its banking network. NatWest has signed a three year contract with WG&R Communications, which will take responsibility for the technical decisions.

NatWest group purchasing manager Mark Marney says this method of networking has been chosen to ensure that the banking giant has enough bandwidth to take advantage of Gigabit Ethernet and future networking technologies. The fact that WG&R is responsible for the technical decisions and the implementation of the project ties in with the advice of the IEEE.

The IEEE advises companies not to rely solely on supplier advice, but to test their networks themselves or hire a third party to see if their networks can avoid potential signal interference or echo. The BT advice on installing category 5e is supported by BT rival BICC Brand-Rex, which says that the multi-pair, bi-directional transmission technique used by Gigabit Ethernet, and new parameters such as Far End Cross Talk and Return Loss, requires category 5e.

BICC maintains that ordinary "barely compliant" category 5 systems with no "headroom" will find it difficult to cope, and that signals being sent down different sections of the twisted pair copper risk being delayed if enhanced category 5 is not used.

This advice has been taken up by Elf petrol stations across the UK.

BT has signed a £3.4m contract with Elf to install category 5e and new telephone systems to link its 350 petrol stations. This will include ISDN and videoconferencing connectivity.

Elf has chosen to effectively future-proof its network, but companies on tighter budgets, or who do not need anything as fancy as bandwidth-hungry videoconferencing, should perhaps take heed of the adage, "it's tougher to look than to leap".

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