If you’ve started to prepare for the PSTN switch-off and are looking to move to a digital based phone system, you’ve likely come across the terms VoIP (Voice over Internet Protocol) and SIP (Session Internet Protocol).

You’ve probably also realised it can be quite confusing because VoIP and SIP are often used interchangeably to talk about calls made over the internet, but they’re not the same.

Knowing the difference is important if you’re planning to move towards an internet based phone network (which all businesses will have to from 2025)

Investing in the wrong thing could cost your business a lot of wasted time and money.

In this blog, we’ll take you through the difference between VoIP and SIP technology to help you make the right decisions for your business.

What is Voice over Internet Protocol (VoIP)?

Voice over Internet Protocol (VoIP) is a collection of technologies that allows phone calls and communication to be made and received over the internet – rather than traditional PSTN fixed phone lines.

Rather than old-fashioned copper wiring, you just need a high-speed internet connection to connect your devices to the system and make calls.

VoIP calls can be made and received via specific VoIP handsets or an app downloaded onto a mobile phone, computer or other mobile devices.

How does VoIP work?

A VoIP phone system allows you to make phone calls through your internet connection by converting the analogue voice signals into digital signals.

VoIP essentially breaks these signals down into data packets, transfers them over the connection and then converts them back on the other end into the evential voice, text or video call.

Because everything is sent over the internet, it allows for more data to be sent and received, unlike PSTN lines, which aren’t capable of handling this type of data-heavy communication.

What is Session Initiation Protocol (SIP)?

Session Initiation Protocol (SIP) enables more varied types of VoIP calls, transmitting voice, text and video data over the network.

It is essentially what starts and ends the VoIP call.

This is often referred to as “SIP trunking”, which is the digital version of the current PSTN and ISDN lines.

SIP trunking is used to connect the virtual environment of VoIP networks so that communication can be made.

This is where some people can get confused between VoIP and SIP.

VoIP is a type of internet-based phone call.

SIP enables the call to happen while also adding video and other communication capability to the VoIP network.

How does SIP work?

SIP/ SIP calling/ SIP trunking is the process of sending call information over a digital line, essentially allowing a VoIP call to happen.

The main benefit of SIP, is that it enables a connection between both local and private telephone systems.

Unlike VoIP (which is primarily used for voice calls over the internet), SIP allows all kinds of digital media and communication to be sent.

Are VoIP and SIP the same thing?

No.

Although VoIP and SIP are often used to mean the same thing, and both refer to calls made over the internet, there are differences.

VoIP is a collection of technologies that allow voice calls to be made over the internet between phones and computers.

SIP is the protocol that enables VoIP calls and creates the platform to send multimedia messages.

Get the most from a VoIP phone system with Communications Plus

With existing PSTN phone lines due to be terminated in 2025, now is the perfect time to switch to a VoIP business phone system.

Using VoIP, you can create more flexibility and freedom for employees to manage calls from anywhere, on any device, while maintaining control over your business’ communication network.

At Communications Plus, we can provide the software and hardware you need to create a fully connected and efficient VoIP phone system in your business.

Browse our products online or get in touch to get more information.