[Asterisk-Users] TDM400P / FXO / Polarity Reversal

[Marty Lee]

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 at 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