Australia's Preferred SIP Trunking Provider

Aatrox Communications is a Locally-owned and operated full-service provider of SIP Trunking solutions.
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SIP Trunk Provider And Your Business

Aatrox Communications SIP trunks are a great addition to your company’s unified communications strategy, and are configured and tested to work with 3CX IP PBX, as well as other popular PBX systems.

By specialising in providing flexible and reliable VoIP services to partners and end users, we have differentiated ourselves by being able to advise how to implement the solution from the ground up.

Get in touch with us today to set up your end-customer or SIP partner account.

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What Is a SIP Trunk System?

SIP, an acronym for session initiation protocol is a signalling protocol, responsible for initiating, maintaining and ending multimedia sessions. Think of it as a digital phone line – where instead of the traditional PSTN (public switched telephone network) lines, you are making calls over the internet.

Simple Rerouting

A SIP phone number isn’t attached to any physical location, therefore allows for simple rerouting to different geographic locations.

SIP channels can be added or removed quickly and easily, making them a very flexible choice for telecommunications.

Cost Effective

Competitive call rates and free calling between remote offices make the change to SIP from traditional telephony a sure way to slash your phone bill.


SIP Trunking allows for the setup of a number of reliability measures including mobile failovers and hosting the SIP trunks across multiple servers.

No Physical Infrastructure

Expanding existing infrastructure no longer needs to be a costly and long process as SIP trunking removes the need for physical phone lines.


SIP Trunking opens up the possibility of fully utilising the extensive features available in unified communications suites.

3cx - Aatrox Communications AU - Sip Trunking Providers Australia

We specialise in connecting traditional phone networks to the internet.

No matter the size of your business, we can get your telecommunications working smarter, faster, and for a better price.

Wondering “what is SIP Trunking used for?” To learn more about our SIP Trunk pricing plans, please contact us at 0383972990.

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Our SIP Trunk Systems

Our SIP Trunk systems are an exceptional addition to any company’s communications strategy. In addition, we have configured and tested all our protocols to work with popular Private Branch Exchange (PBX) systems such as 3CX IP PBX.

Here at Aatrox Communications, we specialise in providing flexible and reliable Voice over Internet Protocol (VoIP) based Session Initiation Protocol (SIP) Trunking systems to our partners, clients and end-users. That means we have the knowledge and experience to advise you on the best way to implement a telephony solution for your business, from the ground up.

SIP trunking basics

SIP Trunking Service Providers

As one of the leading SIP Trunk providers, our SIP Trunks are a great addition to your company’s communications strategy. They’ve been configured and tested to work with popular Private Branch Exchange (PBX) systems such as 3CX IP PBX.

Aatrox Communications specialises in providing flexible and reliable Voice over Internet Protocol (VoIP) SIP Trunk services to our users. We can advise you on the best way to implement a SIP Trunk solution from the ground up. That’s what makes us stand out; as aSIP provider with a SIP Trunk service and SIP Trunk hardware that meets your business needs effectively with a minimal setup fee.

If you’d like to get started and set up an end-customer, SIP partner account, or new trunk for your SIP phone get in touch with us today at 0383972990. Additionally, our support team is available 24/7 via the same number to keep your SIP device functioning.

How Does SIP Trunking Work?

SIP stands for Session Initial Protocol. In its most simple form, this is a type of digital phone line or phone system for inbound and outbound calls.

A SIP provider is offering a signalling protocol, used to connect, maintain, and disconnect phone calls. Unlike a traditional Public Switched Telephone Network (PSTN) line, which uses physical cables to transmit signals, SIP Trunk systems send calls over the Internet.

What makes a SIP Trunk system truly unique is how it allows you to place and receive calls from multiple different phones. All these ingoing or outgoing calls run through the same dedicated internet communications channel – the ‘Trunk’ – which relies on the same SIP to manage calls.

The SIP sends instruction-containing signals between the phones. These can include telling the phones to stream audio between systems or to begin or terminate a connection. SIP providers offer trunk services to give your business greater flexibility.

What Do SIP Trunk Providers Do?

