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Wireless 7920 phone an AP541


I seem to have problem making calls from a Cisco 7920 which is connected wirelessly to an AP541 (using latest firmware). I get a "network busy" message when I try to dial any number, even internal extensions but I can receive calls without any issues.

If I run site survey from the phone it shows this:

Channel: 1

SSID: cisco

BSSI: 61 CU: 1

On the AP I have a separate SSID created for the voice VLAN, it uses WPA and MAC isolation.

I have also looked through these forums and I can see a number of people that have these problems but none seem to have a fix, not that I could see anyway. I have also tried a different channel, was originally on chan 6 so I put it to 1 because no one else around was on that channel. - this still didn't work.

Thank you,


Everyone's tags (3)
Cisco Employee

Re: Wireless 7920 phone an AP541

The "network busy" message is due to a high channel utilization issue and would prohibit outbound calls.

However, your CU value if correct is very low.

The CU comes from the QBSS feature which would be enabled when WMM is enabled.

Can try to disable WMM and try it out.

But would recommend this if other clients are using the AP as well.

The 7920 was never supported with the AP541 and the 7920 reached end of support many years ago.

Sent from Cisco Technical Support iPhone App

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