SIP Trunking Australia
Keep Your PBX, Cut Your Call Costs
Connect your existing PBX to our modern VoIP network with SIP trunking from NW Networks. Australian businesses use SIP trunks to replace ageing ISDN and copper lines without throwing out phone hardware that still works. Lower call costs, flexible channels, and genuine local support.
Creative vision
How SIP Trunking Works in Australia — Three Simple Steps
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1
Connect Your Existing PBX
We link your current on-premise PBX system to our VoIP network no need to replace hardware that still works. -
2
Choose Your Channels
Select how many concurrent calls your business needs. Need 5 channels today and 20 next year? No problem — scale at anytime. -
3
Select a Plan
Pick the plan that matches your call volume and feature requirements. Our local support team can walk you through which option fits best.
Real Cost Savings
Businesses moving from ISDN or traditional lines to SIP trunking typically cut their call costs significantly — with predictable monthly pricing and no line rental surprises.
Works With Your Existing PBX
Full compatibility with Yealink, Cisco, Avaya, 3CX, FreePBX and most SIP-compliant systems. Keep the hardware you've already paid for.
Australian-Hosted Network
Your calls run on secure, redundant Australian infrastructure — lower latency, better call quality, and your data stays onshore.
ISDN Replacement Ready
With ISDN being phased out across Australia, SIP trunking is the natural replacement. We manage the whole migration — including number porting with zero disruption.
Why Australian Businesses Choose NW Networks for SIP Trunking
What’s Included in Every SIP Trunk Plan
Every NW Networks SIP trunk is built on secure, Australian-hosted infrastructure — with everything a business needs to modernise its phone system.
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Core Inclusions
- Inbound and outbound calling
- Flexible channel scaling
- Smart call routing and forwarding
- Full VoIP and PBX compatibility (Yealink, Cisco, Avaya, 3CX, and more)
- Secure, encrypted infrastructure
- Australian-hosted platform
02
Optional Add-ons
- Call recording (compliance and quality)
- Advanced analytics and reporting
- Additional local, national, or 1300/1800 numbers
- International calling packs
Common Questions
SIP Trunking Australia — Frequently Asked Questions
01 What is SIP trunking and how does it work?
SIP trunking connects your existing on-premise PBX to a VoIP network over the internet, replacing traditional phone lines like ISDN or copper. Your phones and PBX keep working exactly as before — only the line behind them changes, at a much lower cost.
02 Can SIP trunking replace my ISDN service?
Yes — this is the most common reason Australian businesses switch. With ISDN being phased out across Australia, SIP trunking is the direct replacement, typically at a significantly lower monthly cost. We handle the full migration for you.
03 Will SIP trunking work with my current PBX?
Almost certainly. Our SIP trunks are compatible with all major PBX systems including Yealink, Cisco, Avaya, 3CX, and FreePBX. We confirm compatibility before you commit.
04 How many SIP channels does my business need?
A general rule is one channel per 3–4 staff who actively use the phone. We analyse your real call patterns and recommend the right count — and you can scale up or down anytime.
05 Can we keep our existing phone numbers?
Yes. We manage the full number porting process as part of setup, so your customers keep calling the same numbers with no disruption.
06 Do you provide SIP trunking Australia-wide?
Yes. While we're based in Karratha, WA, our SIP trunking is delivered entirely over the internet — we support businesses across Australia with remote provisioning and ongoing local support.
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Upgrade Your
Business Communication Today
Switch to NW Networks SIP trunking and modernise your communication system without replacing your existing infrastructure. Don’t have a PBX yet? See our business phone systems or fully managed hosted PBX instead.

