Naked DSL extends broadband reach

Several of Australia's largest internet service providers are using the new naked DSL style of broadband to extend the reach of their services and eliminate customer black spots.

ADSL, by far Australia's most popular form of broadband, has historically been sold with a bundled analog telephone service. However, Internode product manager Jim Kellett said this bundling limited the distance from telephone exchanges at which customers could access broadband, to around four kilometres.

But with the advent of so-called naked DSL, where ADSL is sold without an attached voice line, ISPs like Internode and iiNet are starting to push the limits out to up to seven kilometres away from exchanges.

Internode has so far only been offering naked DSL using Optus' network, which maintains an inactive voice line connection, but will in the next couple of months commence using its own exchange hardware in some areas, which can facilitate naked DSL without any voice service at all.

"There's a lot of people who will be getting broadband who couldn't before," Kellett told ZDNet.com.au.

The company started a trial in November with 120 people in South Australia where it ran services for distances up to seven and a half kilometres from the exchange. "The trial exposed various wrinkles in the activation and separation processes," Kellett said.

One such problem was that the normal way to test a line fault was to check for a dial tone on the line. However, the Internode DSLAMs (network hardware in exchanges) didn't have a dial tone at all, precluding this fairly simple test. Instead, the checking was carried out from the DSLAM itself to see if a line was dead.

Currently the company is getting its internal services in order, and ordering the unbundled local loop service from Telstra which allows naked DSL, Kellett said, adding that it had not yet been decided if all the exchanges across the country would be turned on at the same time: "We may restrict it to Adelaide and Melbourne in the first two months. The sheer volume of calls will be hard to handle."

Kellett believes customer take-up will be good. The company has carried out a study to find out the number of people living four kilometres from an exchange, getting an almost six-figure answer. "We were quite staggered by the potential number of customers," Kellett said.

iiNet chief technology officer Greg Bader said his company was already offering naked DSL on its own equipment, allowing the same distances to be achieved as Internode. "We've had some customers working at six to seven kilometres. Some of them get a fantastic service," he said.

However, these people are not a focus of iiNet's, he said, adding that although there are some who can't be served under the line sharing service (a predecessor to ULL), they could instead be served by unbundled local loop, but he didn't think the numbers were large.

There are other causes for black spots than distance, he said. "It's not going to solve every one." There have been cases, he continued, where up to 5Mbps has been achieved at seven kilometres on one line, but only 512Kbps at 500 metres on another line.