SIP Trunk providers are also known as Internet Telephony Service Providers (ITSPs). They offer digital telecommunication services run over the web. During our SIP Trunking services, we can equip your existing telephone system and phone numbers with SIP Trunks, allowing you to place and receive calls over the internet via IP PBX.

Meet our team at Aatrox communications today and get started on working with your internet telephony service provider.

SIP Trunking Architecture: One SIP Trunk for All Your Connections

You only need a single SIP trunk for all your business telecommunications. A SIP trunk branches into individual channels, which can be easily added or removed to scale capacity once your SIP system has been set up.

Each of your employees will continue to have a unique direct phone number. But, when you use a SIP Trunk service, you’ll no longer have to pay for rentals or individual lines. You only pay for the number of lines you need to use simultaneously, which are shared between all your SIP phone network’s extensions. This is one of the many reasons a SIP is an exceptionally cost-effective method for business telephony.

SIP trunking features

What Is a SIP Channel?

A SIP Channel, also commonly known as a SIP line, is similar to a traditional phone line in that it handles a single incoming or outgoing call at a time.

That’s why all you need to do to increase or decrease your SIP capacity is to add or remove SIP channels as necessary.

What’s more, unlike traditional telephony systems, SIP channels are entirely software-based. That’s why you can add or delete them from your SIP system without needing to install or remove any physical infrastructure for more inbound or outbound calls.

That means that if you want to adjust your telecommunications capacity, you won’t have to schedule a provider to send a technician out, nor will you have to clean out space in your server room – and money from your bank account. Scaling a SIP Trunk system can be done fast, easily, and for little to no additional set-up cost for the SIP trunk services.

Benefits of SIP Trunking

SIP Trunks are far more affordable than traditional phone networks – and much more flexible, too. You can make changes at your leisure, and because calls are routed through your SIP Trunk provider online, you’ll save significant amounts of money on any international calls.

SIP Trunk Systems

SIP Trunking Explained: Here are some of the numerous benefits a SIP Trunk system can offer your business:


Traditional business telephone systems are limited by their capacity.

In contrast, using a SIP saves you the cost, time, and disruption of waiting for physical installations or removals of your SIP Trunk solution.

Because SIP channels are so easy to add to or remove from your network for more or less capacity to handle inbound or outbound calls, they’re an incredibly versatile choice for your business. That’s why they’re an excellent option if your business is rapidly expanding or you’re planning to move into new markets.

Don’t pay for an alternative with a costly setup fee, and choose us as your service provider today and enjoy additional channels.


Because these scaling options work bi-directionally, SIP Trunks offer far greater flexibility than traditional PSTN infrastructure. You won’t have to try to predict demand accurately so you can provision your channels accordingly. Instead, you can adapt to your circumstances as and when they change, saving you money, time, and hassle with SIP trunk services.

You won’t have to pay for unused channels sitting on a line, either. When your business switches to SIP Trunk, you’ll get to enjoy the benefits of considerable cost savings and a flexible, unified media and phone system.

Go Global

Expanding your communications networks worldwide is far easier when you use a SIP Trunk.
SIP Trunk providers often establish relationships with local telecommunications companies in different countries for greater network infrastructure. That means that they can give you the option to route calls over the Internet to your destination country, where they’ll then get charged at local rates.

This will do more than save you money; it means that your business won’t have to worry about managing relationships with local telecom operators everywhere you want to do business. When you use Session Initiation Protocol Trunking services, it’s all taken care of for you.

You’ll be able to set up local numbers in as many places as you please, and make outbound calls and receive calls as efficiently as if you were in the country.

Plus, consumers trust local phone numbers the most. Your business will benefit from appearing as though you were right there, with international numbers, without you ever having to step foot abroad. With Session Initiation Protocol Trunking, long-distance business and entering new markets becomes that much simpler.

SIP Trunking Costs

When you switch from a traditional telephone network to a SIP, you’ll get to benefit from far more competitive call rates. What’s more, since all your calls will be routed through the Internet, you won’t have to worry about shockingly high international call bills.

That’s because SIP providers only route your call back onto the PSTN at an endpoint geographically close to your call’s destination. As a result, it gets charged as a local call. When you use a SIP, your business will be what grows – not your expenses.

