Show voice port summary for FXO

Unanswered Question
Aug 12th, 2011
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Hi everybody,

I am trying to know the meaning of show voice port summary. I got the following output from one router and I need to know why it is like this?

                                         IN       OUT


=============== == ============ ===== ==== ======== ======== ==

0/0/0           --  fxo-ls      up    down idle    off-hook y

0/0/1           --  fxo-ls      up    up       idle     off-hook y

0/0/2           --  fxo-ls      up    down idle     off-hook y

0/0/3           --  fxo-ls      up    down idle     off-hook y

As you can see the status of admin is down and I think the cause is shut down command under the port, but the problem is it is off-hook so how it is off-hook and its admin status down?

my customer told me that many times the ports are hanging and they are not able to send or receive calls.

Any body face this before?

Is there any case for Admin down rather than shut down command?

what is the most important thinks that I should look for if the ports are hanging?


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Overall Rating: 5 (2 ratings)
acampbell Fri, 08/12/2011 - 05:59
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I suggest that you use show logg and see when and why the voice ports changed status.

If the router notices there are many errors on the port it may shut down the port itself.

The fact that the port is showng OFF-HOOK infers to me that something externally is calling/seizing it.

Hpoe this helps


JustForVoice_2 Fri, 08/12/2011 - 06:09
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Thank you for your help.

I will try to check the logging soon. regarding:

"If the router notices there are many errors on the port it may shut down the port itself."

Errors like what? is it like Ethernet?

acampbell Fri, 08/12/2011 - 06:21
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No these will be a different type error - like voltage surges, short ccts etc

Voice ports like FXO are accross a 2 wire telephone line with Ground & -50V being supplied from the telephone exchange (central office)

You could try swapping the input cable with a working port provided the configs are the same. See if the problems follow the the port or the cable.

If the fault is proved to the cable then you need to know where the demark is so you can ask the service provider to investigate.

Hope this helps.


JustForVoice_2 Fri, 08/12/2011 - 06:40
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Can we say it is always related to physical issues?

I have one router in my lab and when I used the command:

show voice port 0/1/0



The Last Interface Down Failure Cause is Administrative Shutdown


do you know if there is a reference for failure causes? like here I used shut down command so I got Administrative Shutdown


JustForVoice_2 Sat, 08/13/2011 - 01:47
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I checked th logging and I found the following:

Interface Foreign Exchange Office 0/0/2, changed state to operational status down due to cable removal

but the cables are connected

kingwave602 Wed, 05/02/2012 - 01:16
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I have same problem, May I know did you slove this problem yet?


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