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New Member

silence from unity port

I have a 3.1(5) unity with a 3.2(2c) call manager.

Users can not dial into voice mail. When the msg button is hit, the display says connecting to voice mail port, nothing is heard, and then the call is dropped. If I reset unity, it starts working again, and then fails in about an hour. this started happening the other day.

In the event viewer I see an avmiu_mc error 530:

Component Miu: Thread 0x00000E94 had a Failure on Port 6 in AvWav


File: e:\views\cs_UE3.1.4.39\un_Miu\UnityAvWav\wavtrace.h(124)

Method: WavReadFormatSpeed

Failure: call to WavReadFormatPlay failed.

Anyone know what's happening?



Cisco Employee

Re: silence from unity port


This sounds like an issue with codecs from the one event and the problem described. Are the phones in the same region as your voicemail ports? If so, is the region g711 or g729?

If you desire a g729-g729 connection between the phones and Unity, make sure Unity's record format is set for g729 and the codec is installed on the Unity server (this will be obvious from Application events during startup for each of the TSP ports stating 'g729 enabled').

Anyone using g729 will want the latest codec from the CCO download site (CCO registration req'd):

And the readme here:

Other codec considerations are documented here:

Hope this helps!

New Member

Re: silence from unity port

yes. seems to be.

the phones that stopped working are in different region than unity and are using g729 codec. phones in same region use g711 and continue working when the others fail.

why does it work for a while & then stop ? will this codec fix it?



Cisco Employee

Re: silence from unity port

Great - Given we know g729 was working for these users, then stopped, you are most likely experiencing issues related to the older g729 codec version.


The g729 codec from VoiceAge version is verified to correct errors associated to the multi-stream usage of the codec common on Unity systems juggling more than one g729 call at a time.

Installation of the new codec does require a system reboot.

New Member

Re: silence from unity port

seems to be working!

I installed codec and rebooted about 2 hours ago and so far, so good



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