UC520 upgrade

Unanswered Question
Dec 9th, 2008


I have a production router UC520 with IOS version uc500-advipservicesk9-mz.124-XW4. The router has 4 FXO ports but 20% of the calls comming on this ports from PSTN have one way audio , other 80% are ok. After debug I could not find reason for this to happen , incoming rtp traffic just stops .. Now I decided to try upgrade the IOS to uc500-advipservicesk9-mz.124-22.T , but couldn't find exact info is it possible to face some incompatibillity btween newer IOS and the running CUCME . I do not want to change the Call manager express because of custom scripts and configs it is running..


I have this problem too.
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Nicholas Matthews Fri, 12/12/2008 - 12:01

The UC520 has a number of files that it upgrades with in a package because it's slightly different than a normal gateway. One of the largest differences is the CUE version that it runs.

There are a lot of suggested compatibility versions, but the compatibility is much looser than most people expect.

If you're having intermittent one-way audio I would make sure that you don't have intermittent routing / switching errors. These are the most common problems.

You can use a 'show call active voice brief' to check the incoming packets for a voip call to see if you are receiving them.

It is also possible that there are bad DSPs on certain channels that have ceased to work. Or possibly bad FXO ports.

dan hale Tue, 10/26/2010 - 23:55

Hi, Did you ever resolve this issue? I'm having a very similar problem and debating on a code upgrade hoping that it will fix the issue.



Paolo Bevilacqua Wed, 10/27/2010 - 06:50

Two years old post, it's unlikely the OP is still monitoring.

However about code updates, there is no point in debating, they are a must. Have you ever looked at the list of bugs fixed in subsequent releases ?


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