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7925G voice problem.

FilipOlsen
Level 1
Level 1

Hi all

We're having a wird problem with voice quality on 7925G phones.

They are reg. on a CME 7.0 and running 1.3.3 firmware and at 5Ghz.

AP is 1242( 2 of them) and 7 phones(all 7925G).

Running QOS , used the deployment guide for 7921G , WDS and eap-fast.

This setup may run fine for like a day or 2 and then suddenly 1 phone have very bad voice quality , both ways.. literary chopped to pieces.It is impossible to have a conversation..

Signal is very strong , user/phone is allmost sitting on the AP (-40'ish)

-If dialing pstn the phone have problem

-If dialing ICT phone have problem

-If dialed pstn phone have problem

-If dialed ICT phone have problem

But if dialing/ dialed another 7925G phone LOCAL no problem.

If phone is turned off and powered back on will fix the problem.. until next time this happens. (10 min to 8 hours )

And this happens with all the phones during the week.. but never all at the same time.. not yet that is

im not sure the problem is the wireless network at all.. but related to the phone or the CME

Codec is g711ulaw

Any suggestions would be appreciated.

1 Accepted Solution

Accepted Solutions

There is a known issue with CME, where RTP is being tagged as UP4 instead of UP6 as the CME uses port 2000 for both SCCP and RTP.

This would only be an issue when the RTP traverses the CME (PSTN calls, paging, etc.), so 7921/7925 to 7921/7925 or to internal wired IP phones would not be imapcted.

Yes disabling WMM would be a short-term fix for this issue, but long-term, there has to be a fix on the 7921/7925 side.

Below is the open DDTS for this issue.

Plesae contact TAC to request 1.3.3.0.3 for a fix to this problem.

CSCtc54410 7925 with voice gaps with inbound/outbound PSTN calls

View solution in original post

10 Replies 10

George Stefanick
VIP Alumni
VIP Alumni

Are you sure its all the phones? We've had issues where we had 2 bad phones and when people with the bad phone called the people with a good working phones it gave the impression both phones were bad ...

We removed the known bad phones and life was good...

just an idea and maybe a place to start ...

"Satisfaction does not come from knowing the solution, it comes from knowing why." - Rosalind Franklin
___________________________________________________________

Hi there gstefanick.

Thank you for answering.

I know how users are when things dont work hehe.. but it is really strange and not just one or 2 phones.

Within a week all phones may have had the problem more than once.

and remember.. when a phone got this problem its with a pstn call / ICT call , but never with a local call between 7925G phones.

disable WMM on the APs when the problem is occuring, and see if that clears up the problem.

On autonomous, type this under the inteface configuration: no dot11 qos mode wmm

Hi Weterry.

Thanks for answer.

I'll try that out as soon as possible.

There is a known issue with CME, where RTP is being tagged as UP4 instead of UP6 as the CME uses port 2000 for both SCCP and RTP.

This would only be an issue when the RTP traverses the CME (PSTN calls, paging, etc.), so 7921/7925 to 7921/7925 or to internal wired IP phones would not be imapcted.

Yes disabling WMM would be a short-term fix for this issue, but long-term, there has to be a fix on the 7921/7925 side.

Below is the open DDTS for this issue.

Plesae contact TAC to request 1.3.3.0.3 for a fix to this problem.

CSCtc54410 7925 with voice gaps with inbound/outbound PSTN calls

Hello Michael.

I'll contact TAC.

Thank you and thanks to all in this conversation :-)

Leo Laohoo
Hall of Fame
Hall of Fame

Try this ...

dot11 ssid VOICE

admit-traffic

Hope this helps.

What IOS are the APs running?

Hey Leolaohoo.

Thanks for answer.

IOS Version 12.4(21a)JA1.

The admit-traffic is allrdy set.

Make sure dynamic load balancing is off on the controller. QoS is set to platinum on the voice WLAN. Inusre QoS on the wired network is configured properly. Do you get white noise too?

See my post above about the known 7921/7925 call quality issue when making calls through the CME where WMM is enabled on the AP.

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