Softphone problem: One-way audio

[jdean]

Just upgraded from 6.1 to 7.5 build 12.14.8701.0
All workstations running XP Pro sp2
Some agents are now getting 'one-way audio' where they can hear the person they called but that person cannot hear them. This occurs on external calls as well as from extension to extension, but not on hard phones.
I have tried the simple things such as reboots, switching heatsets, etc.

If the agent presses the mute button on their headset a few times the audio comes back, but only for a short amount of time. If the agent transfers the call to another agent the call comes back but only for a short amount of time.

As usual my Partner has no idea. Shoretel support thinks it is a network congestion issue and recommended I prioritize port 5004 on UDP. The problem with that is twofold:

1) I don't have managed switches
2) This problem does not affect all agents which to me says it is not a congestion problem.

Any suggestions?

[Rob Bush]

Odd... Because you mention that muting a few times resolves the issue temporarily, it almost sounds like a PCM client issue on the PC and not a network issue. I'm assuming you upgrade to the 7.5 PCM client along with your upgrade?

Does this happen on your actual PC? If so, could you try sniffing the traffic on your PC using WireShark (aka Ethereal) to make sure that the traffic is passing back to the phone or switch?

[jdean]

Yes, I upgraded the PCM client also. Unfortunately, the problem does not occur on my workstation. I will try to do some sniffing on one the workstations having the problem. I have never used Wireshark though, do I only sniff UDP or sniff everything?

-update - I captured a few phone calls in Wireshark and was able to duplicate the problem during them. Don't see anything unusual in the packets but I'm a newbie when it comes to analyzing packet data. One interesting note - the mute problem only occurs when I use the mute button on the headset. If I mute from the softphone, it works normally. I have a few agents testing the theory that it still might be the headsets. They are using a completely different model now. Maybe it is still something simple after all.

[eazeaz]

Headsets

Sounds like a headset problem to me.

[jdean]

Problem definitely related to headsets. I replaced a few with a completely different brand and they work fine. Now the problem is identifying the root of the problem since I cannot afford to buy 80 new headsets. Any suggestions?