BT Plans Move To IP Telephony, Starting Next Year

pure_equanimity writes "The BBC have published an article saying that BT are planning to migrate from a PSTN to an IP network, a move to cost 3bn. They say that broadband will become ubiquitous, with customers having the ability to plug any device in to get access. They also say that current cheap broadband products will more than likely not be viable in five years time. They plan to start rolling out in 2006, and cover the vast majority of customers by 2009."

Comments

Re:So what numbers will we use

[ZombieEngineer]

When you go to IPv6, it makes it nigh impossible for sales people to cold call your unlisted IP address.

ZombieEngineer

Re:As usual...

[Xrikcus]

But it's a very different thing trying to use VOIP over the internet itself, general public data networks with little by way of service guarantees, and converting a managed telecom backbone network to use IP.

Re:PSTN?

[Alioth]

Actually, PSTN does stand for Public Switched Telephone Network - the public bit meaning not private (as in PABX - Private Automatic Branch eXchange).

Packet switching on telephone networks is a relatively new thing (compared to the history of automatic telephone switching). Until 20 years ago, most telephone switching was still done by electromechanical machines (google for Strowger Telephone Exchange) - huge rooms full of physical switches (uniselectors, bidirectional selectors) and relays which moved and clattered as subscribers dialed telephone numbers; the tones (such as ringing, number unobtainable, engaged etc) generated by a motor-driven machine. If you go to the London Science Museum, they have part of one of these exchanges you can play with.
Trunk calls were routed using analogue frequency division multiplexing rather than packet switching. Signalling between mechanical telephone exchanges was done at voice frequencies (for example, the famous 2600Hz tone - in Britain, the frequency was different and it was known as 2VF - if you listen to some Radio 4 radio plays you'll find the sound engineers still like inserting the 'pip' sound when someone answers a call which you heard when the 2VF signalling wasn't quite fully supressed from reaching the subscriber's phone. These 'pip' sounds probably disappeared from the public network 20 years ago but the sound engys at the BBC seem to like them).