Hang ups during conference call

We’re using SPA 941 phones with asterisk 1.4.16 and FreePBX 2.3. All of the phones are having problems while on a conference call with freeconferencecall.com (not sure if it’s specific to this provider or not, but figured I should mention it).

At various points during the call (just had three different users get knocked off during the same call) a user will here a long beep (like a button was pressed) and gets knocked off the call.

It seems to be fine when you are on a point-to-point call, but on conference calls, whether you are speaking or not, it happens. One of the guys has the SPA 941 plugged into the router next to his vonage box and vonage has no such problems, but he gets knocked off all the time.

Any ideas or suggestions where to look?


Are you running ztdummy ? What are the specs of the machine ?

cli output as this is happening…


How are you connecting to freeconferencecall.com if you are dialing in via voip trunks from * it could be rtp timeouts.

Personally I would speak to freeconferencecall.com and log a call with them.