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SIP vs. VoIP – What are the differences?

SIP and VoIP are terms that are often used interchangeably in the world of communications, but they’re not the same thing. SIP stands for Session Initiation Protocol, whereas VoIP stands for Voice over Internet Protocol. Both of these technologies have revolutionised the way we communicate, but there are significant differences between them. Let’s explore what SIP and VoIP are, how they work, and what sets them apart from one another.

What is VoIP?

VoIP is a technology that allows voice and multimedia communications to be transmitted over the internet. Instead of using traditional phone lines, VoIP uses IP (internet protocol) networks to transmit voice data in the form of packets. This technology has become increasingly popular in recent years due to its cost-effectiveness and flexibility.

How does VoIP work?

VoIP works by converting analogue voice signals into digital data packets, which can be transmitted over the internet. The data packets are then reassembled at the other end of the call and converted back into an analog signal, which can be heard by the recipient. Some VoIP solutions can offer many features that traditional phone systems do not, such as video conferencing, instant messaging, and integration with other communication tools.

There are two types of VoIP – hosted and non-hosted.

Hosted VoIP

With hosted VoIP, the service provider owns and manages the infrastructure and equipment necessary to run the system. Hosted VoIP systems provide advanced features such as auto-attendants, call forwarding, voicemail to email, conferencing, and other collaboration tools. Hosted VoIP is more affordable and scalable than traditional on-premises phone systems, as the service provider handles maintenance, upgrades, and security.

Non-hosted VoIP

Non-hosted VoIP is an on-premises phone system where the business owns and maintains the equipment and infrastructure to run the system. This requires businesses to purchase and install all the necessary hardware. Not only that, the business will need IT staff to manage and maintain the VoIP system, including upgrades, maintenance, and security. As such, these systems require a higher upfront investment than hosted VoIP systems. However, non-hosted VoIP provides businesses with greater control and customisation over their phone system and is more suitable for larger organisations with more complex communication needs.

VoIP has become increasingly popular over the last decade due to the expansion of broadband infrastructure, and is currently a prescient phenomenon in the UK due to the upcoming PSTN switch off.

What is SIP?

SIP is a protocol (an established set of rules that determine how data is transmitted between different devices in the same network) used to start, modify, and end interactive user sessions involving multimedia elements such as video, voice, and instant messaging. In normal human language, it’s a way of setting up and managing communication sessions over the internet.

How does SIP work?

SIP is used to connect two or more devices, such as phones or computers, to enable them to communicate with each other. It is an application layer protocol that works on top of the internet protocol (IP) and uses the same infrastructure as the internet. This means – in essence – that even though the end user devices are not exactly the same, they can still communicate easily with one another.

SIP trunking vs. VoIP

SIP allows the use of SIP trunking, which forms the backbone of a business’s VoIP setup. Basically a SIP trunk is a virtual phone line – similarly to VoIP, it uses packet switching to connect calls to one another. The main difference between VoIP and SIP trunking is that VoIP only supports voice, whereas SIP trunking allows for voice, video, messaging and fax.

How does SIP trunking work?

As SIP trunks are made up of multiple channels, they are flexible – each channel can connect a single, unique phone call. When a user makes an outbound call through their business’s SIP trunk, it uses one of these channels. This means that multiple people within the business can make calls at the same time. The main advantage of this is that your business saves money on infrastructure – you don’t need to add and pay for a new phone line every time someone joins the business. SIP trunking is a very scalable solution. If you want to know more, check out our beginner’s guide to SIP trunking.

What are the differences between SIP and VoIP?

While SIP and VoIP are often used together, they are not the same thing. SIP is a protocol that is used to initiate, modify, and terminate communication sessions, while VoIP is a technology that enables voice and multimedia communication over the internet. SIP is one of the many protocols that can be used with VoIP. So – what does this mean for you? What are the pros and cons of using VoIP on its own, or using SIP with VoIP?

Just VoIP – the good

  • Cheaper
  • Not on-premises, more agile
  • No tie in to long term contracts

Just VoIP – the bad

  • You need a great internet connection to ensure call quality
  • Only voice, no multimedia
  • No integration with third party apps or software

SIP with VoIP – the good

  • Easily scalable – adding video for instance
  • Can integrate more easily with third party software
  • Can integrate with PRI lines
  • More flexible pricing plans

SIP with VoIP – the bad

  • Needs a really strong internet connection for call quality
  • Quality of service depends on your provider
  • Security issues if used on open internet

So, what’s best for your business?

Clearly, SIP and VoIP can’t be directly compared – not only do they function differently, but there is a crossover as well. Understanding the differences, though, is key to selecting the right solution for your business. Is VoIP alone enough for your business to function effectively, or would you need to implement SIP and VoIP? The SIP and VoIP solution is enhanced – a more flexible Unified Communications solution. Are you confident enough to go it alone, or would you need the support of a trusted partner to ensure the quality of your connections?

Choosing the right partner

Gamma offer the services to suit your business, with our phoneline VoIP system, and our SIP trunking call management. Consider Gamma as your expert partner who can provide bespoke solutions tailored to your business.