7920 jitter on WLC 4.1.171

Unanswered Question
Jul 30th, 2007
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We have 2 x 3750 with integrated controllers, 8 x 1131 AP's, and approximately 35 x 7920 phones.

We have an issue with Jitter and occasional phone freeze with no button response for approximately 1 minute.

We are using the following QoS settings:

WMM state: disabled

QoS level: platinum

DSCP: disabled

802.1p Tag: 7

We get the following readings from the phones:


Average Jitter 40

Maximum Jitter 60



Average Jitter 35

Maximum Jitter 55



Average Jitter 75

Maximum Jitter 95



As you see Jitter is always above the 30ms recommended.

Any help would be really appreciated



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migilles Mon, 07/30/2007 - 13:25
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  • Cisco Employee,

Sounds like you don't have 3.01 or later deployed on the 7920s.

Suggest using 3.02. Some fixes in 3.01 due to IAPP and MBSSID w/ Airespace 4.0.

Will be some jitter when the phone is scanning off-channel, but will not be noticeable to the human ear.

Also some jitter when roaming from AP to AP depending on the authentication type.

For controller version, would recommend or later.

dazzo Mon, 07/30/2007 - 23:51
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Sorry forgot to mention....already using 3.2 and as per the subject title, using 4.1.141 on the WLC.

We are currently using WPA for encryption, and MAC filtering.

kadambari.beelw... Tue, 07/01/2008 - 11:01
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I have a wireless set up for customer with

3560 (laod balanced) and WLC and AP with 7921.There are occasions where the jitter value on the phone reaches as high as 650 and 7921 (1.1.1) phones cannot hear anything.

How do we pursue this issue?We have checked LAN and no congestion issues are noticed.

Can you pls help?


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