BT acts to combat broadband slowdown

BT Wholesale wants users to tweak their settings in an attempt to help keep their broadband speeds up

BT has begun testing a piece of software that could mean faster surfing for ADSL users, amid concerns that the boom in broadband take-up is impacting on connection speeds.

The application will change the size of the data packets sent by an ADSL user, setting it to a level that should ensure more efficient transmission of traffic across BT's network.

The pilot trial for this software -- which is known both as a "broadband network optimiser application" and a "maximum transmission unit (MTU) performance tweaker" -- was launched last week and involves BTopenworld and Zen Internet.

If successful, it is likely to be rapidly rolled out to all the ISPs who resell BT's wholesale ADSL products.

BT is taking this action amid concern that ADSL connection speeds are falling as more people sign up for broadband. This is because ADSL is a contended service - 500kbps bandwidth is shared between up to 50 consumers, or 20 business customers.

Given the bursty nature of Internet surfing -- where users are only sending and receiving data for a small proportion of their time online -- users should still be able to enjoy fast surfing even if they are sharing the available bandwidth with many other customers.

Some ISPs, though, have detected that actual speeds are falling, and they are attributing this to the recent surge in broadband take-up.

MTU performance tweakers have been in existence for some time, and can be freely downloaded from the Internet. They help users to change network settings in the Windows Registry to optimise performance for cable modems or xDSL, depending what kind of connection is used.

The software used in the BT trial sets the packet size to 1458 bytes, which is generally recognised as the optimum setting for an ADSL connection. At other settings, some packets have to be split before they are sent over BT's IP network, and then reassembled. This fragmentation requires the various parts of the network to perform more work, effectively slowing it down.

Changing these network settings is a non-trivial operation, which is why BT is turning to software that will make the necessary changes automatically. These changes will not give users more bandwidth, but by giving them a more efficient connection, it is hoped that actual speeds will increase, or at least not fall further.

Zen Internet -- which has said some of its customers have recently been experiencing slower connections than before -- believes the MTU tweaker could mean a better service for all broadband users.

"BT Wholesale's speedy development of this MTU tweaker is a great move. The more people that use this on their connection and find it to improve throughput the better for all users of ADSL -- the less fragmentation on the network, the better the service will be for everyone. We have already had good feedback from customers who have used the simple tool," Ian Buckley, marketing manager at Zen Internet, told ZDNet UK News.

"Although average throughput has been falling we are pleased that Zen customers have maintained good high averages and only a small minority of customers have been adversely affected by fragmentation in the network," Buckley added.

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