Duplicate RTP frames during voice streams ?

[msrohman]

Hi all,

Our company is having difficulty with voicemail recordings on our VoIP network. A voicemail (or greeting) gets recorded to the voicemail server. However, the playback sounds slooow and synthetic.

I have a VoIP tool that captures RTP traffic and extracts the speech. I hear the same sloow and synthetic voice when I play back the capture file.

While using the capture tool, I've noticed that duplicate RTP frames seem to be getting generated during the voicemail recordings. Is it possible for Cisco switches to duplicate these frames for some reason? Could it be speed or duplex settings? I see the same thing on a 5500 at a central site and a 6500 switch on at a remote site.

Thanks,

Mike

[thomas.chen]

Mean Opinion Score (MOS) Listening Quality (LQK) is the calculated score based on concealment frames within an initial 8-second interval that is updated each succeeding second during a single voice stream.

Note: A typical MOS LQK is less than 5 and can vary based on the type of codec that the Cisco Unified IP Phone uses