Starting from firmware version 8.7.5.9 all the Snom Desktop phones equipped with one or more USB ports can store SIP traces on a mass-storage device connected via USB. In this case the trace size is limited to the USB device free space only.


In order to enable this feature you need to

  • enable theĀ usb_storage_siptrace phone setting
  • create a flag file named siptrace.flg on the USB device root directory
  • plug the USB device into the phone

Step-by-step guide:

  1. Enable the usb_storage_siptrace: you can do it via provisioning or via phone web interface clicking on Advanced -> QoS/Security:


  2. Create the "flag file" siptrace.flg into the root directory:
    Unplug the USB device from the computer (please follow the required steps to safely unplug the device).

  3. Plug the USB device into the phone USB port, the phone should detect the storage device:


  4. At this point the phone starts saving the sip trace on the USB device, once you reproduced the issue you can unmount and unplug the USB device. Unmounting the device before unplugging is fundamental in order to avoid data corruptions.
    The USB device can be un-mounted pressing the Menu key, selecting Maintenance and thenĀ Unmount USB disk

  5. Now your are ready to plug the USB device into your computer and start analysing the saved SIP trace: