Ben Merrills
2004-Sep-29 00:40 UTC
[Asterisk-Users] PRI D-channel signalling error? "Ring requestedonchannel 0/1 a lready in use on span 1. Hanging up owner."
This was happening to me a week or so ago. The problem came from the fact calls were being hungup on, however, asterisk (or zaptel/libpri) said not. The system thought the channels were still open, and so collisions started to occure. I recompiled zaptel and libpri and installed them again (from cvs). Hope this might help you, Ben -----Original Message----- From: asterisk-users-bounces@lists.digium.com [mailto:asterisk-users-bounces@lists.digium.com] On Behalf Of Peter Svensson Sent: 29 September 2004 08:23 To: dboyd@fullmoonsoft.com; Asterisk Users Mailing List - Non-Commercial Discussion Subject: RE: [Asterisk-Users] PRI D-channel signalling error? "Ring requestedonchannel 0/1 a lready in use on span 1. Hanging up owner." On Tue, 28 Sep 2004, David Boyd wrote:> > -----Original Message----- > > From: asterisk-users-bounces@lists.digium.com > > > > Can anyone shed some light on "Ring requested on channel 0/1 already> > in use on span 1. Hanging up owner."? This is happening two or > > three times a day on a span with about 500-600 calls per day. The > > remote device is a PBX, connected by a crossover cable and protocol > > is DMS-100. > > Sounds like it could be glare, is the span two way?The q931 specification (5.7) seems to say that there can be a conflict of channels, if both the cpe and the net selects the same B channel for one call each at the same time. I guess this can be prevented if the cpe allows the net to select the B channel for the outgoing calls (Any Channel Acceptable). Barring that, a contention can occur and is handled by the cpe side clearing its still unconnected call. The cpe side could retry the call on a different B channel at that point.>From q very quick look at chan_zap and the messages from a pri intensedebug it seems that Asterisk selects a B channel and requests that particular channel from the net. For the normal isdn configuration (the net hunts from low channels, the cpe hunts from high channels) there should rarely be a collision unless the trunk is close to saturation, in which case congestion _is_ the correct result. Peter _______________________________________________ Asterisk-Users mailing list Asterisk-Users@lists.digium.com http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users