Ithink this below which from the Chetnet Knowledge Base wesite will answer all questions already raised in this thread.
Virgin Media 256 (from February / March 2008)
The 256 model will be yet again supplied to Customer specification by Ambit ( www.ambitbroadband.co.uk ). From the outside it is identical to the 255 model, but features a revised Broadcom chipset, the BCM3349KFBG
This modem is still in a black Ethernet only housing, and is still "Dual Mode", and will be deployed across the whole Virgin Media network, including the ex-Telewest platform.
Does support 10 and 20 Mbps Tier of Service, is capable of 40Mbps+
Note: this modem will not support the 50Mbps service that Virgin Media has announced for launch in late 2008.
please check this link for more NTL modem information
http://www.chetnet.co.uk/articles/in...x_v2&id=91&c=4