Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. And see here for current known issues.

New Member

VOIP configuration between FXO and FXS

Dear Sir,

We have implemented Voice over IP on our IPLC circuit between foreign office and India office.

Topology is such that our foreign office is having 1700 series router with wan card

(Wic-1T) and one two port FXO card connected to PBX for PSTN and local connsctivity.

India end we have a cisco 1700 router with wan card (Wic-1T) and two port FXS card.

Also we have many other branches connected to India office router on point to point lease links running data and analog voice (FXS).

We have configured voip using PLAR feature between foreign office FXO and india office FXS card.

1) Currently India office users via IPLC can communicate over voice and data with the foreign office (FXS to FXO).

2) Foreign office users can communicate with the india office users connected to IPLC link (FXO to FXS)

3) India office users can communicate voip with other branches in india (FXS to FXS)

We want to configure the foreign office router in such a way that foreign users are able to talk to remaining branches in india office (FXO to Many FXS cards)

Will putting voice route in the foreign office solve the purpose or we need to change the router voice config from PLAR mode to some other mode.

How the foreign office PBX will differentiate between point to point voice calls and other location voice calls.

Will the PBX/Router in foreign office be able to give dial tone to the FXO card.

Can we use the india end router as a voice switch for routing voice calls between foreign office and all the branches in india.

Any suggestions/config will be appreciated



Re: VOIP configuration between FXO and FXS

You will have to get rid of the plar configuration, because in plar you are essentially binding the port to a number. You will have to create multiple dial peers and have to wait for router to provide dialtone to the fxo port and then dial the appropriate number.

You cannot currently use the main site router to switch voice calls between offices.


New Member

Re: VOIP configuration between FXO and FXS


can i get sample config for the same.


New Member

Re: VOIP configuration between FXO and FXS

hi, can you send the "sh run config" to my email:


New Member

Re: VOIP configuration between FXO and FXS

hi, can you send me the sh run config to my email:


CreatePlease login to create content