Prepping for VoIP: What to Review in Your Network Setup First

Switching to a VoIP phone system can cut costs, boost flexibility, and make business communication easier. But before you make the leap, there’s one crucial step you shouldn't overlook: your network setup. Poor network performance can lead to dropped calls, voice lag, or even system downtime. This article breaks down exactly what Australian businesses should review in their network setup before rolling out VoIP — so your new system works the way it should, from day one.

Table of Contents

1. Understanding the Role of Your Network in VoIP
2. Internet Connection: Speed and Reliability
3. Network Hardware: Routers, Switches, and Firewalls
4. Quality of Service (QoS) Configuration
5. Bandwidth Requirements: Calculating for VoIP
6. Network Segmentation for Voice Traffic
7. Security Considerations for VoIP
8. Testing Your Network Before Go-Live
9. Final Checklist Before Deployment
10. Conclusion & Next Steps

1. Understanding the Role of Your Network in VoIP
VoIP relies entirely on your internet connection. Unlike traditional phone lines, VoIP converts voice into digital data and sends it over your existing network. That means your call quality is only as good as your network's performance. For most Australian businesses, especially those using cloud-based services, it’s worth treating VoIP as part of your overall IT ecosystem — not a standalone tool.

2. Internet Connection: Speed and Reliability
Check Your Upload and Download Speeds
VoIP doesn’t use as much data as video streaming or large file transfers, but it does require a consistent, stable connection. A typical VoIP call uses around 100 kbps per line, so if you’re running 20 simultaneous calls, that’s around 2 Mbps of dedicated, uninterrupted bandwidth — and that’s just for voice.

Tip: Run a speed test during peak hours to see your real-world speeds.
Consider Business-Grade Internet
If you’re still on a basic NBN residential plan, it may be time to upgrade. Many Australian ISPs offer business NBN or fibre connections that come with higher SLAs, static IPs, and faster upload speeds — all of which benefit VoIP.

3. Network Hardware: Routers, Switches, and Firewalls
Your hardware plays a big part in VoIP performance.

• Router: Ensure it supports SIP ALG settings or allow disabling it — SIP ALG can interfere with VoIP traffic.
• Switches: Managed switches are preferable. They allow for VLAN configuration, which improves traffic management.
• Firewall: Make sure it won’t block or throttle SIP ports (typically UDP ports 5060 and 5061).

Australian Example: A Brisbane-based law firm upgraded to a business-grade router with proper QoS settings and noticed immediate improvement in call clarity across all five office locations.

4. Quality of Service (QoS) Configuration
Quality of Service (QoS) lets you prioritise voice traffic over everything else on your network. This means even if someone is downloading large files or using Zoom, your VoIP calls stay crisp and clear.
Key QoS Tips:

• Prioritise UDP port 5060-5061 and RTP ports 10000–20000.
• Set higher priority for VoIP devices in your router or switch settings.
• Test changes after configuration to confirm impact.

5. Bandwidth Requirements: Calculating for VoIP
A common mistake is underestimating bandwidth needs. Here's a quick guide:
Number of UsersMinimum Recommended Bandwidth (Up/Down)50.5 Mbps
101 Mbps
252.5 Mbps
50+5 Mbps or higher (fibre recommended)
Remember: This is just for VoIP. Factor in your other internet usage too.

6. Network Segmentation for Voice Traffic
Segmenting your voice traffic using VLANs (Virtual LANs) helps isolate it from your data traffic. This reduces latency and avoids interference.

• Set up a separate VLAN for VoIP devices.
• Assign different IP ranges for voice and data.
• Use managed switches to control traffic flow.

Australian Use Case: A Melbourne-based call centre with 40 agents avoided voice dropouts by separating voice traffic from their CRM and email servers using VLANs.

7. Security Considerations for VoIP
VoIP systems are vulnerable to the same threats as other online services — including phishing, toll fraud, and DDoS attacks.
Key Security Tips:

• Use strong passwords and regularly update credentials.
• Implement firewalls that support VoIP protocols securely.
• Choose VoIP providers that offer encrypted call options and SIP TLS/SRTP support.

8. Testing Your Network Before Go-Live
Before switching everyone over, run controlled tests.

• Set up a few test handsets in a live environment.
• Monitor jitter, packet loss, and latency.
• Use VoIP monitoring tools to simulate real-time traffic.

Tip: Tools like PingPlotter or VoIP Spear help identify weak spots before they affect live users.

9. Final Checklist Before Deployment
Here’s a quick checklist to make sure you’re VoIP-ready:
✅ Business-grade internet connection
✅ Router with QoS and SIP-friendly settings
✅ Managed switches with VLAN support
✅ Adequate bandwidth based on users
✅ VoIP traffic prioritised
✅ Firewalls configured correctly
✅ Security protocols enabled
✅ Pilot testing completed

10. Conclusion & Next Steps
​Getting your network ready for VoIP isn't just about speed — it's about consistency, control, and prioritisation. By reviewing your internet connection, upgrading key hardware, setting up QoS and VLANs, and ensuring security, you’re laying the foundation for a reliable, high-quality phone system that supports your team and impresses your clients.
Thinking about upgrading your phone system?
Contact us to speak with our Australian-based VoIP experts. We’ll help you assess your current setup and design a VoIP solution that works for your business.