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New Member

FXO port, never hangs up?

Ok, scenario is as follows:

3640, with 4 FX0 ports, conneted to a Nortel PBX in DC, and similar setup in San Ramon Cali. When making a call, via VoIP, I am using huntgroups on the PBX, wich seize the FX0 port and head out over IP to connect to the other office.

Now, here is the wierd part. Whether or not I am using a hunt group, or only have one extension set up, when I hang up the handset, the connection between the PBX and the CISCO 3640 never releases. Don't know why. I have to physically log into the box, and administratively shutdown the port and bring the port back online.

Can anyone help, or point to why this is happening?


Re: FXO port, never hangs up?

The problem you have is the router has no indication that the FXO ports are no longer required. You could try adding the supervisory command to the ports and getting the Nortel maintainer to set the analogue extension ports to deliver a break signal on disconnect.

What router are the FXO ports on, if you do not use the plar-opx command for an ios router then you will also find that if you ring a phone that does not answer and the caller hangs up, then the phone keeps on ringing and the port is locked in a busy state. I've not found a way to avoid this on a VG200

New Member

Re: FXO port, never hangs up?


right now your dialer seting is ground

make it loopback ,

it should work



Cisco Employee

Re: FXO port, never hangs up?

Also, if you have 4 FXO ports on the router in DC and 4 FXS ports on the router in San Ramon and you want a one-to-one mapping, you could use connection trunk instead. A good example can be found at:

Note that the example is using e&m-wink-start channels on a T1 but the concept is the same as far as setting up the voice-ports and dial-peers. Note that this will only work if one router has FXS ports and the other has FXO ports.

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