Hi,<br><br>I've been experiencing trouble with my DAHDI channels for some time and have finally decided to try and resolve the issue.<br><br>Essentially, the problem I am having is that when a call comes in, and my DAHDI phones therefore ring, Asterisk thinks that one of the handsets has picked up to answer the incoming call - whereas in actual fact it is still on hook. The call then gets instantly dropped (the phone is on-hook, after all), and the caller has to redial.<br>
<br>Sample log (this is an incoming call from SIP/5555, that was "phantom answered" by DAHDI/7. There is no time delay between the 'answered' line and the 'hungup' line):<br><br> -- DAHDI/5-1 is ringing<br>
-- DAHDI/3-1 is ringing<br> -- DAHDI/7-1 is ringing<br> -- DAHDI/2-1 is ringing<br> -- DAHDI/4-1 is ringing<br> -- DAHDI/6-1 is ringing<br> -- DAHDI/7-1 answered SIP/5555-0000011f<br> -- Hanging up on 'DAHDI/6-1'<br>
-- Hungup 'DAHDI/6-1'<br> -- Hanging up on 'DAHDI/4-1'<br> -- Hungup 'DAHDI/4-1'<br> -- Hanging up on 'DAHDI/2-1'<br> -- Hungup 'DAHDI/2-1'<br> -- Hanging up on 'DAHDI/5-1'<br>
-- Hungup 'DAHDI/5-1'<br> -- Hanging up on 'DAHDI/3-1'<br> -- Hungup 'DAHDI/3-1'<br> -- Hanging up on 'DAHDI/1-1'<br> -- Hungup 'DAHDI/1-1'<br> -- Hanging up on 'DAHDI/7-1'<br>
-- Hungup 'DAHDI/7-1'<br> == Spawn extension (macro-stdexten, s, 3) exited non-zero on 'SIP/5555-0000011f'<br><br>I'm using a PhonicEQ E100P card in my Asterisk box, paired with a Zhone Zplex 10 channel bank - this has worked perfectly for years in all other respects.<br>
<br>My first thought was that it was a hardware issue, related to short line length perhaps (cable runs are over Cat5 structured cabling, anywhere from 5-30m long), or possibly due to my use of "PABX Master" phone adapters with ring capacitors, instead of plain adapters. (This is probably UK specific - the adapters look like this: <a href="http://www.cablecity.co.uk/product_info.php?products_id=439">http://www.cablecity.co.uk/product_info.php?products_id=439</a> )<br>
<br>However I did swap out the PABX Master adapters for plain ones, and this made no difference at all. I haven't got much control over the cable length, either. The issue seems to manifest itself mostly on a couple of channels (5 and 7), which have quite different cable lengths - and I did also try a different telephone handset on channel 5 (this has the shortest cable length). No difference.<br>
<br>My next angle of attack was the software - I dug around in the dahdi source code to try and find timeouts to adjust, so that it wouldn't be quite so quick to think that I had picked up the phone. However I didn't have any luck with that, either. There is a 'debounce' parameter which is great in theory, but only worked when I hung up the phone - it had no impact on picking it up in the first place.<br>
<br>So I'm throwing the question open to the amassed wisdom of [asterisk-users]. Can anybody perhaps point me in the right direction of what I can try next?<br><br>Thank you!<br><br>Jonathan<br>-- <br>"If we knew what it was we were doing, it would not be called research, would it?"<br>
- Albert Einstein<br><br><br>Software versions:<br>dahdi-linux-2.3.0.1<br>Asterisk SVN-trunk-r280559M (built on 2010-07-30 00:09:55 UTC)<br><br>Config snippets:<br><br>/etc/asterisk/chan_dahdi.conf:<br>[channels]<br>
; Have tried this, but it only affects going ON hook, not going OFF hook<br>; debounce=1000<br>rxgain=0.0<br>txgain=0.0<br>group=1<br>callgroup=1<br>pickupgroup=1<br>immediate=no<br>signalling=auto<br>--- most of the channels look like this---<br>
mailbox=****<br>callerid=******* <****><br>context=******<br>accountcode=***<br>callgroup=1<br>pickupgroup=1,2<br>channel=>5<br><br>/etc/dahdi/system.conf:<br>loadzone=uk<br>loadzone = us<br>defaultzone=uk<br># T1 interface with channel bank<br>
span=1,0,0,esf,b8zs<br>fxoks=1-24<br># T100p plugged into BT line<br>fxsks=25<br># 2010-08-18 No echo canceller is now loaded by default<br>echocanceller=mg2,1-25<br>