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Community Member

FXO to FXO connection problem

Trying to connect a PBX to a PSTN using 2 Cisco 1750 routers with VIC-2FXO-EUR cards.

If we ring the number attached to the PSTN then we get a dial-tone and we can key in digits. According to debug information this call gets routed to the other router attached to the PBX but it ends there.

If we try an outbound call by dialling 85 and thus connect to our router attached to the PBX we also get a dial tone but according to debug information none of the digits are being processed.

The connection between the router and PBX is a normal analogue telephone extension. Is this correct?

Can anyone suggest where the problem lies?



Re: FXO to FXO connection problem

Often times complex troubleshooting issues are best addressed in an interactive trouble-shooting session with one of our trained technical assistance engineers. While other forum users may be able to help, it’s often difficult to do so for this type of issue.

To utilize the resources at our Technical Assistance Center, please visit and to open a case with one of our TAC engineers, visit

If anyone else in the forum has some advice, please reply to this thread.

Thank you for posting.

Community Member

Re: FXO to FXO connection problem

Hi David,

Have your tried connection plar opx xxx (replacing xxx with the pots dial-peer on the pbx side) This way the incoming call will ring the port connected to the PBX and when the PBX answers, the FXO port will go off hook, thus completing the connection. I had the same issue and this took care of it.

Hope this helps, let me know if you need configs.



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