Got a 412 setup in a colocation site, using the conference center appl only via 4 T-1s. The original system installed with a VCM30 and about a year ago we tried to connect via IP trunk from our corporate Cisco Call Manager to the IPO over our MPLS network. Call setup worked fine but the voice quailty was horrible using either G729 or G711. Per a call with our Avaya support, we needed to replace the VCM but we only had a VCM5 to use, which we did and it worked fine. Good voice with the normal IP trunk noise but it worked good. So we thought great, it was fixed.
Fast forward to last week when we recieved a brand new VCM24 to use as we wanted more IP paths to save some money, Well the trouble originally found on the VCM30 came back, exactly the same issue with the new VCM24. The issue with the voice is what I would call in the old days as a HOT circuit, severly over-modulated. So in doing more troubleshooting, I brought the VCM24, VCM5 and the old VCM30 to our office where I could test it in a LAB system (IPO 403) that is also connected to our CCM and those three VCMs worked fine, the voice was great.
So a VCM5 is fine on the 412, but VCM30 or VCM24 sound terrible. Any Ideas?
ps: the 412 has been upgraded on a regular basis but we've not tried going back to the higher capacity VCM until now cause we thought we had isolated the troubles. Boy was I wrong
Fast forward to last week when we recieved a brand new VCM24 to use as we wanted more IP paths to save some money, Well the trouble originally found on the VCM30 came back, exactly the same issue with the new VCM24. The issue with the voice is what I would call in the old days as a HOT circuit, severly over-modulated. So in doing more troubleshooting, I brought the VCM24, VCM5 and the old VCM30 to our office where I could test it in a LAB system (IPO 403) that is also connected to our CCM and those three VCMs worked fine, the voice was great.
So a VCM5 is fine on the 412, but VCM30 or VCM24 sound terrible. Any Ideas?
ps: the 412 has been upgraded on a regular basis but we've not tried going back to the higher capacity VCM until now cause we thought we had isolated the troubles. Boy was I wrong
