Hi,
I’m developping a C application that would allow me to create a socket and bind it to the port 5060 so that I can display all the messages that my Asterisk receives. So far, I can connect to 5060 but nothing is displayed.
First, is it possible to do what I’m trying to do? 
If yes, is there any specific way to do that other than the traditional UDP listening port method?
Thank you very much for your help.
Cheers.
*CLI>sip set debug on does not do what you need ? If not I suggest picking a copy of ISBN 0201633469
Only one file descriptor can bind to any specific combination of port and interface at a time. If that file descriptor is read from one process, the message is read for all processes.
Most OSes have a diagnostic mode where all network traffic can be intercepted, as used by tcpdump and wireshark, and with lower level access with libraries like libpcap.