Not able to answer inbound call on FXO port

[celticartifact]

The UC500 has been setup with Configuration Assistant and all works fine including SIP Trunks and Unity.

Inbound calls received on the FXO Port ring on the target phone but going off hook does not connect the call. The phone continues to ring.

Any ideas?

[irisrios]

What kind of signaling are you using for FXO? Is it Loop start or Ground Start?

[celticartifact]

Thanks for your reply. I have actually managed to identify the problem.

Finally I decided to test the cables which went through several connections.

Using a POT I traced back for dial tone and found that I needed to replace one of the cables in the link.

I had assumed the cables were okay---inbound calls were ringing at the target extension!!!

For the record here are more specifics of the fault symptoms:

Using a mobile place the call to the line terminating on the FXO port.

Ring tone on mobile

2-3 seconds elapses

Target extension rings

Off hook

Audible Ringing ceases on target extension, ringing persists on mobile.

3-4 seconds elapses

Audible ringing on target extension restarts even though still off-hook.

I haven't done the investigation yet but I speculate that perhaps the problem cable was a crossover cable??