Your Cisco SPA phone or ATA adapter reads Internal Server Error and prevents dialing out.
- Cisco SPA phones
- Cisco ATA adapters
- Lift handset (or initialize speakerphone).
- Dial * 6 8.
- Hang up.
- Wait about 30 seconds, then attempt dial out again.
Most likely, you may have attempted to use (or inadvertently dialed) an invalid or unsupported "star code," such as * 6 7 or * 6 9, which is known to cause this error.