Tuesday

Tuesday 18/03/2003BT announces Midband, which sounds like a talent contest for Birmingham pop groups but is really the answer for people out of range of broadband. Or so we thought: on inspection, the promised permanently on system with more range and less speed than DSL turns out to be ISDN.

Tuesday 18/03/2003
BT announces Midband, which sounds like a talent contest for Birmingham pop groups but is really the answer for people out of range of broadband. Or so we thought: on inspection, the promised permanently on system with more range and less speed than DSL turns out to be ISDN. Flat-rate ISDN, to be sure, but capped and not that different from Home Highway. It turns out, says head honcho Pierre Danon -- does anyone else hear a female voice coo "Oooooh, Danon!" whenever his name comes up? -- that they want to do permanently on email but it's very hard, even for the big brains at BT. Which is odd, as everyone else in the world manages it -- as did BT around ten years ago. Most people know that ISDN is a 128Kbps link, made out of two independent 64K digital telephone connections. In ISDN parlance, these are called B channels (for Bearer, would you believe), and like any telephone line they're only connected when a call's in progress. However, there's a third or D channel (for data) which is always connected. It's only 16Kbps, but that's OK -- enough to send "Email's here!" messages and trigger a B channel call if it gets congested. ISDN D channels have been always-on forever: it's been in the spec since the standard launched 20 years ago. Which means that BT has had an always-on nationwide network for at least a decade, but it's tried very hard to hide the fact from the outside world. Inside, there have been several attempts to commercialise the system -- originally with X-25 protocols, one of IP's forerunners, but more recently as part of BT's Internet thrust. Every time, one is led to believe, the technical side proved tractable but the idea fell apart because nobody could agree how to do the billing. As per usual, bits of BT saw D channel networking as competition, and BT's instincts to sell anything new as an expensive, premium service didn't do too well with the marketeers. There's no reason to think that the same reasons aren't behind the emasculation of Midband -- especially since there's been an industry standard, AO/DI, for D channel networking since 1998. But the chances of the company being taken to task for not developing the market properly are minimal. Will Oftel's transformation to Ofcom give it any teeth, or the taste for using them? Sigh.