On 12 Apr 2001, at 18:35, lester@... wrote:

> > ISDN isn't dialed, it's connected, same as DSL and Cable, it's
> > pretty much point to point to the CO and then from there, many phone
> > companies run everything that isn't already digital trhough an ADAC,
> > and along fibre anyway.
>
> European ISDN is dial on demand, permanent connections are available,
> but cost mega bucks. WHEN we get ADSL(DSL) we will have a permanent
> connection ( I'm promised that some time next year - if I am close
> enough to the exchang - but they can't test that until they install
> the head end! ). ADSL contention will then be the problem - currently
> packets are dropped ( or rather time out ) at peak times because there
> is insufficient capacity.

What I meant by connected, like DSL, is that you skip two ADACs and
the actual dialup process. Technically unless your running through a
company switch or PBX then even voice is point to point to the CO.

As for contention, phone companies really overbook their capacity,
but they can never be sure how much overbooking they can do. As long
as people think, that performance is crappy, and that it should be
crappy, then the companies will think everything is fine. However
when customers call and say that performance is the pits, then the
companies know that they need to increase the capacity. So maybe
they run another Fibre line from the CO to the Backbone.

It's the same with equipment, if your complaining that your
connection is up and down like the seat on the only toilet in a pub,
then they can find the problem, and maybe replace or repair the
equipment so that the problem goes away.

Paul



Paul Schmidt,
Tricat Technologies
Email: paul@...
Website: www.tricattechnologies.com