Troubleshooting Network & Connection Issues

Introduction

If you're experiencing choppy voice, one-way audio, or cannot make calls at all, the issue may lie within your Local Area Network (LAN). This includes your router, cables, and Wi-Fi environment.

Before diving into complex troubleshooting, it's important to understand that VoIP calls are sensitive to network conditions. Your router must be properly configured to prioritize voice traffic over other data like streaming or downloads.

This guide will walk you through systematic steps to identify and resolve network-related issues affecting your VoIP service.

✅Quick Checklist

Start with these basic checks before proceeding to detailed troubleshooting:

• Restart your router and modem (unplug for 30 seconds, then plug back in)

• Verify all cable connections are secure (Ethernet cables, power cables)

• Ensure no large downloads or uploads are running during calls

• Check if other devices on your network are experiencing similar issues

🛠️ Step-by-Step Troubleshooting Guide

1. Optimize Your Router Settings

Your router plays a critical role in VoIP quality. Two settings are particularly important: Quality of Service (QoS) and SIP ALG.

Enable Quality of Service (QoS)

QoS ensures that voice traffic gets priority over less important network activities like web browsing or video streaming.

Why this matters: Without QoS, a large download could starve your VoIP call of bandwidth, causing choppy audio or dropped calls.

To enable QoS:

1. Access your router's admin interface (typically http://192.168.0.1 or http://192.168.1.1)

2. Log in with your admin credentials

3. Look for QoS, Traffic Management, or Bandwidth Control in the settings

4. Enable QoS and prioritize traffic by:

   • Device: Add your VoIP phone's MAC address

   • Application: Select VoIP or SIP if available

   • Port: Prioritize UDP ports 5060-5061 (SIP) and 10000-20000 (RTP)

5. Save your settings and restart the router

Note: Router interfaces vary by manufacturer. Consult your router's manual or support site for specific instructions.

Disable SIP ALG

Many routers include a feature called SIP ALG (Application Layer Gateway) that was designed to help VoIP traffic pass through firewalls. Unfortunately, it often causes more problems than it solves.

Important: SIP ALG frequently interferes with call signaling, leading to one-way audio, dropped calls, or registration failures. Disabling it is strongly recommended.

To disable SIP ALG:

1. Access your router's admin interface

2. Look for Advanced Settings, Firewall, or NAT

3. Find SIP ALG, SIP Passthrough, or SIP Helper

4. Disable this feature

5. Save settings and restart your router

Common router brands and where to find SIP ALG:

• Netgear: WAN Setup > Disable SIP ALG

• Linksys: Administration > Firewall > Disable SIP ALG

• TP-Link: Advanced > NAT > Disable SIP ALG

• Asus: WAN > NAT Passthrough > Disable SIP

2. Check Your Cables & Wiring

Faulty or unsuitable cables are a common but often overlooked source of VoIP problems.

Inspect All Cable Connections

• Examine all Ethernet cables connected to your phones, router, and computers

• Look for signs of physical damage, wear, or corrosion

• Ensure all connectors are securely plugged in

Avoid Cable Splitters

While splitters might seem like a convenient solution, they can introduce:

• Signal degradation

• Jitter and latency

• Intermittent connection issues

Best practice: Connect each device directly to its corresponding port without using intermediary devices.

Use Quality Ethernet Cables

For reliable VoIP service, use CAT5e or CAT6 cables. These provide:

• Replace any worn or damaged cables immediately

• Keep cable runs as short as practical

• Avoid running Ethernet cables parallel to electrical wires to prevent interference

3. Optimize Your Wi-Fi Environment

If you're using wireless VoIP phones or softphones on Wi-Fi, your wireless environment significantly impacts call quality.

Router Placement Tips

Did you know? Common household devices like microwaves, cordless phones, and baby monitors operate on the 2.4 GHz frequency and can interfere with your Wi-Fi signal.

Leverage Dual-Band Routers

If your router supports dual-band (2.4 GHz and 5 GHz), you can optimize traffic:

• 2.4 GHz network: Use for thermostats, smart home devices, guest connections

• 5 GHz network: Use for IP phones, conference phones, workstations, and VoIP devices

The 5 GHz band typically offers:

• Less interference

• Faster speeds

• Better performance for real-time applications like VoIP

4. Consider a Router Upgrade

If you've tried all the steps above and continue to experience issues, your router may be outdated or underpowered for reliable VoIP service.

Signs You May Need a New Router

What to Look for in a VoIP-Ready Router

✅ Summary Checklist

📞 Still Having Issues?

If problems persist after trying all steps above, please contact your support representative Networkwith the following information:

• Router make and model

• Firmware version

• Screenshots of your QoS and SIP ALG settings

• Network diagram (if available)

• Description of when issues occur (specific times, frequency)

• Steps already attempted