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New Member

7920 wireless IP phone problems

I have 4 x 7920 wireless IP phone's running through one Aironet 1200 AP. This AP is very lightly used, typically only 1 or 2 laptop's use it.

When I first set the 7920's up the first one worked great, then when I tried the rest they all gave badly distorted voice on the return path, ie a caller on a 7960 hears badly distorted speech but the caller on the 7920 hears good quality speech.

The AP currently runs vxWorks 12.03(T) - I would like to convert this to IOS 12.2.11-JA but according to the "Upgrade Cisco Aironet AP1200 to IOS" document at this link:

"Versions later than 12.02T1 do not work with the Upgrade Image..." - So how do I upgrade?

Also I would like to try upgrading the firmware on the 7920 wireless IP handsets, they are currently v1.0 and I am aware version 1.3 is available and offers far greater functionality - Directories and Services for one! However I don't have the USB cable to attach a phone to my laptop, does anyone know part numbers to purchase just this cable...and can anyone confirm that if you buy the Desktop charger this can be used to perform firmware upgrade on the 7920 handsets?

Thanks in advance!


New Member

Re: 7920 wireless IP phone problems

Have you tried putting the firmware image in the TFTP folder on the callmanager?

Here is a snipette from:

Appendix: Configuring the Cisco 7920 with CallManager

The Cisco 7920 files are available on to registered users.

Copy the Cisco 7920 phone image to the TFTP directory on the Cisco CallManager server. For example, C:\Program Files\Cisco\TFTPPath\.

Copy the OS7920.txt file in the same directory. Verify that the contents of this file is a single line with the file name of the image that the Cisco 7920 will load. For instance: cmterm_7920.3.2-01-01.

Add the Cisco 7920 to the Cisco CallManager as a Cisco 7960 IP Phone.

Note: You do not need to specify the image to load.

Good Luck,


New Member

Re: 7920 wireless IP phone problems

Thanks Steve, great pointer on using CallManager to upgrade the firmware. My 7920 handsets are now firmware version 1.3 and work great. All 4 work concurrently with no reduction in call quality, exactly what one would expect!

I would still like to upgrade the Aironet 1200 AP to IOS...anyone got any ideas on this point, which was when the AP is vxWorks 12.03(T) how do you upgrade it to IOS?


Re: 7920 wireless IP phone problems

Is it not possible to downgrade to 11.x, and then migrate to IOS?

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