Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. And see here for current known issues.

New Member

Unity VM volume fluctuation

When a user picks up a message (random users random messages) the voice volume will fluctuate up and down.

I am running Unity 3.1 Build 3.1(4) and a PRI to PSTN on a 3725.

If anyone has encountered this and found a fix please let me know.

Thank you,


New Member

Re: Unity VM volume fluctuation

We see a few cases on this every now and then. What version of TSP on Unity and Call Manager are you using? What are you using as a voice gateway? Have you tinkered with your input gain and output attenuation settings on the gateway?

How often does this happen? Can you reproduce it? Does this happen during regular phone conversations? Have you taken a sniffer trace of a bad call? There are audio tools out there that will allow you to strip the audio stream out of a sniffer trace and listen to it.

For an immediate workaround, make sure AGC is enabled and run the SetVolume utility. That will normalize the incoming audio.


New Member

Re: Unity VM volume fluctuation


GW: PRI on a 3725 IOS 12.2(13)T with a 1T1, PRI NI2

CM (PUB/SUB) is 3.2.2c with all the updates and patches as of December.

Unity info:

Unity server name = IOGEN902

Back end is Exchange 2000

Companion Exchange Server = xxx

Unity domain =xxx

Global Catalog Server=xxx

Domain Controlers:


Unity version = 3.1(4.0)

Cisco Unity TSP version =

Exchange version = Exchange 2000 build: 5762: SP 2

SQL Version = Microsoft SQL Server 2000 - 8.00.474 : SP 1 + HF 1

Windows version = 5.0 Build 2195: Service Pack 2

Switch 0 = Cisco0002.INI

Switch 1 = Cisco0002.INI

Ports configured = 16

Default recording codec = 8K Mu-Law

TUI Languages loaded = ENU,FRA

GUI Languages loaded = ENU,FRA

TTS Default Engine = LnH

Total Subscribers = 161

Total Call Handlers = 8

Total subscribers homed locally = 161

1.I cannot reproduce the problem it happends at random times to random users.

2.It happends often enough that my users are complaining that they cannot understand their voice messages.

This just started to happen sudenly (last 3-4 weeks).

Thank you,


New Member

Re: Unity VM volume fluctuation

If this "started to happen suddenly" a month ago, then think back to what changed around then. Did you upgrade the call manager or unity server? Swap out a voice gateway? Any network changes? More phones? Anything? Stuff like this doesn't start happening on its own.

We have an audio troubleshooting guide I recommend you read through.

Make sure your AGC settings match the recommendation (especially AGCsampleSize), and run the SetVolume utility.