Re: [Hampshire] Primary Rate ISDN (plus a bit of Asterisk)

James Courtier-Dutton <james.dutton@???> wrote:
> ISDN PRI can be very difficult to set up. This
> is mainly due to * being all set up for the US
> ISDN, and not well tested with the UK ISDN. I
> would therefore recommend only using the ISDN
> PRI cards that * recommends.

Thanks, James. I'll check voip-info.org and the
mailing lists to see what people have successfully
used.

> But, if you get the line up, without any alarms
> (I.e. Layer 2, line not syncing up or not
> keeping sync) then the Layer 3 (The actually
> ISDN calls) is easy. You will not get any of
> the problems with lack of answer detect etc. as
> ISDN gives explicit out of band signaling for
> that.

That will be good!

> You will want a number of different numbers
> assigned to the ISDN30 line. These numbers can
> then be used for DDI. Any of the 30 ISDN
> channels can be used to receive or send on any
> of the numbers.

That's something I need to talk to BT (and other
suppliers) about. The projects don't really need
DDI, just two public numbers, one for each. I'll
have to find out if I need DDI for _that_.

There's also some involved requirements for
keeping existing numbers. One project has an 0800
number that needs to be transferred, and the other
would like to move a local number from an analogue
line.

> I used to work for a telco equipment supplier,
> so I do have extensive knowledge of ISDN if you
> have any further, or more detailed questions.

Thanks! I have no doubt I will, when I get into
the nitty gritty.

Nick.

--
Nick Chalk ................. once a Radio Designer
Confidence is failing to understand the problem.