If you manage your own phone system (PBX) in your network, you will be asked to provide a SIP trace to SureVoIP Support to help troubleshoot call set up or call quality issues.

As Asterisk and FreeSWITCH systems generally run on Linux it is very straight-forward to gather a SIP trace.

You will need:

• root access
• tcpdump to be installed

To gather a SIP trace with signalling only, run:

tcpdump -nnp -w siptrace.pcap -i any -s 0 port 5060

This captures only port 5060, which is the default SIP port. Change this if your system uses a different port. The file will be called siptrace.pcap and will be saved in your current directory.

Press Ctrl+C to stop the trace once you have made your test call and send the file to SureVoIP Support.

If you are troubleshooting voice quality you may be asked to provide a call trace including RTP.

You will need:

• root access
• tcpdump to be installed
• you will need to know the RTP ports used by your system
  • Asterisk default is ports 10000-20000
  • FreeSWITCH default is ports 10000-40000

To capture SIP and RTP for Asterisk using the default ports run:

tcpdump -nnp -w test.pcap -i any -s 0 port 5060 or portrange 10000-20000

or to capture SIP and RTP for FreeSWITCH using the default ports run:

tcpdump -nnp -w test.pcap -i any -s 0 port 5060 or portrange 10000-40000

Make your test call and when finished press Ctrl+C to end the capture and then send the file to SureVoIP Support.

Please see 3CX SIP Trace guide (external page).

All reputable phone systems will have a method to acquire SIP traces for troubleshooting purposes. Please consult your vendor's documentation or consult with a qualified professional to assist.

• Cisco - Packet Capture on CUCM Appliance Model

For PBX software running on Microsoft Windows, we suggest using Wireshark to obtain SIP traces.

There may be times when a SIP trace from a handset is required.

• Yealink
• Cisco SPA500 and SPA300 Series (external link)
• Snom (external link)

There are several tools you can use to obtain SIP traces, such as:

• sngrep (widely available for all Linux distributions)
• tcpdump (widely available for all Linux distributions)
• ngrep
• pcapsipdump
• Wireshark
• DrayTek Router port mirroring (external link; login required)