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FXO port disconnect problem

Just would to ask some ideas what is the possible problem having a setup of FXO to FXS connection disconnect problem.

The setup uses Cisco 3640 at the headoffice with FXO 2 voice ports connected to PABX and Cisco 1750-4V at the remote with 2 FXS ports. These 2 FXO ports are configured as plar. After several calls are being made to and from this port 0,it creates a problem. The problem encountered is..even if its not being used it will give busy tone eventhough its not being used. As displayed in the "show voice port summary" the port 0 of Cisco 3640 displayed up up idle on-hook which I believe the normal status if not in used is up dormant idle on-hook.But at the remote site,that counterpart port number is already dormant.

With this problem, the only way it will go back to dormant state is to reboot the Cisco 3640 Router.And then, that port 0 will be operational again for 20 hours and same problem will occur and tried rebooting again...for 4 times of rebooting already.I have noticed that problem occurs every after 20 hours of operation.

The connection or that local connected to that port 0 of Cisco 3640 had tried transferring to port 1 and is operating normally.

What is the cause of the problem? and what can be done to solve this problem?

Looking forward for your great ideas.




Re: FXO port disconnect problem

Sounds like maybe a software bug. You can use the software bug toolkit to check your version against or call tac for help.

Community Member

Re: FXO port disconnect problem

Okay, thanks for your great idea. Actually, we're using the latest version. 12.2 and i think this might be the problem.


Community Member

Re: FXO port disconnect problem

Hi Vivira,

Please note the type of "disconnect" that you have selected for the FXO. PBXs either use "tone disconnect" or "power interrupt" to tear down the call. The setting you have for FXO should match that of the PBX or key system.

Hope this helps.

Marto Asadoorian

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