Business Telephone Systems

SIP Trunking 

SIP trunking is more cost efficient, reliable and flexible than traditional ISDN.

traditional voice services will soon end

Voice services in the UK are undergoing fundamental changes. The switch-off of traditional voice services is planned for 2025, and BT will stop selling ISDN services this year, which are relied upon by many businesses to make and receive calls.

We encourage our customers to consider switching to SIP trunking way before 2025. It’s flexibility, performance and cost efficiency can significantly improve the way your business operates. 

What is SIP trunking?


Session Internet Protocol (SIP) is a type of Voice over Internet Protocol (VoIP) which refers to calls delivered over the internet. So to keep it simple, SIP trunking essentially enables your voice traffic to be routed over your internet connection. It does this by using a Private Branch Exchange (PBX) to send and receive calls.

SIP trunking replaces your current traditional ISDN phone line. Say goodbye to transmitting voice and data over physical wired connections. SIP trunking is more cost efficient, reliable and flexible. 

A guide to SIP

Is SIP trunking expensive?

The short answer is, no! If you’re considering switching from ISDN, one of the main benefits you’ll notice from SIP is the cheaper day-to-day running costs. Line rental costs can be up to 50% cheaper, as well as significantly cheaper call costs. The savings you make can completely vary depending on your current set-up and usage, we can of course give you an exact figure with our price comparison calculator. Simply get in touch to see how much you can save. 

Does SIP trunking provide good call quality?

It’s a common misconception that SIP trunking requires a lot of bandwidth or struggles to provide a crystal clear call quality. With advancements in technology and connectivity stability, SIP takes up a minimal amount of bandwidth to provide you with a reliable and clear communications channel. 

Is it difficult to setup?

Depending on the complexity of the set up, SIP trunking can be implemented in roughly 5 – 20 days. We will handle the difficult parts and keep you informed throughout the implementation. As standard, Excalibur will minimise downtime and provide a seamless transition for every customer. 

Is SIP the same as VoIP?

SIP is essentially one of many protocols to accomplish VoIP. So to keep it simple, SIP just enables you to transfer voice data via the internet, but if SIP isn’t right for you, there are other ways to achieve VoIP. There’s a lot of acronyms and jargons thrown around the telecoms industry so it’s easy get confused.

What about business continuity?

SIP trunking delivers robust business continuity and can support you throughout emergencies with ease, because calls can be quickly rerouted to an alternative location.

I don’t have a PBX, what can I do?

Not to worry, there’s many other solutions out there which can improve your business telephony. You should consider cloud-hosted telephony as a way of future-proofing and improving your communications. 

And if your organisation is still relying on ISDN for the time being, you’ve still got time before it becomes completely obsolete. But given the proven benefits and cost savings of VoIP and cloud-based telephony, you should consider switching sooner than later!

If you need anymore advice about the benefits of SIP or how to switch to it, our consultants are available to give you free advice via the form above.  

Enquire about SIP