tcpdump -nqt -s 0 -A -i eth0 port 5060 -w /tmp/dump.pcap
tcpdump -qns 0 -A -r /tmp/dump.pcap
apt-get install ngrep sipgrep sngrep.
ngrep -d any -p -q -W byline port 5060
sipgrep -d any -t 019 -G
sngrep # all
sngrep -c # only when invite
tcpdump -i eth0 portrange 5060-5061 and outbound -vv -s 0
tcpdump -i eth0 portrange 5060-5061 and inbound -vv -s 0