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New Member

6608 QoS issues after CM upgrade

We are fighting a QoS issue on a 6608 (we think) that started after we upgraded Call Manager from 3.1.x to 4.1.3. This system has been working fine for 2-3 years until the upgrade yesterday.

Our configurations is as follows:

We have and Aspect Call Center server that connects to a 6608 in our 6500 via 6 T1 Cas connections. calls come from the PSTN into the Aspect directly. The aspect then sends them to the 6608 and they then go IP over a frame network to remote agents with IP phones.

The QoS issues are one way where the agent hears poor quality voice but the caller (from the PSTN) hears everything fine.

A couple of comments:

I know that moving to 4.1 put a new load of code on the 6608.

The 6500 is currently running 6.3.2 CatOS.

I know the recommended code from the Call MAnager compatability matrix says the CATOS should be 8.3.3 but at this time we do not have the necessary 128M DRAM to do the upgrade.

Whats the likelyhood of a code issue? Has anyone experienced anything simmilar to this?

We have checked QoS in the frame network and can't find and issues. No frame drops, Queue, drops, delay issues, etc. IP phone to IP phone across the frame works fine to the same agents that are having the problems.


Re: 6608 QoS issues after CM upgrade

many of the default parameters of Callmanager has changed.

Try changing the value strip g.729G Annex B in Cluster wide parameters of service parameter to True.

New Member

Re: 6608 QoS issues after CM upgrade

The default DSCP value for the IP phones changed, I believe, from CCM 3.1 to 4.1; it is now CS3 (you can find this under CCMAdmin -- System -- Enterprise Parameters). I can't remember what the value used to be; and I'm not too familiar with QOS setup, but I know we had to make a change to our 6509's to match the current value when we upgraded our CCM's to 4.1.3.

I found this case study with a QOS setup; it might help you:


New Member

Re: 6608 QoS issues after CM upgrade

Thanks for the response. Yes, we were aware of the DSCP value changes in this upgrade and made the appropriate changes to the network to accommodate the new DSCP values.