Hi there, I'm trying to set up a small asterisk box for our company, and am using a TDM400P with an FXO module in it for one of the external PSTN lines. I'm having problems getting Asterisk to detect the remote caller hangup; when a call is received, I get the following messages on the Asterisk console: Exception on 16, channel 2 Got event Polarity Reversal(17) on channel 2 (index 0) Dunno what to do with event 17 on channel 2 and another of these when the caller hangs up. As far as I can tell, the first could be an indication that caller id is present, although I am getting that through ok. Most of the information I can find seems to suggest that Asterisk is aware of 'Open Loop Disconnect' and the Asterisk Wiki page on Disconnect Supervision does seem to indicate that reversing the polarity is one way of doing Disconnect Supervision. While I go off and try to find the relevant bits of code, I thought I'd just post a query here to see if anyone can quickly point me at the approrpiate configuration settings etc. Many regards marty -- Marty Lee e: marty@upstart-training.co.uk Technical Director m: +44 7747 567 267 Upstart Training Ltd f: +44 871 433 8922 Scotland, UK w: http://www.upstart-training.co.uk