Hi Jim, We had this exact problem with our system for several years. A call would come in with no caller ID and when we answered nobody would be there. On the Asterisk console would be the "Got event 17 (Polarity Reversal)" message.
We spent hours and hours on this. Our carrier was AT&T (SBC). I spoke with their tech support several times and spoke with many phone guys. Nobody could solve it. We moved our office to a new location and are now using Comcast VOIP lines into the TDM card and the problem is gone now. It had to be something with the POTS lines we were getting from AT&T. Another interesting thing is that we didn't get the calls all the time but when we did get them they were ALWAYS on the hour or half-hour. Thanks, Dan -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Jim Duda Sent: Friday, October 10, 2008 11:57 AM To: asterisk-users@lists.digium.com Subject: [asterisk-users] Got event 17 (Polarity Reversal)... Can anyone tell me what this message means? Got event 17 (Polarity Reversal)... I'm running DAHDI 2.0 with a TDM401 card. Asterisk version 1.6.0. It appears that I get this Polarity Reversal each time an inbound call hangs up. This results in another ring, but no one is there. It appears as an unknown caller, but I believe its a phantom. Thanks, Jim [Oct 10 12:47:54] NOTICE[6669]: chan_dahdi.c:7379 mwi_thread: Got event 17 (Polarity Reversal)... Passing along to ss_thread -- Starting simple switch on 'DAHDI/4-1' [Oct 10 12:47:55] NOTICE[6671]: chan_dahdi.c:7114 ss_thread: Got event 4 (Alarm)... [Oct 10 12:47:55] NOTICE[6671]: chan_dahdi.c:7114 ss_thread: Got event 17 (Polarity Reversal)... [Oct 10 12:47:56] NOTICE[6671]: chan_dahdi.c:7114 ss_thread: Got event 5 (No more alarm)... -- Executing [EMAIL PROTECTED]:1] Goto("DAHDI/4-1", "incoming-dial,s,1") in new stack _______________________________________________ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users _______________________________________________ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
