BT sounds death knell for ISDN

BT is to dump consumer ISDN services later this year, as users increasingly connect over DSL broadband, reports the BBC.

Ofcom recently declared that over half the UK adult population had broadband in their homes, but many still like ISDN (Integrated Services Digital Network) as it offers guaranteed bandwidth both to send and receive data.

The base BT ISDN rate is 64kbps and with the established BT Home Highway product users can double up two lines to get 128kbps in both directions.

ISDN is popular among many home workers and small businesses as it is an uncontended service guaranteeing these access speeds in both directions.

With broadband, users may get much higher top rate speeds but they cannot guarantee a connection if the amount of IP internet traffic gets too high.

The upstream sending speed of ADSL broadband is also far slower than the downstream access speed. While SDSL provides the same speed in both directions, BT and other telcos have limited SDSL networks.

Broadcasters in particular like ISDN services as the speed provided is ideally suited for radio broadcasts and provides guaranteed bandwidth ring fenced from other users.

BT doesn’t plan to axe ISDN for businesses, but if it did it, broadcasters would see their radio interviewers have to contend with other internet traffic, meaning delayed and jittery conversations.

Companies also use ISDN as a back-up data pipe if their broadband goes down - an increasing problem as more and more users sign up to high bandwidth broadband.

Related article: Over half of households have broadband

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