Solved: random incoming FXO calls do not connect

mark · ‎03-13-2012

Hello,

I have a UC520 with 4 anolog lines. It seems that calls at random will not connect. We get about 50 calls a day and when we pick up the phone the call does not connect, then the caller calls back it it connects. I don't know if it is specific to one port, we recently moved offices and it was doing the same thing at the old office. So it is not a line because we have new lines to the system. Some calls work fine and others do not connect the call. Is there any commands that I can add to the fxo ports to get this working. I just have a standard config on the ports, see below. Any help is much appreciated.

voice-port 0/1/0

connection plar opx 206

caller-id enable

!

voice-port 0/1/1

connection plar opx 206

caller-id enable

!

voice-port 0/1/2

connection plar opx 206

caller-id enable

!

voice-port 0/1/3

connection plar opx 206

caller-id enable

Alexander Maroukian · ‎03-14-2012

Hi Mark,

You can also try with "no battery-reversal" or "battery-reversal" under all of the FXO ports configuration. If you are using now battery reversal change it to the other. You may not see battery-reversal because it is default setting for the voice port you will see only no battery-reversal.

Also you can take a look at this document:

www.cisco.com/en/US/docs/ios/12_2t/12_2t2/feature/guide/ft_ansds.html

HTH,

Alex

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View solution in original post

David Trad · ‎03-13-2012

Hi Mark,

Can you please do a debug on some incoming calls, and just advise which ones worked and which ones didnt so I can gather the info from thed bugs much quicker.

The process:

ROUTER# term mon

ROUTER# deb vpm sig

You will see a fair bit of chatter on the screen when you do this, make sure your putty session is set to capture as many lines as possible, I like to set it to 200000 just to be on the safe side

Post your debug logs when done so they can be inspected.

Cheers,

David.

Cheers, David Trad. **When you rate a persons post, you are indicating a thank you or that it helped, but at the same time you are also helping to maintain the community spirit - You don't have to rate posts and you wont be looked down upon :) *

Alexander Maroukian · ‎03-14-2012

Hi Mark,

You can also try with "no battery-reversal" or "battery-reversal" under all of the FXO ports configuration. If you are using now battery reversal change it to the other. You may not see battery-reversal because it is default setting for the voice port you will see only no battery-reversal.

Also you can take a look at this document:

www.cisco.com/en/US/docs/ios/12_2t/12_2t2/feature/guide/ft_ansds.html

HTH,

Alex

*Please rate helpful posts

mark · ‎03-23-2012

The "no Battery-reversal" command did the trick. The system has no more mysterious hang ups.

Thank you,