[asterisk-users] Sangoma and BT single lines

[Gordon Henderson]

On Mon, 6 Apr 2009, Ed W wrote:

> Hi, got a Sangoma A200 with a bunch of extension cards and having real
> problems getting it to deal with a normal single BT line
>
> Symptoms are that incoming calls are fine.  Outgoing calls ring the far
> end, BUT asterisk never sees that the call is answered (ie no message in
> the logs files saying so), as a result the remove end can hear the PBX
> side talking, but there is no audio back from the remote side to us.
> When we hangup the log files show messages thave suggest it thinks the
> line is still ringing

I've not used Sangoma analogue cards - just digium and OpenVox.

Never really had an issue though. For analogue lines, Asterisk assumes the 
line is "open" or answered as soon as the last DTMF digit is sent down the 
line - it's got no real way of knowing when the far-end answers. (At least 
with normal BT lines I've used)

So I'd be wondering if there isn't something else going on? One way audio 
is often NAT issues, but it's working with incoming calls for you, but not 
outgoing - which seems odd..

> Comparing with another line which works fine (this is a BT multi-line
> system with what they call "PBX signalling" on it) I see that as soon as
> the remote end answers then asterisk gets a log message stating the same
> and audio is fine on this line

I've never asked BT for anything special on lines - I wasn't aware they 
could do much on analogue lines... (I think you can tell them the lines 
are for PBX use, but I've never had any issues)

> Have now spent nearly 4 months trying to get the signalling sorted on
> this line.  Most recently we requested "dual signalling" on the line -
> the end result is now that outbound calls work and asterisk reports that
> the phone answers, however, when you hangup the call then asterisk
> obviously gets a bunch of extra line reversals and things there is an
> immediate incoming call on the back of that outgoing call...
>
> Please - any suggestions on how to configure a Sangoma card for use with
> a normal BT single line?

Bit of a long-shot, but try an OpenVox card as a cheap test of alternative 
technology?

Gordon