9971 phones reset on Wireless

[Erick Bergquist]

Hello,

We have Cisco 9971 SIP phones using wireless, and the phones reset when they are doing video calls between each other or when we set up one to do recording (built in bridge), so seems like if we have more then 1 active voice call we have problems. When we do this, the phone saids Network Busy on it then the phone resets.

We have had this issue with all firmware versions available for the 9971, currently on 9.2.2.

Have a AIR-CT5508 wireless controller with software version 7.0.98.218 and AIR-CAP3502I-A-K9 Access Points with IOS version 12.4(23c)JZ IOS on them.

I powered off all phones and PCs except for 2 phones on these APs and they still reset with Network Busy message. The SSID is set to Platinum level QoS.

What should I be looking for on the Controller or APs as to cause of this problem? The controller plugs into a 3750 switch stack which is the core.

Thanks,

Erick

[brian.kachel]

We've seen our wireless 9971's do resets when the AP's are either load balancing and forcing them to switch between access points, or if the signal strength is less than -67.

[Erick Bergquist]

Ours are not set to load balance on the voice SSID, and set to start load balancing at 20 clients I'm told, and we don't have that many.

We get "Network Busy" with just one 9971 powered on with recording enabled on the phone or doing video to another video phone (wired). With just a normal phone call we can have 12 or so 9971s all on phone call without problem, we see "Network Busy" and resets, etc when the phones are trying to do more then a single phone call / audio stream at a time.

[migilles]

Sounds like you need to increase the max stream size per client in the WLAN Controller config if 2 streams are active and it exceeds the 83200 size per stream default.

The default should handle 2 unencrypted calls (no SRTP), but believe recording uses encryption so you would need to increase the stream size.

See pages 53-55 (mainly 55) of the 9971 WLAN Deployment Guide on how to make increase the allowed stream size.

www.cisco.com/en/US/docs/voice_ip_comm/cuipph/9971_9951_8961/7_1_3/english/deployment/guide/9971dply.pdf

Call Admision Control (CAC) configuration

Voice AC - Admission control (ACM)............ Enabled

Voice max RF bandwidth........................ 75

Voice reserved roaming bandwidth.............. 6

Voice load-based CAC mode..................... Enabled

Voice tspec inactivity timeout................ Disabled

Video AC - Admission control (ACM)............ Disabled

Voice Stream-Size............................. 84000

Voice Max-Streams............................. 2

Video max RF bandwidth........................ 25

Video reserved roaming bandwidth.............. 6

The voice stream-size and voice max-streams values can be adjusted as necessary by using the following command.

config 802.11a cac voice stream-size 84000 max-streams 2

[Erick Bergquist]

We got this fixed.

We increased the max-stream bandwidth to max setting (92000 something) and max calls to 5, and had same problems and we turned off the Call Admission control on the controller and that fixed the issues.

[migilles]

Glad you have a workaround now, but disable CAC is probably not a long-term solution as it does serve a purpose.

May want to try the command I provided 84000 max stream size with max of 2 streams per client.

[Erick Bergquist]

yes, we tried 84200 and 2 streams and same problems. So we tried the max values for stream and calls and reset APs and same problem. Turned off CAC and no problems with the dozen or so 9971 wireless phones.

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[migilles]

Ok, would suggest to get a WLAN sniffer to inspect the size requested.

Would want to capture all legs.

Can open a TAC case to see further assistance.

[Erick Bergquist]

May do that in future when we need the CAC. thanks for the help.

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