[VoIP] Drop out on answer on Strowger switch.

[Ian Jolly]

Hi All

We have an Asterisk with a Zapmicro (version of the Digium TDM400) with one FXS and an FXO connected to a former British Post Office UAX13 Strowger exchange. 

The FXO is connected direct to its own first group selector.  

On dialling a call into the Strowger switch, the call rings out but 90% of the time, as soon as the call is answered the call drops out.  At the point that the call is answered, the Strowger switch reverses the polarity of the line to the FXO.

On the other 10% of the calls, speech is possible for up to a minute after answering then the call drops out without warning.

We have the following in zapata.conf

answeronpolarityswitch=yes
cleardownonpolarityswitch=no

but to no effect   :-((

Anyone any ideas?

Ian J