Troubleshooting for Audio and Voice Quality Issues

Clear and stable audio is essential for effective communication. However, network instability, incorrect device configuration, or SIP (Session Initiation Protocol) related issues can sometimes impact call quality.

This section covers common sound and voice transmission problems, including unclear audio, one-way sound, delays, jitter, and frequent call drops. Each issue is explained with possible causes and recommended troubleshooting steps to help restore optimal call performance.

In this Article:

• Phones Have Quality Issues
• Phones Are Experiencing One-Way Audio
• Phones Are Having Delayed Audio 
• Phones Are Experiencing Jitter
• Phones Are Dropping Calls Frequently

Phones Have Quality Issues

✅ Check Network Stability 

• Run a speed test (Upload/Download). 
• Look for high latency (>150ms), jitter (>30ms), or packet loss (>1%). 

✅ Switch to a Wired Connection (If on Wi-Fi)

• Wi-Fi VoIP phones may experience interference and latency issues.

✅ Verify Headset/Speaker Connection

• Check for loose cables or try another headset. 

✅Restart the Phone and Network Devices: 

• Power cycle to refresh network routing. 

Phones Are Experiencing One-Way Audio

✅ Check Network Configuration 

• Ensure SIP ALG (Application Layer Gateway) is disabled on the router. 

✅ Test With Another Call 

• Call another extension to see if the issue persists. 

✅ Verify Codec Settings

• Ensure supported codecs like G.711 or G.729 are enabled. 

✅ Restart the Phone and Network Devices 

• Refresh connections and re-register SIP settings. 

Phones Are Having Delayed Audio

✅ Run a Network Speed Test

• Check for high latency (>150ms) and jitter (>30ms). 

✅ Use a Wired Connection 

• Wi-Fi networks introduce delay use Ethernet for VoIP. 

✅ Check for High Bandwidth Usage

• Ensure no downloads or streaming are affecting bandwidth. 

✅ Restart the Router and Phone 

• Refreshes the network path for better audio performance. 

Phones Are Experiencing Jitter

✅ Run a Jitter Test

• Use an online VoIP test tool to measure jitter. 

✅ Prioritise VoIP Traffic in QoS Settings 

• Enable Quality of Service (QoS) for VoIP packets. 

✅ Use a Wired Connection

• Wi-Fi often introduces jitter use Ethernet. 

✅ Restart the Phone and Router

• Clears network congestion. 

Phones Are Dropping Calls Frequently

✅ Check Network Stability 

Run a continuous ping test to the VoIP server.

✅ Verify SIP Expiry Timer 

Increase SIP expiration to 3600 seconds to prevent re-registration drops. 

✅ Restart the Phone and Router

Refresh connections and re-authenticate SIP settings. 

✅ Check for Firmware Updates 

Outdated firmware can cause call drops. 

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