Heavy users who have been hammering their connection thoughout the day will have their speeds cut to 5Mbits between 4:00pm and midnight, after which the speed is reset.

For the vast majority of customers, probably in excess of 95%, ntl:telewest expect a more consistent upload and download speeds. Conversely, this indicates up to 5% of customers will see their speeds constrained.

The ntl:telewest reasoning is that some 10% of users take up to 70% of the network capacity. The trial is supposed to minimise the effects from those customers who are consistently downloading large files which affects others from enjoying a good broadband service.

Ntl:telewest believe this policy is justified and permitted according to clause 4.3 of their Terms & Conditions:

We reserve the right to monitor and control data volume and/or types of traffic transmitted via the Interactive Services and/or Internet Services. In the event that you exceed the usage allowances applicable to your Internet Services as detailed in the User Policy, we reserve the right (at our sole discretion) to reduce, suspend or terminate your Internet Services. During any time of reduction or suspension, you will remain liable for the payment of your original level of Internet Services charge. We also reserve the right (at our sole discretion) to re-grade your Internet Services to a different speed and/or usage allowance at the appropriate charge.

The old issues of the bad days of capping policies rear their head. ntl:telewest suggest that affected users will only be those who breach the User Policy.At what point does a customer’s usage become unacceptable? There is no guidance now on offer in the Acceptable Use Policy which promotes that services are now unlimited use.

We understand that ntl:telewest will deny the customer is affected unless they directly ask if they are being traffic shaped.

Cable Forum Users are discussing this matter here