[ILUG] [OT] ISDN -- AO/DI supported?

[Padraig Brady]

> Justin Mason wrote:
> > 
> > Does anyone know which (if any) of the Irish ISPs support 
> this? It's the
> > "always-on" support for ISDN which uses the D channel for 
> low-bandwidth
> > signalling, so you can bring up the ISDN line when an 
> external user hits
> > your line.
> 
> Doeas that mean the D channel stays open at all times? If yes 
> then it's
> more than unlikely as PRA's come with only 2 D channels (per 30 B
> channels) and they're needed for call setup.
> 

D channel is always connected in both PRA and BRA.
Both PRA and BRA only have 1 D channel although
PRA has a BW of 64K as opposed to 16K for BRA.

The "always-on" feature makes use of the fact
that the D channel is always connected and
runs data services over it (in another virtual circuit).
This could be useful for sending/receiving email
for e.g.

Anyway special equipment is needed in the exchanges 
to support this and therefore is not simple to
implement.

I don't know of anyone in Ireland that supports the
service and have only heard of it in America.

For details see PC mag june 1998 (I think).

Padraig.