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an issue with WLC 5508 and 7921 phone

Hello all!

I have a system with WLC 5508 and some 1242 APs. And I use a lot of 7921 phones.

One of 7921 phones was in trouble. It loses registration, disconnect conversations...

I installed the trial WLC and run voice diagnostics.

I  saw some of "Potentially degraded QoS in downlink direction because of  incorrect packet classification" messages and one "Fair upstream packet  loss ratio: 1,2%, which is less than threshold 2.5%"

As I understand all of 7921 phones in these area are affected.

what  does it mean? I set up Platinum QoS for voice WLAN. I don't have any qos  configuration string for AP and WLC ports on switches...

any ideas?

thanx in advance

Everyone's tags (5)

Re: an issue with WLC 5508 and 7921 phone


There is one application called "WLC Config analyzer". You save your "show run-config" from your WLC in a text file and import it by this application. it will analyze the file for you and tell you what recommendations for voice are missing so you improve them.

When importing a config file you choose what voice clinets you are using, so you need to choose cisco 7921 to it tells you what config improvemetns is needed based on 7921 needs.

Here is the link to download the application:

download the latest versoin.

BTW, how many voice/data clients are connected to one AP in that area? if I remember correctly if you are utilizing voice then the max number of clients connected to one AP should not exceed 17. If you have more than this number per AP try to minimize the number of users concurrently connected to the AP then try again.

Hope you'll find the config analyzer useful.

If useful please don't forget to rate.


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Community Member

an issue with WLC 5508 and 7921 phone


This application gave me nothing helpful.

I didn't see any suggestion about QoS.

but your advise about bumbers of clients on one AP is helpful.

that AP have twice more clients.

I'll try to add one-two APs to change the situation and to see the result.

Hall of Fame Super Blue

an issue with WLC 5508 and 7921 phone

Only one 7921G affected?

I do recall a discussion about a year ago.  The OP described signal issues with the 7921G after it was dropped on the floor.  The OP opened up the unit and discovered that the antenna got dislodged from the connectors.

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