Audio Feedback from Office -> Home

[StephenIT]

We're running MGC V8.0.2 and have no feedback between offices and no p2p feedback while not in the office. We have a VPN setup so users can join in office VC's but have horrible feedback issues. Sometimes it's so bad that the audio becomes useless and the user has to call in. Any idea where to start on a problem like this? I was guessing either QoS settings on the office routers or an issue from connection through a VPN to the office.

Please help,

Stephen

[Joe Vallender]

What is the VPN users' video setup? Could it be as simple as their microphone picking up the speaker output? What happens if you block the audio from the MCU to the VPN user, does that stop the feedback?

[shogun2]

Maybe something like this:

http://clearone.com/personal-usb-speakerphone.html

plugged into the home computers would do the job.

[StephenIT]

The home users are using Polycom Communicator c100 with built-in echo cancellation on the device. The device is a mic and speaker built-in together. I'll try a few of the things you mentioned as well and post another reply. Thanks for the feedback (no pun intended!).

Edit: The VPN users on the server are just setup like any normal VPN group. Then we setup a normal vpn through adding a new network on the home users account, give them the IP address for the VPN and the username and password for their account. They can connect fine through the VPN and have audio/video. But the audio can get very choppy with feedback and delay issues. The same mic/setup works fine if we do a home to home (p2p) call or office to office call all within the same POLYCOM environment. The issue is when someone from home tries to give a presentation (not listen, because that part seems fine). The main problem is when the presentor is at home talking to people in the office. Hopefully this makes a little more sense. That is why I don't think it is a mic/speaker issue.

Thanks

[Wise82Guy]

Are the VPN users on PVX clients, or something else?

[StephenIT]

They are using Polycom PVX as well. I just did a test call from office to home not using our MGC and on the VPN. This was a p2p connection through vpn and it sounded fine. The main problem is when we run it through the MGC and the user at home has the issues.

[Shawn Jones]

They are using Polycom PVX as well. I just did a test call from office to home not using our MGC and on the VPN. This was a p2p connection through vpn and it sounded fine. The main problem is when we run it through the MGC and the user at home has the issues.

Sounds like a look at the echo cancellation settings on the MGC are in order.

Is there a default h.323 call setup that you are using for the PVX systems that would make echo issue occur?

Can you dial a P2P through the bridge and not go out on the VPN?

Have you traced packets, and could they possibly be bouncing back with a mis-addressed header causing this?

Is there a route issue with the MGC that doesn't happen with the P2P call?

Divide and conquer...:pirate:

[StephenIT]

Sounds like a look at the echo cancellation settings on the MGC are in order.

Is there a default h.323 call setup that you are using for the PVX systems that would make echo issue occur?

I'm not sure how to check this, i'm not really POLYCOM savvy yet. I don't know that we have anything other than default settings for call setup.

Can you dial a P2P through the bridge and not go out on the VPN?

I tried to get the bridge to call my home IP address and I couldn't get it to work. Soon as I connected to the VPN it worked fine.

Have you traced packets, and could they possibly be bouncing back with a mis-addressed header causing this?

I'm not quite sure how to do this, any recommendations on a packet tracing proram?

Is there a route issue with the MGC that doesn't happen with the P2P call?
Looking into this right now. I have a network person looking at the end where the MGC is locatd (in a DC in another state).

Divide and conquer...:pirate:

Thanks for your help. Any other recommendations would be greatly appreciated. Right now i'm upgrading the VSX 7000a units we use in the office and will upgrade the MGC to version 9.0 next week.