ToDo List (no order):
 - fix: wrong nonce value after aprox. 2000 users
 - fix: after aprox. 3 users the password is missing except -p was set
 - add displayname support to  parse_uri
 - check the request target for the ACK
 - add option to tear down INVITED calls with BYE
 - add support for CANCEL
 - add support for spoofed IPs
 - parse the complete DNS resonses in util
 - increase hostname detection for the Via line
 - add support for priority and weigth in SRV responses
 - endless randtrash mode with logfile
 - support for IPv6
 - strict RR support

Feel free to send me patches for this (or other) features!