Call transfer and ## key timing


I have asterisk v 1.4.16 up and running.
The detection of two # keys in a sequence to transfer a call seems to be dependent on how quickly I press the keys.

If I press the keys in a casual slow (1/2 second) mode between the keys, there is no call transfer. But if I press the keys as quickly as possible, viola, there is a call transfer.

I searched around for any docs, but I just can’t find any such info on how to adjust the timing between the key presses. I think there must be some timing setting either configuration or hard coded must be there because dialing the phone numbers allows much slower pace.

Can someone please point me to a doc showing how this is done or explain it if it’s not documented.

TIA for any feedback.

Well, after browing through the source code I found some hard coded values.

Then I came across this disappointing info from Since the topic of DTMF seems to be such a troublesome topic a configurable info would have been easier to play with.

Modify DTMF timing
Q: How and where can I adjust the DTMF timing?
A: main/channel.c, include/asterisk/channel.h: 2007-04-24 21:34 +0000 [r61781-61787] Russell Bryant (Asterisk 1.4.3)
Improve DTMF handling in ast_read() even more in response to a discussion on the asterisk-dev mailing list. I changed the enforced minimum length of a digit from 100ms to 80ms. Furthermore, I made it now enforce a gap of 45ms in between digits. These values are not configurable in a configuration file right now, but they can be easily changed near the top of main/channel.c.