Troubleshooting a Grandstream UCM SIP trunk is crucial for ensuring smooth communication. If the trunk shows as Unreachable or there's no audio, it could be due to several factors including codec mismatch, NAT settings, and SIP ALG on your router.

Check Trunk Status in UCM Dashboard

  1. Step 1: Log in to UCM Dashboard

    Use your credentials to log into the Grandstream UCM administration interface.

  2. Step 2: Navigate to Trunk Status

    Go to the menu where you can view the status of all configured trunks. This is usually under a tab labeled "Trunk", "SIP Trunks", or similar.

  3. Step 3: Check Trunk Status

    Check if the trunk is marked as "Registered". If it shows "Unreachable" or has other error messages, there's a connection issue.

Trunk Shows Unreachable or Registration Errors

  1. Step 4: Verify SIP Credentials

    Ensure the SIP credentials in UCM match those in your Internetport customer portal. You can find these at https://portal.internetport.com -> Services -> My Services -> [SIP Trunk] -> Configuration Details.

  2. Step 5: Verify SIP Server Configuration

    The SIP server should be set to sip.internetport.se with ports 5060 UDP / 5061 TLS.

Enable SIP Debug Log in UCM

  1. Step 6: Enable Debug Logs

    Navigate to logging settings and enable SIP debug logs. This will provide more information about the issue.

One-way Audio or No Audio - RTP Codec Mismatch

  1. Step 7: Check Configured Codecs

    Ensure the codecs configured in UCM are supported by Internetport. Supported codecs are G.711 a-law (PCMA), G.711 u-law (PCMU), G.722, and G.729.

  2. Step 8: Adjust Codec Priority

    If there's a codec mismatch, you may need to adjust the priority of the codecs used in UCM.

NAT Settings - External IP and Local NAT

  1. Step 9: Check NAT Settings

    Ensure NAT settings in UCM are correctly configured. If using a router that performs NAT, make sure it has the correct port forwarding.

  2. Step 10: Use STUN Server

    Use Internetport's STUN server stun.internetport.se to help with NAT traversal.

SIP ALG on Router - Turn it Off

  1. Step 11: Check SIP ALG Settings

    Check if SIP ALG (Application Layer Gateway) is enabled on your router. If so, try disabling it as it can sometimes cause issues with SIP communication.

Contact Internetport Support with the Right Info

  • If you've followed all the above steps and still have issues, contact Internetport support for assistance. Be sure to include relevant logs and information about your configurations.

For more help, visit Internetport support.