Users are reporting garbled voice mail message recordings left by callers from the PSTN.
Which of the following actions should you perform first?
A. Confirm that the connection to the caller is clear.
B. Obtain a sniffer capture at the closest point to Unity Connection.
C. Use network analysis tools to check for latency and packet loss.
D. Modify the target decibels configured in AGC.
Explanation:
When troubleshooting garbled voice mail message recordings left by callers from the public switched telephone network (PSTN), you should first confirm that the connection to the caller is clear. For example, a voice mail message could become garbled if a mobile phone caller is traveling through an area with a weak or intermittent signal. If this is the case, there is nothing you can do to solve the issue. You can confirm that the connection is clear by asking the mobile caller to place another call to the voice mail system or by placing calls to the voice mail system from other mobile phones.
If voice mail messages are still garbled when the connection is clear, you should next use network analysis tools to check for latency and packet loss. Network analysis tools enable you to determine whether the network itself is causing the garbled audio stream. For example, mismatched packet size configurations among voice devices on the network could cause packet loss or delay that might affect the quality of voice mail recordings.
As a final troubleshooting step, you should obtain a sniffer capture at the closest point of the recording to Cisco Unity Connection. This will help you determine whether the audio stream is being garbled before or after Unity Connection records it. If the stream is not garbled before Unity Connection records it, there might be a problem with Unity Connection itself.
You do not need to modify the target decibels configured in Automatic Gain Control (AGC). AGC is a Unity Connection feature that enables Unity Connection to automatically adjust the audio volume of calls. You can disable or adjust AGC settings if users report that the audio volume of voice mail recordings is always too loud or always too quiet. However, the AGC feature does not typically produce garbled recordings.
Reference:
Cisco: Troubleshooting Guide for Cisco Unity Connection Release8.x: Troubleshooting a Garbled Audio Stream in the Network