What You Will Need
Before starting, confirm you have: an active NBN connection (any technology type), a router with QoS (Quality of Service) support, SIP desk phones or softphone applications, and your VoIP provider account credentials (SIP username, SIP password, SIP server address). If you are using a hosted PBX service, your provider should supply the SIP credentials and any required provisioning instructions.Step 1: Check Your NBN Connection Type
Your NBN connection type determines the baseline quality and reliability you can expect for VoIP. You can find your connection type on your NBN provider's account portal or by checking the NBN address checker at nbnco.com.au.| FTTP (Fibre to the Premises) | FTTC (Fibre to the Curb) | HFC (Hybrid Fibre Coaxial) | FTTN (Fibre to the Node) | FTTB (Fibre to the Building) | Fixed Wireless | Sky Muster Satellite | |
|---|---|---|---|---|---|---|---|
| VoIP Suitability | Excellent | Very good | Good | Variable | Good | Moderate | Poor |
| Notes | Best option. Low, consistent latency. | Consistent for most deployments. | Some peak-hour variation. Generally reliable. | Quality depends on copper run length. Test before committing. | Similar to FTTC in practice. | Latency higher than fibre. Test with your provider. | High latency unsuitable for real-time voice. |
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If your business is on FTTN NBN and experiencing call quality issues, the problem is almost always the copper run between the node and your premises, not your VoIP provider. Before switching providers, test your line quality using your router's diagnostics. See our VoIP call quality guide for diagnostic steps.
Step 2: Test Your Connection Baseline
Before configuring VoIP, measure your connection's latency and packet loss. VoIP requires latency below 150ms and packet loss below 1% for acceptable quality. Use a connection quality test that includes jitter and packet loss metrics. A standard speed test is not sufficient.Tools: ping test to your VoIP provider's SIP server (ask them for the server IP), or use a service like Cloudflare's speed.cloudflare.com which measures latency and jitter. Run the test during your busiest business hours to measure worst-case performance.Step 3: Configure QoS on Your Router
Quality of Service (QoS) settings on your router prioritise voice traffic over other internet traffic. Without QoS, a large file download or video stream from another device on your network can cause noticeable quality degradation during calls.Most business-grade routers (Ubiquiti, Cisco, MikroTik, Netgear Business) support QoS configuration. Consumer-grade routers vary: check your router's manual for 'QoS' or 'traffic prioritisation' settings. The specific configuration depends on your router model, but the general approach is to create a high-priority rule for SIP traffic (UDP port 5060) and your VoIP provider's RTP audio traffic range.
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Ask your hosted PBX provider for their recommended QoS settings and their RTP port range before configuring your router. Most reputable providers publish this information in their setup documentation.
Step 4: Configure Your SIP Phones
If you are using a hosted PBX service, your provider will typically either pre-configure your phones before shipping them, or supply a provisioning URL that auto-configures the phone when it connects to your network. Follow your provider's provisioning guide.If you are configuring phones manually, you will need to enter: SIP server address (provided by your hosted PBX provider), SIP username (your extension or DID number), SIP password, and codec preferences. For Australian NBN connections, G.711 (ulaw/alaw) or G.722 are the recommended codecs. G.722 provides wideband HD audio where supported. Avoid G.729 where possible as it increases latency and degrades under packet loss.Step 5: Test Calls and Verify Quality
After configuration, test inbound and outbound calls. Check: call setup time (should be under 3 seconds), audio quality in both directions, whether calls drop when switching between speakers or on hold, and behaviour during a simultaneous internet-heavy task (simulate by running a speed test during a call).If you are using a hosted PBX system, most providers offer an echo test number or call quality diagnostic you can use to verify your setup before going live.Troubleshooting Common Issues
Common VoIP quality issues on Australian NBN connections and their causes:| Choppy audio / robotic voice | Calls drop after 30 seconds | One-way audio | Calls not connecting | Echo on calls | |
|---|---|---|---|---|---|
| Likely Cause | Packet loss or jitter on NBN connection | NAT/firewall issue with SIP | Firewall blocking RTP audio ports | SIP registration failing | Acoustic echo on handset |
| Fix | Check NBN line quality, enable QoS, check for interference on FTTN copper | Enable SIP ALG workaround or check provider's NAT settings | Open RTP port range in your router firewall (ask provider for their range) | Check SIP credentials, verify firewall is not blocking port 5060 | Use handset in a quieter environment or check headset configuration |
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Most hosted PBX providers have a support portal or knowledge base covering their specific setup requirements. Always check the provider-specific documentation before generic troubleshooting.
How much internet bandwidth do I need for VoIP on NBN?
Each simultaneous VoIP call uses approximately 80-100 kbps of bandwidth (depending on codec). Ten simultaneous calls use less than 1 Mbps. Bandwidth is rarely the limiting factor for VoIP on NBN. Latency and packet loss have far more impact on call quality. Even an NBN12 connection has sufficient bandwidth for multiple simultaneous calls.
Should I disable SIP ALG on my router for VoIP?
This depends on your router model and VoIP provider. SIP ALG (Application Layer Gateway) is a feature intended to help SIP traffic pass through NAT, but many implementations are buggy and actually cause problems. If you are experiencing one-way audio or calls not connecting, disabling SIP ALG is one of the first things to try. Your VoIP provider's setup documentation should specify whether to enable or disable it.
Can I use VoIP with an FTTN NBN connection?
Yes, FTTN NBN can support VoIP. Quality depends on the length and condition of the copper run between the node and your premises. Short copper runs (under 400m) generally perform well. Longer runs or deteriorated copper can introduce latency and packet loss that affects call quality. If you are on FTTN and experiencing issues, contact your NBN provider to check your line statistics.
Do I need a separate internet connection for VoIP?
No. VoIP and regular internet traffic share the same NBN connection. Properly configured QoS settings on your router ensure voice traffic is prioritised. For very high call volumes (20+ concurrent calls) or poor-quality FTTN connections, some businesses choose to maintain a separate connection for voice, but this is unnecessary for most SMBs.
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