Error 480 “Temporarily Not Available” on Ribbon EdgeMarc 6000 PRI Trunk

Symptoms

• Outbound calls fail intermittently.
• Call attempts return the error:
• 480 Temporarily Not Available
• The error is received from the PRI trunk.
• Inbound calls may continue to work normally.
• No configuration changes were made prior to the issue occurring.

Environment

• Device: Ribbon EdgeMarc 6000
• Trunk type: PRI
• Connectivity via PRI ONT device
• Issue observed during outbound call attempts

Root Cause

The issue is caused by a temporary glitch or lock-up condition on the PRI ONT device.
When this occurs, the ONT stops responding correctly to outbound call signaling, resulting in the 480 Temporarily Not Available error being returned to the EdgeMarc.

This behavior is not related to:

• EdgeMarc configuration
• PRI trunk provisioning
• Call routing or dial plans

Resolution

Rebooting the PRI ONT device resolves the issue.

Steps:

1. Identify the PRI ONT device connected to the EdgeMarc 6000.
2. Perform a controlled reboot of the PRI ONT.
3. Allow the device to fully reinitialize and re-establish PRI signaling.
4. Place a test outbound call to confirm normal operation.

After rebooting the PRI ONT, outbound calls should complete successfully without returning the 480 error.

Verification

• Confirm outbound calls are completing normally.
• Monitor call logs on the EdgeMarc for the absence of 480 Temporarily Not Available errors.
• Verify PRI status is stable and in service.

Additional Notes

• This issue may recur if the PRI ONT experiences similar glitches.
• If the problem becomes frequent, consider:
  • Firmware review or upgrade of the PRI ONT
  • Escalation to the PRI service provider for further investigation
• No reboot of the EdgeMarc 6000 is required in most cases.