When you utilise SIP Trunks, you’ll get to handle calls to and from multiple states and countries at local rates, saving you money. Plus, you won’t have to deal with unwelcome surprises like transit fees and additional long-distance charges.

SIP Trunk providers also have no large-scale physical infrastructure to maintain. This means that they have far lower operating costs than traditional providers – and they can pass these savings right on to their customers.

With their exceptional cost-efficiency, it’s easy to see why Session Initiation Protocol Trunking has become such a popular tool for business telephony. While, with monthly plans at a monthly fee, or pay per line, call, and minute, our flexible plans excel at meeting the needs of your business.

Easier Business Planning

SIP Trunk payment plans usually use a simple Pay-As-You-Go model. These predictable rates mean that they’re a telecommunications option that’s very easy to factor into your business’ finances, making it more straightforward for you to plan your monetary strategies in the future.

What’s more, as all SIP Trunk-based communications are carried out online, it’s easy to set up one of these systems using your existing computer equipment. You won’t have to set up any additional physical infrastructure and will save plenty of office space when you switch to SIP Trunk services with Aatrox Communications, leading VoIP business phone providers.

You’ll no longer need to negotiate the costly, time-consuming process of waiting for a technician and installing new hardware every time you want to expand your telecommunications system. This is a solution that grows with your business, moving forward with you rather than holding you back.

With competitive tier pricing, options like the monthly fee, and no minimum commitment, we ensure that the more your business grows, the less you pay. Experience the same service with lower margins for monthly costs.

Plus, SIP Trunks won’t require regular hardware servicing. They’ll save you recurring revenue on maintenance and assorted costs from your regular provider in the long run. They’re not just an excellent addition for immediate cost-savings – they’re a fantastic long-term switch, too.


Did you know that SIP Trunks can be more reliable than traditional telephony?

Your SIP Trunk provider operates a private, secure network with multiple points of failure, with the public interest in mind, ensuring they can keep going even when the worst strikes. For instance, while natural disasters like bushfires or floods can knock out telephone lines over broad areas, SIP Trunk providers can utilise their multiple points of presence to keep you connected and your business moving.

When you use a SIP Trunk, you will have the option to set up several reliability measures to ensure that your calls run as they should. These can range from tweaks for increased stability to hosting SIP trunks across multiple servers for added security.

Business cloud PBX

Business Continuity

If your business uses a SIP provider, you can operate using softphones.

A softphone is a software-based telephone client that uses your computer’s microphone instead of a handset. That means you won’t even have to purchase expensive, separate desk phones when you use Session Initiation Protocol Trunking! Your employees can handle all incoming or outbound calls they need, right from their computers, further lowering the setup fee.

This also offers your business considerable versatility. With SIP Trunks and softphones, your employees can work anywhere while seamlessly maintaining communication channels and phone numbers familiar to their colleagues and customers alike.

Whether you need to make hasty arrangements to have large numbers of staff working out of the office, such as due to a pandemic; are in the middle of moving locations; or want to explore more remote work options for your staff; you can do so without worrying about the impact or costs on your telephone operations with SIP Trunk solutions.

You can even arrange to forward calls made to desk phone numbers or softphones to your employees’ mobile devices for total flexibility. That’s why SIP Trunks are a fantastic option if you have employees who frequently travel between offices or to your clients.

It’s easy to see why a SIP is a fantastic solution for any business planning to grow – whether in Australia or beyond our borders.

Total Customisability

As a wholly software-based system, SIP offers you unmatched control over nearly every aspect of your communications through our user-friendly customer portal.

Some of the aspects you can configure for your business needs include:

  • Adding / Removing Call Capability to your SIP Trunk system
  • Setting up Call Forwarding
  • Routing calls to different employees, departments, or offices
  • Real-Time Call Traffic Monitoring
  • Configuring Extensions for additional channels across your organisation
  • Enabling / Disabling Calling based on location / price
  • Enabling / Disabling recording of call audio
  • Many SIP Trunk providers make their configuration options available through software-based user interfaces. That means that you can easily automate these changes on your own. It’s just as simple for you to go into this interface and amend them if things change.

