SIP Trunks in Australia

With the emergence of cloud-based phone systems, the use of SIP trunks in Australia for business is decreasing.

However, they can be a highly effective way to connect older phone-based systems and leverage the power of the Internet for business communication without the need to replace costly infrastructure. 

Below we have outlined the benefits of SIP trunks, why some businesses use them and why they may no longer be required in the future.

What Are SIP Trunks?

SIP (Session Initiation Protocol) trunks are essential for businesses seeking to enhance their telecommunication infrastructure, offering a cost-effective and scalable solution for voice and data communication over the internet.

SIP trunks are virtual phone lines that use the internet to connect a company's private branch exchange (PBX) to the public telephone network.

Most large companies traditionally have used a PBX to manage their phone network, however, as you'll read further below, not all businesses have one or need one.

Unlike traditional phone lines which have been used in the past, SIP trunks transmit voice, video, and other unified communications over a data network, leveraging the power of VoIP (Voice over Internet Protocol) technology.

Why SIP Trunks Are Important for Businesses in Australia

If your business is using a PBX and is looking to implement SIP Trunks, there are some significant benefits, including:

  • Cost Savings: SIP trunks significantly reduce the cost of long-distance and international calls, as well as the expenses associated with maintaining separate voice and data networks.
  • Scalability: SIP trunking allows businesses to easily scale their communication capabilities up or down, accommodating growth or seasonal fluctuations without the need for physical phone lines.
  • Enhanced Reliability: With SIP trunking, businesses benefit from improved call quality and reliability, often with built-in redundancy and failover options to ensure uninterrupted service.
  • Unified Communications: SIP trunks support a range of communication services, including voice, video conferencing, and instant messaging, facilitating seamless collaboration and improved productivity.
  • Flexibility: SIP trunks can integrate with existing PBX systems, enabling businesses to leverage their current investments while transitioning to more modern, internet-based communication solutions.
  • Geographic Independence: Businesses can operate under a unified communication system regardless of their physical location, making it easier to manage remote teams and multiple office locations.

Do cloud-based phone systems require SIP trunks or just the internet? 

Cloud-based phone systems and SIP trunks are both modern telecommunication technologies that utilise the internet for voice communication, but they serve different purposes and have distinct requirements.

Cloud-Based Phone Systems:

  • Internet-Only Requirement: Cloud-based phone systems, also known as hosted PBX or VoIP systems, typically only require a stable internet connection to function. These systems are hosted by a service provider and managed via the cloud, eliminating the need for on-premises hardware.
  • Functionality: They offer a wide range of features such as call routing, voicemail, conferencing, and integration with other cloud-based services like CRM systems. Users can access the phone system from anywhere with an internet connection, using various devices such as IP phones, computers, or mobile devices.
  • Ease of Management: Because the infrastructure is hosted and maintained by the provider, businesses benefit from reduced IT overhead and simplified management.

SIP Trunks:

  • Integration with Existing PBX: SIP trunks are used to connect an existing PBX system (which can be either on-premises or cloud-based) to the internet, enabling VoIP communication. This allows businesses to keep their current PBX infrastructure while transitioning to VoIP.
  • Requirement: In addition to an internet connection, SIP trunks require a compatible PBX system that can handle SIP protocols. Businesses often need SIP-enabled PBX hardware or software.
  • Functionality: SIP trunks provide the ability to make and receive calls over the internet, often with improved call quality and cost savings. They support voice, video, and other unified communication services.

What is the difference between SIP Trunks and Cloud-Based Phone Systems?


  • Infrastructure: Cloud-based phone systems are fully managed and hosted by the provider, requiring no on-site PBX. SIP trunks require an existing PBX system to function.
  • Setup and Maintenance: Cloud-based systems offer simpler setup and minimal maintenance since the provider handles most of the technical aspects. SIP trunks, while reducing costs, might involve more setup and maintenance due to the integration with existing PBX systems.
  • Flexibility and Scalability: Cloud-based systems are inherently scalable and flexible, as businesses can add or remove users and features through the provider’s portal. SIP trunks offer scalability as well, but the extent depends on the capabilities of the existing PBX system.

In summary, if a business opts for a cloud-based phone system, they generally only need a reliable internet connection. In contrast, if they choose to use SIP trunks, they will need both an internet connection and an existing PBX system that supports SIP protocols.

Each solution offers unique advantages, depending on the specific needs and existing infrastructure of the business.


Search SIP Trunks Suppliers in Australia


If you have an existing PBX infrastructure, purchasing an SIP trunking service lets you use your existing PBX equipment to transition into an internet-powered telephone network.

Just like you’d purchase a traditional phone line subscription from a landline provider, SIP trunking is provided by a SIP provider like the ones listed below. 

Still confused? Don't worry, you're not alone!

The good news is the providers below will be happy to talk to you about your requirements and recommend the right approach for your business.