[cisco-voip] FXO disconnect problem - telco side?

[Tom Storey]

Hi all,

Im having an issue with a 1760 setup I have.

I have an analogue phone connected to an FXS port, and the PSTN  
connected to an FXO port.

When I make a call in from the PSTN to the Cisco, the analogue phone  
rings, I answer, and then if I hang up the analogue phone, the FXS and  
FXO appear to go on-hook, but the telco still believes the call is  
active - that is until 21 seconds later when the telco realises there  
is nothing going on (silence detection?), and terminates the call.

I can verify that the telco still believes the call is active because  
if I call the PSTN line with a second phone after hanging up the  
analogue phone connected to the FXS port, I hear call waiting tones  
from the phone that is still connected from the PSTN.

Have played a bit on my own, and also had a friend look at my config,  
but we havnt been able to figure it out as yet.

Weve played around with disconnect tones, but Im not sure if the Cisco  
will actually generate disconnect tones towards the telco to tell them  
to hang up, or if it will only detect them from the telco.

Does anyone have any suggestions for things I can try to tell the FXO  
to hang up in an alternative way? Im guessing the way it hangs up is  
not a way the telco considers it to be a hang up, and only terminates  
once silence detection determines there is nothing happening on the  
line any more. Thats an assumption, but seems to be correct at this  
stage.

Im in Australia, and the telco is Telstra - if that helps any more. :-)

Can provide configs etc is neccessary, but its nothing special.

IOS is c1700-ipvoicek9-mz.124-15.T5.bin.

Cheers,
Tom