FAQ/How can I make large traces from and to the phone

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If PCAP traces larger than 500 KB are needed, the PCAP Trace functionality of the snom phone cannot be used because of space limitations. In this case, you can still capture packets coming and going to the phone by using a PC in the same network with the phone. You will need to get all packets to and from the phone to also reach the PC, which you can achieve by:

  • either using a managed switch which supports port mirroring and mirrow all packets to the PC
  • or connecting both the PC and the phone to a hub

Once you have all packets reaching the PC, you can capture them in one the following ways, depending on whether you are using windows or linux:


  • Install Wireshark (http://www.wireshark.org/download.html)
  • Start Wireshark
  • Start capturing: click the Capture menu, choose Options, press 'Start' for the appropriate interface
  • After the test is over, stop capturing by clicking Capture -> Stop
  • Save the capture by clicking File -> Save


Install tcpdump and run it using command:

tcpdump -s 0 -w test.pcap

Optional: to only capture packets from and to a particular IP address (the phone's IP address), the command would be:

tcpdump -s 0 -w test.pcap host <IP>

(replace <IP> with your IP address)

Please refer to the Wireshark wiki for further information.

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