Hardware Echo Canceller Woes

Asterisk Asterisk Support
1

We have been using the TDM400 cards for a while. Recently, we installed our first TDM410 with the hardware echo canceller.

Here are the issues we ran into:

  1. Phantom calls. Solved by patching zaptel.
  2. The system doesn’t hang up on a far end disconnect. Solved by firmware update.
  3. If I am on a call, and there is ambient noise in my office, the far end of the call gets muted, and I have one-way audio. It seems to be the hardware echo canceller, since if I turn it off, the problem goes away.
  4. With the echo canceller turned on, and I call a system that uses DTMF, it won’t recognize DTMF from our end. Again, turning off the HWEC fixes it.

Any suggestions (other than ditching the HWEC?)

Asterisk 1.4.21.2
Zaptel 1.4.11
Libpri 1.4.6

2

Just for giggles, tried a Sangoma A200D. Same issue with echo cancellation.

If I am on a call, and there is ambient noise in my office, the far end of the call gets muted, and I have one-way audio. It seems to be the hardware echo canceller, since if I turn it off, the problem goes away.

Anyone have any ideas on what else to try? I had the telco in and they say the lines are OK.

3

I guess you could try oslec, I am not to sure if it will help, because I dont have hardware echo canceller.

rowetel.com/ucasterisk/oslec.html
pbxinaflash.com/forum/showthread … 100&page=3

4

Actually, the oslec one works much better than the hardware echo cancellers.

I’d still like to figure out why.

Has anyone else run into issues with the hardware echo cancellers not working?

Does anyone have any suggestions that I can try?