Consolidate Your Communications Systems

With the best SIP Trunking providers, you’ll have the option to set up Unified Communications as a Service (UCaaS) systems.

UCaaS systems combine all communications endpoints in your organisation into a single interface. That means that you and your employees can communicate seamlessly with your customers and each other via an internet connection through media, including voice communications, video calling, messaging, conferencing, and even fax!

Establishing UCaaS systems in your organisation will thus result in significant cost savings and greater efficiency. It will also make it easier for your employees to handle all communications from one convenient place.

Enquire With Aatrox Today

Are you on the hunt for an exceptional SIP Trunk provider to streamline your business communications, maximise efficiency, and cut costs?

You’ve come to the right place. Here at Aatrox Communications, we have the knowledge, skills, and experience to transform your enterprise’s telecommunications networks. We can help you keep your communication flowing better and faster with an exceptional SIP Trunk service.

For more information about our SIP Trunk systems or other telecommunications services, please contact us at 0383972990. Get started with Aatrox Communications today, your SIP provider!

Neighbourhood Areas

Melbourne CBD | Fishermans Bend | Karingal, Victoria | Westgarth | NewQuay | Morang | Kerrimuir | Pennydale | Heatherdale | Clayton North | Morang South | Dandenong West | South Belgrave | North Brighton | South Werribee | Jolimont | Auburn, Victoria | Mont Park | Tally Ho

We are proudly preferred partner and advanced certified engineers of 3CX 

3CX Titanium Partner - Sip Trunk and VOIP
3CX Advance Certificate - Aatrox Communications AU


Which PBXs are Aatrox Communications SIP Trunks compatible with?

We’ve invested heavily in ensuring our SIP Trunks are compatible with a range of PBXs, and are certified partners with leading IP PBX, 3CX.

Which phones can I use?

You can connect any SIP-compliant physical phone or softphone to an Aatrox Communications’ SIP trunk.

That said, it is far more common to use a PABX such as 3CX.

The telephone requirements are then set by the PABX.

Can I connect an analog PABX with Aatrox Communications' SIP Trunks?

Definitely – and it’s a great way to get some of the benefits of SIP without the expense of replacing your PABX and handsets.

By using a PSTN Gateway (also called a VoIP Gateway) you can connect a SIP Trunk to an analog PABX.

The PSTN Gateway is a physical piece of hardware that essentially converts the digital SIP voice signal into an analog one that is compatible with your existing PABX.

This can directly replace one or more IDSN2, ISDN10 or ISDN30 connections, and immediately provides significant cost savings.

Can I use Aatrox Communications trunks outside of Australia?

Yes, absolutely.

You can register and use Aatrox Communications’ SIP Trunks from anywhere in the world (some anti-hacking restrictions apply but can be lifted on your account by request).

We have customers in the US, the UK, Europe, New Zealand, India, South East Asia, and the Pacific Islands, all using Aatrox Communications’ SIP Trunks to make and receive calls as though they were in Australia.

This saves money, and gives them additional flexibility.

Will my softphone work (e.g Xlite)?

Yes, any SIP compliant softphone can be registered as an endpoint. 

However as mentioned above, it is far more common to use a PABX such as 3CX. The telephone and softphone requirements are then set by the PABX.

Can I dial 000?

Yes, emergency calls can be made just like on an analog phone line.

However, if your internet connection goes down and you have no redundancy, you will not be able to make any calls (including to 000).

What codecs do Aatrox Communications' SIP trunks support?

  • G.711A (also known as G.711alaw)
  • G.711U (also known as G.711ulaw)
  • G.729
  • G.722
  • G.723
  • G.726-16
  • G.726-32
  • iLBC

Codec selection is performed during call setup as per RFC3265. All calls are transcoded to G.711A for termination on the PSTN.


Learn more about SIP trunk and PBX technologies at our FAQ and Definitions pages

Aatrox Communications is an Australian owned and operated full service SIP Trunk provider. We specialise in connecting the traditional telephony network to the internet for small and large businesses.