Core Issue
This crackling sound is often caused by the use of a cable that has a poor electrical connection.
Resolution
Replace the cable to resolve this problem. If replacing the cable does not resolve the problem, perform these steps:
- Identify and eliminate the electrical interference or faulty power supplies.
- Identify and eliminate any digital errors occurring on the line. These can be identified on the Cisco IOS gateways by issuing the the show controller t1/e1 command.
- Also look for hardware issues, such as failure of the port or controller.
For more sample voice quality symptoms, refer to Recognizing and Categorizing Symptoms of Voice Quality Problems.
