CHANGES:
add in-band busy and congestion tone detection
add +FAR=2 feature to detect received V.21 HDLC while sending them
improve and extend jitter coping
help some instances of fast train by being careful about jitter cope
add +FRCNG responses for CNG detection during +FRH and +FRM commands
allow for ATD to be used during a call
fix build warnings and validate the session before calling
iax_send_voice, iax_answer, and iax_hangup
refactor DTMF presentation code
The source code for IAXmodem can be downloaded here: http://sourceforge.net/project/showfiles.php?group_id=148814.