7920 an WLC 4.0.x.x

[huber]

We have Big troubles in a Customer environement. The phones reboots often and get stuck also in call. The quality of the voice is ok, but offten tere ist a lack of speech.

Conditions:

WLC 4402 with 4.0.179.11

LAP 1131AG

Phnes 7920 with latest 3.01 Software

Questions:

Is this a know issue?

Is there any deployement guide for the new 4.0 WLC Code? I have only one for the 3.2 Code.

thanks for your help

kind regards

ray

[migilles]

There was an issue in 7920 3.0 code with multiple beacons present on a channel. MBSSID is mandatory w/ Airespace unfortunately even if not broadcasting the SSID. Also was an issue w/ CCX implementation on Airespace, where neighbor list contained 802.11a radios, which 7920 didn't parse well. This is fixed in the 3.01 release.

Also ensure that aggressive load-balancing is disabled and that DHCP required is not enabled for the voice SSID.

When this occurs, check the client state. If it says DHCP_REQD, then hitting that issue.

That feature needs some additional explaining. Is more than saying "yes my clients will use DHCP". It really means that the client must re-DHCP everytime a session is ended, even via AP deauth, which could happen for many reasons (channel changes, out of range, etc.).

WLAN SRND @ http://www.cisco.com/univercd/cc/td/doc/solution/emblty30.pdf.

[huber]

I read about the issues and the fixes and also that there schould be fixed in the release we use. But the problems look exactly like this.

I have disabled the 802.11a radio and also setup the WLC with the deployement guide. no DHCP requeried no aggressiv loadbalancing and all other stuff. But nothing has changed.

But the phones still reboots and get stuck.

any other idea?

[migilles]

Sure it's rebooting? If you see Cisco logo w/ golden gate bridge then that's reset / reboot. But if you just see the spinning circle that's a restart / re-register. Would capture a wireless sniffer trace and the controller config, then open a TAC case for further assistance.

[dmaillard]

Hi Ray,

last week I installed such same scenario with 7920 Ip phones and WLC 4400. I encounter same behavior as yours where the phones are rebooting or a communication is 1 sec. cut. Moreover some of Ip phones give the message duplicate IP address on the display.

Do you have correct the issue ? Can you help me ?

Thanks a lot.

Regards,

Dominique

[migilles]

Need to address the duplicate IP scenario first and foremost. Phones will not reboot due to this, but definitely maybe lose CallManager connection and other connectivity. Should ensure ARP-caching is enabled on the controller and resolve any issues on DHCP server handing out duplicate IPs.

[huber]

Hi everybody,

The Issue on my side is still there. By the way the phon is not booting it is only tkaing new connection to Call Manager. We think the Problem is relaying to Call Manager Software. Since 11th December there is a new version of 4.2 and this we will test in the next day. I'll keep you informed about further steps on my side.

[huber]

Hi,

Now we have the CM Software 4.2.3 SR1 running and there is no change of our probleme. Yesterday we disabled some APs and set the 802.11b/g only vor 11Mbps Mandatory and above supported.

By now we encountered much less error but they are still there.

any idea?

regards

ray

[migilles]

Attach your controller config here. Also depending on the environment, may want to enable some of the lower rates to increase packet transmission success (i..e enable 5.5 as a basic rate). Also I would suggest trying to capture a wireless sniffer trace when the issue occurs.

[huber]

I have attached the sh run of the Controller. As the Problem occurs unsteady, it ist difficult to get a sniffer trace.

Thanks for looking at the conffig

regards

ray

[migilles]

I see you are using WPA-PSK with AP1130s. Should enable aironet extensions for the 7920 ssid. Advised to disable exclusion list as well. Can see quite a few b/g radios are at max power (i.e. 50mw). Also see you have LAG enabled. Have you tried disabling LAG? The rest of the config looks ok, so may want to ping TAC to assist you further, inspect traces, etc.

[huber]

Thanks for your help. I'll try to konfigure your two points this night.

Without LAG we have not tested yet.

I think the automatic Power Management will not work Properly, because there are a lot of APs and I disabled three of them to be sure not to have to much signal.

regards

ray