[asterisk-users] DAHDI - analogue, not seeing ringing (UK)

[Gordon Henderson]

So made my first forray into 1.4 and DAHDI and hit a problem. (Not 
convinced this is a DAHDI issue though...)

Testing an analogue line and asterisk sees the caller ID being passed, but 
then fails to detect ringing. A plain old analogue phone plugged in rings 
just fine.

Console output:

   == Starting post polarity CID detection on channel 4
     -- Starting simple switch on 'DAHDI/4-1'
[Jul 31 11:38:51] NOTICE[25970]: chan_dahdi.c:6671 ss_thread: CallerID number: 01364698123, name: (null), flags=4
[Jul 31 11:38:54] WARNING[25970]: chan_dahdi.c:6688 ss_thread: CID timed out waiting for ring. Exiting simple switch
     -- Hungup 'DAHDI/4-1'
   == Starting post polarity CID detection on channel 4
     -- Starting simple switch on 'DAHDI/4-1'
[Jul 31 11:39:18] WARNING[25971]: chan_dahdi.c:6688 ss_thread: CID timed out waiting for ring. Exiting simple switch
     -- Hungup 'DAHDI/4-1'

This system has 2 analogue lines on ports 4 and 3. The one on port 3 works 
fine - the 'fault' stays with the BT master socket, so swapping cables, 
ports on the asterisk side doesn't help.

It does sometimes work, which is annoying, but more offten doesn't work 
than it does.

Anyone seen this before?

The lines are a long way from the BT exchange if that's an issue - some 
4-5Km... (ADSL on the other line only gets 3Mb/sec)

Could it be a ringer voltage issue at the BT side of things?

I'm trying to replace an ancient BT Analogue PBX here - which obviously 
"just works" when plugged back in..

Any clues appreciated...

Gordon