Dialtone lost after short hangup


I recently upgraded our Asterisk system to 1.4 and got all but a few glitches working.

One issue I’m having is that if a phone is hungup for 3 seconds or less and then picked up again, a dialtone is never established. Instead there is a computerized squeal and then silence. A second hangup attempt corrects the problem, or hanging up for 4 seconds seems to prevent this problem from occurring.

When this issue occurs, the asterisk console reports:
[Feb 6 13:21:05] WARNING[2488]: chan_zap.c:1642 zt_set_hook: zt hook failed: Device or resource busy

Is there some timeout parameter I can set so that dialtone will be established even after hanging up for 1 second? Or if I could set it up to be interpreted as a “flash” that would also work.


Mark MacVicar