Let’s get under the trunk of SIP Trunking
If you’ve been exploring the telecoms options that are available to your business, you’ve probably come across the term SIP trunking. There’s a good chance that you’re aware that December 2025 is hugely significant when it comes to telecoms. It is then that the Public Switched Telephone Network (PSTN) is to be switched off. This will lead to all calls being based online with the existing copper network and ISDN lines being redundant.
The upcoming changes have led to more business owners and IT professionals mulling over the question “ What is SIP trunking and how does it work?”. What may have once been an area of curiosity has since transformed into one that is vital to understand.
If you’re looking for an understanding of “ What is SIP trunking?” then we’re here to help. Read on to learn how trunking is set to play an essential role as everyone is poised to switch from ISDN.
So, what is SIP trunking exactly?
The first part of understanding SIP trunking is to understand what SIP refers to. It stands for Session Initiation Protocol and, in basic terms, it is a way that end connections can be made that allow for the transfer of data and voices over the internet. Essentially, it can be seen as one of the varying types of protocol that can be used for Voice over Internet Protocol (VoIP). It allows voice signals to be converted into data which is then delivered to, and decoded for, the end-user.
When looking at the question “What is SIP trunking?”, the next element is trunking. Now, when referring to traditional phone systems, the term would relate to a bundle of lines that are shared by users. In the new approach to telephony, trunking is a virtual link, made using the internet, between your Private Branch Exchange (PBX) and the PSTN.
Modern businesses will often now have a PBX that is capable of supporting SIP to transfer data. With the end of ISDN in sight, SIP trunking is now seen as the standard approach to connecting business phone networks over the internet.
Which businesses should be utilising SIP trunking?
If you’re running a business that is making and receiving calls then SIP trunking is for you. Okay, so that may sound a little simplistic as an answer but the reality is that when you’ve got all of the answers to “What is SIP trunking and how does it work?”, you’ll soon realise that the benefits apply to businesses of all sizes and in all industries.
If you’re completely new to the concept of SIP trunking, there is first a decision that needs to be made before you can make the move away from an analogue PBX: you need to choose between an on-premise solution or one that is 100% cloud hosted.
It’s worth pointing out that if you opt for an on-premise setup, you’re going to need someone within your organisation that can manage and maintain your system. The reality is also that an on-premise solution will typically prove to be expensive, at least in the short term.
SIP trunking vs. VoIP vs. Teams telephony
When looking at the question “What is SIP trunking?” it’s incredibly easy to get confused. Even with a lack of experience, it’s fair to say that most people have heard of VoIP and Teams. When SIP trunking is thrown into the mix there it can become difficult to know how this fits into the mix. To understand this, you need to consider PBX, VoIP, and SIP trunking and what they all mean.
A PBX can be seen as a controller for your phone system. With it, you can set up phone numbers, control how calls are handled and set users. If you have a hosted PBX this means that it is cloud-based. Now VoIP is simply a method of sending your voice over the internet. It can be considered as being the phone service that all other services are attached to. SIP trunking is the virtual cable that connects your PBX and VoIP.
In essence, Teams acts as your hosted PBX. The calling plans on Teams are via VoIP so this is what is powering your calls. Your SIP trunking is used so that you can use your chosen provider rather than the default service offered by Microsoft. So, PBX, Teams, and SIP trunking are not comparable: they all work together.
What are the benefits of SIP trunking?
With a greater understanding of the question of “What is SIP trunking and how does it work?” it soon becomes apparent that there are a whole host of benefits that businesses can tap into. These include:
- Reduced cost – Traditional forms of telephony have often seen businesses paying over the odds. With SIP trunking, you can be sure that you’re charged only for what you use and that savings can be as much as 50%
- Flexibility – With a traditional phone line your phone number is restricted to your location. With SIP trunking, no matter where you are you can have a number that suits your needs
- Ready for the future – As we’ve seen, 2025 will introduce significant change. With communication being an essential part of all business, SIP trunking means that you’ll continue with no interruptions
- Unified communications – It could be that your business uses a mixture of phone calls, emails, instant messages or conferencing. With SIP trunking your can link these communication methods so that they become a unified solution
Choosing a SIP trunk provider
Once you’ve made the decision that SIP trunking is the way forward, you’ll need to decide which provider you’re going to use. When making this decision, just some of the factors that you’ll need to consider are:
- Price
- Security
- Uptime
At Landall, we tick all of the boxes when it comes to being a great SIP trunk provider. If you want to know more then all that you need to do is get in touch.
