One-Way voice path issue - 2033 Polycom units 1

[MCSUSER]

Hi all, any suggestion would be greatly appreciated.
We have experiencing intermitant one-way voice path issues with our 2033 Polycom units when making PSTN calls.
some facts:
We have a production and lab cs1000 5.0 system.
Almost always the calling party(our user) can hear the called party(intercall or PSTN ) but the called party cannot hear the calling party at all.
We have this issue in multiple locations and multiple polycoms.
Work around is to reboot the polycom.
Cannot be the FW because we upgraded one polycom unit to the latest FW and tried in the lab and within test 50 calls we were able to recreate the issue.
LAB CS1K is up-to-date in patches.
Thanks.

 

[DocVic]

What kind of background noise do you have? Anything like fans or humming power supplies. What about the placement of air conditioning vents over the unit. We have quite a few 2033's out there, and the only ones that have issues, are the ones where ambient noise is a factor. Some fans in projectors are culprits too. Remember that big ole Conference Phone 2000? that thing always worked, till the power supply smoked the room.

DocVic
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[MCSUSER]

Thanks DocVic. We don't get any noise...its like no RTP packets coming in or the unit went into a mute mode? But we know it is not muted by the users...it happened at locations with no projecotrs too like the lab.

 

[curtismo]

Make sure all your media cards have G729 enabled and Voice Activity Detection (VAD) DISABLED. I ran into this problem when I installed my first Nortel 2033 conference phone (got "fake" ringback but did not have a speechpath to the called party.

I unfortuately can't remember or find the ticket or technote on what the issue is exactly, only that I remember it involves a codec issue G.729a vs G.729ab (the Nortel/Polycom 2033 will do one but not the other) and the VAD setting enables/disables the selection. All I know is that I unchecked this and everything started working. That was on 4.5 and 6.0 is also working the same.

 

[curtismo]

Also, do you have the latest firmware (S77) on the phone? The release notes for S76 show fixes for one-way audio.

 

[MCSUSER]

Thanks curtismo. yes we have the latest FW S77. And VAD disabled as when I TRAC the unit in LD 80 i can see as VAD disabled. I have captured the packets when the issue happened so may be I can check if there is kind of codec mistamatch as you have mentioned. will add a post once have more info. Thanks R.