Voice Quality Issue with Cisco IP phone 7821 series

[Nguyen KeThuc]

Hi all,

I have CUCM 10.5 with Cisco 7821 and 7945 endpoints. Internal calls are fine. However, I get voice quality issue with outbound calls from Cisco 7821 endpoint. The lost packet rate is always about 2 % with just Cisco 7821 series. Meanwhile, I don't get any lost packets with Cisco 7945 endpoints in same outbound calls. My attached files are call statistics of them.

I also try to test by moving the Cisco 7821 the  closest with the voice gateway ( same switch). But, there is still lost packets.

Any ideas for me?

Thuc

[Manish Gogna]

Hi Thuc,

If you have already tested with the latest firmware of 7821 then you may need PCM capture from the gateway to check which side is causing the issue.

www.cisco.com/c/en/us/td/docs/ios-xml/ios/voice/voiceport/configuration/15-mt/vp-15-mt-book/voi-pcm.html#GUID-58294EF2-A10B-4883-AB6C-5C2C30C33509

HTH

Manish

[Nguyen KeThuc]

Thanks Manish,

Do you doubt lost packet from PSTN side? Follow your link, I will capture the call in my voice gateway. Then what will I do next?

Thuc

[Manish Gogna]

You can either open a TAC case to get them analyzed or you can try an alternate method described below

http://www.cisco.com/c/en/us/support/docs/voice-unified-communications/unified-communications-system/115749-analyze-pcm-data.html

HTH

Manish

[Nguyen KeThuc]

Thanks for your advice.

Thuc

[shane.orr]

Did you find a fix for this?

I also have 7821 phones and see similar issues on occasion.