How to make a SIP Trace for Troubleshotting…?

From asterisk cli run: sip set debug on

To save in a file, from linux shell: asterisk -rnvvvvvddd | tee <yourdesiredname>.txt
You will enter to the asterisk cli as usual, again run the sip set debug on when you finish exit from asterisk cli. In the folder where you run the command you will see a file calles .txt

With tcpdump from linux shell: tcpdump -w <yourddesiredname>.cap -p -n -s0
To finish the capture press ctrl+c, you will see a file called .cap then you can open in wireshark you can trace the sip flow, listen the call or see a graphical view of sip requests.