How to troubleshoot SIP Connection using tcpdump
To check SIP connection through tcpdump use the following command
tcpdump -nqt -s 0 -A -i eth0 port 5060
where:
-n do not convert IP address to DNS names
-q be quite, print less output informations
-t do not print timestamps
-s capture number of bytes from a packet, 0 = default iptions which is max 65535, or simply a whole packet
-A prints each packet in ASCI
-vvv be very very verbose
-i use interface to capture on
port 5060 listen for traffic ort 5060 traffic for (source and destination)
output of command