VoIP Connectivity Troubleshooting

📞 Troubleshooting Guide: VoIP Call Quality Issues

If you're experiencing poor call quality, dropped calls, or audio problems using our VoIP system, this guide will help you identify where the issue might be. Please follow the steps below before reporting the problem to support.

1. 🔌 Basic Checks

Before looking at the network, try the following:

• Check the phone and cables: Make sure the handset is switched on and all cables are secure.
• Restart your router/modem: Unplug them for 30 seconds and then reconnect.
• Test other devices: Is your internet working fine on other computers or phones?
• VPNs: If you're using a VPN, disconnect it and test without it.

2. 🌐 Check Your Internet Connection

VoIP needs a stable and fast connection.

✅ Run a Speed Test

• Visit speedtest.net
• Test using UK-based servers
• Record Download, Upload, and Ping

Recommended Results:

• Upload speed: At least 1 Mbps per call
• Ping: Under 100ms
• Jitter: Under 30ms

If your results are below this, contact your internet provider.

✅ Run a Ping Test

• Windows: Open Command Prompt
  Type: ping sip.voip123.co.uk -n 20
• Mac: Open Terminal
  Type: ping -c 20 sip.voip123.co.uk

Look for:

• Low latency (<100ms is ideal)
• Stable response times
• 0% packet loss

3. 📶 Check for Network Congestion

If too many devices are using your internet at once, VoIP may suffer.

Ask:

• Are people streaming video (Netflix, YouTube)?
• Is someone downloading/uploading large files?

Try pausing other activity and see if call quality improves.

4. 📤 Check for Packet Loss

Packet loss causes voice distortion or dropped calls.

Run a Packet Test (Windows only):

In Command Prompt, type:
pathping -n sip.voip123.co.uk

If any hop shows >5% packet loss, that’s likely the issue.

Try:

• Restarting your router
• Using a wired connection instead of Wi-Fi

Still no improvement? Contact your ISP with your results.

5. 📍 Check Latency & Routing

Run a Traceroute:

• Windows: tracert sip.voip123.co.uk
• Mac: traceroute sip.voip123.co.uk

Look for:

• Sudden spikes in response time (>200ms)
• Repeated timeouts

These indicate routing issues on the way to the VoIP server.

6. 📊 Check Your Router Settings

QoS (Quality of Service)

Some routers allow you to prioritise VoIP traffic:

• Log into your router settings (use the IP and login on the back of your router)
• Find the QoS section
• Set VoIP or SIP/RTP packets as High Priority

SIP ALG

• Find SIP ALG in router settings
• Disable it if possible (see your router manual)

7. ☎ Contact Your ISP

If you’ve confirmed problems like packet loss or poor speeds:

• Give your ISP the results of:
  • Speed test
  • Ping test
  • Traceroute
  • Pathping (packet loss)

Ask them to check for:

• Network congestion
• Routing issues
• Service disruptions

8. 🔁 Final Steps

If nothing helps:

• Try another network (e.g. mobile hotspot)
  If the call quality is better, the issue is with your internet.
• If issues happen on all networks, the problem could be with:
  • The handset or
  • The VoIP provider

Please send your test results when reporting the issue so we can help you more quickly.

📋 Quick Summary