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New Member

Popping sound problem


Hardware Config: (1) Dell 2500 / Intel 8255x-based PCI (2) IBM x232 / IBM Netfinity 10/100

Software Config: (1) Unity 3.15, TSP 6.02a (2) Unity 3.13, TSP 6.01

Two of our customer sites suffer from popping sound that occurs serveral times per month. According to the white paper, it is related to the Unity NIC card problem but TAC Case collection claims it is related to the sampling rate for the codec and QoS.

It seems the description in white paper matches our case, because the phone to phone communication is no problem in general. If it is really the NIC problem, does it mean I have to update the newest NIC driver?

Pls advise. Thx a lot.


  • Other Collaboration Voice and Video Subjects
Cisco Employee

Re: Popping sound problem


Where there might be two NIC's on the server, be sure only one is the active NIC (It's ok to use the other for fault tolerance, but no teaming per: )

If you see overruns or alignment errors on the switch, make sure both the switch port Unity is using and the NIC have their duplexing hard-coded.

Using 'auto-negotiate' on the NIC is not recommended.

As for the NIC driver, there was an older issue w/ Compaq's driver described here with other NIC related troubleshooting:

To be sure the hardware itself is not at fault - switch to a second NIC if one is present or you have an open slot for a temp PCI NIC.

If you have a sample wav file of the distortion, please send a copy to I'll review and compare with any other known distortions.

New Member

Re: Popping sound problem


I should mention that only the voice message is affected by popping sound problem but not system greetings (e.g. leave your message after a beep tone ... etc)

Thx a lot

p.s. My colleague, Henry, has sent you the voice sample of distortion.

Cisco Employee

Re: Popping sound problem

There are a couple of possibilities for the silence insertions that create this 'popping'. The link here describes the generic issues for troubleshooting such an issue:

I'll reply to Henry with more details on how the distortion in the sample I received might be further isolated & resolved.

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