Internet
NTL offered broadband Internet access connections through cable. The service operates through SACMs (Stand-alone cable modems) and set-top boxes (STBs).
In NTL areas customers could also access a 512 kbit/s download-speed; and both NTL and Telewest offer dial-up Internet services on a pay-as-you-go basis, or at a fixed monthly fee of £14.99 for unlimited usage.
The broadband services did not have a bandwidth-cap or a fair-usage policy; this means that customers have unlimited usage and need pay no extra charges related to the amount of data downloaded. However NTL has admitted introducing traffic shaping.
NTL has started trialing 20 Mbit/s, and temporarily upgraded some 10 Mbit/s subscribers to this speed in October 2006. The 20 Mbit/s service reportedly supports 768 kbit/s upstream, though some users have reported seeing upstream speeds of 1 Mbit/s. Furthermore, NTL has started conducting trials of a 100Mbit broadband service on its cable network.
After trials in the Guildford area from summer 1999, NTL launched its original broadband services at the same time that NTL acquired the Cable business of Cable and Wireless (spring 2000). In the "original NTL" (also known as "Langley") areas, NTL has always supplied broadband services via DOCSIS cable-modems. In these areas the digital television set-top boxes used an incompatible standard, DAVIC.
The roll-out of broadband services in the ex-Cable and Wireless franchises started in mid 2001. Initially, NTL provided ex-Cable and Wireless subscribers with broadband through the set-top box (STB) also used for digital television services, adopting the rationale that subscribers could self-install. Initially, NTL supplied a "Self Install Kit" consisting of connecting cable, adapters and an install CD. Following demonstrated problems, NTL gradually introduced cable modems and phased out the self-install approach,
The Pace STBs proved highly problematic, exhibiting two major flaws. Firstly, large numbers of connections (for example, those with peer-to-peer (P2P) software) would cause the connection to slow down and eventually freeze the modem part of the STB (also required for interactive TV services, which suffered a similar effect when downloading). Customers in these circumstances had to re-boot the STB.
Secondly, the single processor and sharing the internal modem between television and broadband services made the television part of the box slow and unresponsive, for example making it extremely difficult to change channel using the remote. This became particularly evident when using the lower "Tiers of Service" such the 128 kbit/s downstream 64 kbit/s upstream, as the digital television set-top box without broadband service actually enjoyed a 256 kbit/s upstream.
Although capable of higher speeds (up to 4 Mbit/s), NTL did not make speeds higher than 1 Mbit/s available due to degradation of the DTV service.
NTL eventually replaced the Pace set-top boxes with Samsung models that used a dual-processor architecture, overcoming the shortcomings of the Pace, and capable of much better downstream performance. However, with the advent of higher "Tiers of Service" of 10 Mbit/s downstream and higher, plus the reducing cost of NTL's cable modems (supplied by Ambit Broadband) NTL now supplies all subscribers with cable modems.
A historical view of NTL cable modems appears online at the Chetnet site.
The NTL network runs through transparent proxy servers. Up to 15 server addresses host each area. These transparent proxy servers also override the user's hosts file and prevent manual DNS updates. This makes it easier for NTL to provide a more reliable connection as well as being able to monitor traffic requirements in each area. This also causes many problems for websites which record IP addresses to ban and/or track users. This means that if a website bans one offender, it bans everyone in the same area. Also, many on-line games automatically ban IP addresses with multiple usernames associated with them. Small-scale games do not cause too many problems, but when friends attempt to spread the game around, the system prevents everyone (including the original player) from using the game. On the other hand, advanced users can easily create a large number of illegitimate accounts on the aforementioned websites, allowing one user both to prevent all other users on the NTL network using the game, as well as to become untraceable.
Some of the STBs cannot support connection speeds above 1Mb. As many customers took up their connections before the system-wide upgrade from 1Mb to 2Mb basic rate, one commonly finds that people have paid for a 2Mb connection, whilst only having a 1Mb connection.
NTL has used MAC addresses to track and register customers to the NTL internet service. As NTL had not supported the use of routers, or Xbox on the minority Set Top Box based Broadband Internet service, users had to use a clone MAC address feature to connect to the Internet when using an STB. This has become a common problem for people wishing to connect their Xbox to the existing internet connection through a router or PC connected to their STB, if they fail to use the official registration process. (These comments do not apply to the majority (>90%) use of cable modems).
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