Troubleshooting Grandstream Phones

If your Grandstream phone is having trouble registering or is unable to receive incoming calls, this trick may fix it for you.

Change SIP Transport to TCP

Grandstream sometimes has problems using UDP as the SIP transport method. Follow these steps to change your phone's configuration to use TCP:

Telzio Auto Provisioning

If you are using Telzio's auto provisioning feature, you can easily update the phone directly from Telzio's website.

  1. Log on to your Telzio account as Account Owner, Administrator or a user with permissions to access Devices.
  2. Navigate to Devices and locate the phone with connectivity problems, then click on the device to bring up the settings.
  3. Change the SIP Transport setting to "TCP", then press Update Details.
  4. Power off the phone, wait a few seconds, then power it back on.

Manually Configured IP Phones

  1. Press the Arrow Up button on the phone. This will show the phone's IP address on the phone's display.
  2. Open you web browser and enter the IP address in the address field, then press enter. 
  3. Log on to the phone's configuration page. The default username and password are both "admin".
  4. Navigate to: Accounts Account 1  SIP Settings Basic Settings
  5. Change the setting SIP Transport Method to "TCP", then press Save and Apply