Intermittent one-way audio problems with 7925.

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Sep 28th, 2009
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I have recently completed an multi-location install encompassing 5 locations with 5 separate UC devices. Each location has a UC500, a separate AIR-AP521, a 7925 IP Phone, and an assortment of other 79XX series IP Phones. At each location, I am having the problem described below with every 7925. All of the other wired IP phones work flawlessly.

The 7925 phone registers to the system and works fine without issues. Without warning, the 7925 will stop passing two-way audio. The callers can hear the person using the 7925, but the person on the 7925 is unable to hear anything on their end.

The problem can be recitified simply by pulling and re-inserting the battery. The phone will boot up and will work without issue for an undetermined amount of time. Sometimes days, sometimes just a matter of hours. Pulling and re-inserting the battery always fixes it.

The wireless configuration is pretty standard. We have separate SSIDs/VLANs for data and voice. We're using WPA-PSK to secure the WLANs.

The 7925 is always within 50 feet of the access point. These access points only service 1 7925 and normally service no data clients except for the occasional laptop they may be brought in.

All of the UCs are running the 7.1.1ea software pack. The 7925s using the phone loads included with the 7.1.1ea software pack.

I don't believe this to be a configuration problem, and I'm leaning more towards a firmware problem. I wasn't able to find anything in the Cisco bug tracking system. I thought I would ask the Cisco community at large to see if anyone else has had similar problems.

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Steven Smith Mon, 09/28/2009 - 15:24
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Is the UC520 wireless as well?  You could have a problem when roaming between the two which can take a while for audio to come back.  This shouldn't need a reboot of the phone to fix.  You could probably also reboot the phone instead of pulling the battery if there is something wrong in the firmware.

mega-byte Mon, 09/28/2009 - 15:28
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The UC520 is not wireless. I only have one wireless profile configured on the 7925 and its configured to only associate with the SSID of the wireless VLAN on the AP521. The AP521 is the only wireless access point within range that has the Voice SSID configured, so it shouldn't have anything to roam to.

I agree a reboot would probably also fix the problem, but understandably my customer doesn't want to have to do that.



Steven Smith Mon, 09/28/2009 - 15:43
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The reboot option was only intended as a way to not have to pull the battery out.  I meant in no way that this would be a workaround or any type of fix, I apologize if it came across this way.

I would recommend opening a TAC case.  They are going to be the best bet for troubleshooting these type of issues.

Steven Smith Tue, 09/29/2009 - 07:36
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I am not sure if this bug fixes both of your issues, but here is some information that I have found.

1-way audio due to no Networkdown event to SCCP when switch profiles

Looks like this is fixed in 1.3.2 and 1.3.3 firmware for the the 7925 phone.  Try upgrading to 1.3.3 and see if you have the problem.  Otherwise, you should probably open a TAC case.

Marcos Hernandez Mon, 09/28/2009 - 15:26
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I did a search on one way audio issues in the problem report database and the causes for one way audio on the 7925 are too diverse and complicated to handle in this forum. There are certain conditions in which the problem might be caused by a bug in the phone firmware, others where the issue is with the AP and/or WLC, etc.

Please open a TAC case and take it from there.

Thanks a lot,



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