VoIP vs SIP Phone Systems: The Key Differences to Know

In recent years, Internet telephony technology has become more reliable and accessible than ever before, allowing businesses of all sizes to enjoy a rich and affordable communication experience.

Both VoIP and SIP provide the foundations for IP technology with ample opportunities and benefits for users to increase their efficiency & productivity whilst saving money. However, how do you tell which technology between VoIP and SIP best works for your business? Below are some of the key aspects of each technology, their similarities, differences and the various ways your business can benefit from each technology.

What is VoIP?

VoIP, short for Voice over Internet Protocol, refers to any technology that allows voice signals to travel over a network which in this case is the Internet. It can be configured using various hardware and software combinations but provided voice messages travel over the Internet, it is VoIP. VoIP technology is rapidly expanding and developing and popular platforms and apps such as Skype are common tools in most small and medium-sized businesses.

What is SIP?

SIP, short for Session Initiation Protocol, is a powerful system of digital rules that allows multiple devices to communicate with each other including sending and receiving multimedia messages. Put simply, SIP is one of the many protocols you can use to implement VoIP. This system is used to set up and terminate multimedia sessions including video and voice. It is this intertwined relationship between the two systems that gets most people confused about VoIP and SIP.

The Relationship between VoIP and SIP

To make it easier to understand, you can think of the relationship between these two technologies as that of websites and HTML. HTML is one of the languages you can use to build a website. Though common, you can also use other languages such as Java. Similarly, VoIP is any method one can use to send voice messages over the internet including enterprise phone services, FaceTime and Skype. SIP, on the other hand, is one of the many protocols being used today although you can use other protocols as well.

Case in point, most enterprise-level phone systems use SIP but Skype does not rely on SIP.

Key Differences between VoIP and SIP

In certain aspects, these two communication protocols differ from each other although with some overlap. Below are some of these differences.


To make a call, VoIP handsets or phones need to be connected to a computer that is turned on and which has an internet connection. On the other hand, SIP phones operate like a regular phone and do not need to be connected to a computer before making a call. However, it does require a modem to send and receive multimedia messages.

Data Handling

VoIP only allows for voice messages. SIP, on the other hand, can handle all forms of media including voice messages. Additionally, SIP systems are processed by individual systems in each user’s system, allowing it to handle more data and traffic than VoIP, which uses one central network. However, this single network system also gives VoIP a stronger security defence.


VoIP is a fundamental technology that uses other protocols such as SIP to allow it to work as it does. On the other hand, SIP is a stand-alone technology that can be used by itself under the VoIP umbrella.

VoIP Vs. SIP – Which is The Best Fit for Your Business?

If you are wondering which technology between VoIP and SIP will serve your business better, you are on the right path moving to the future. However, it is important to note that VoIP vs. SIP is not a direct comparison. Therefore, you should be considering whether voice-only VoIP phone services meet all the needs of your business now and in the near future, or you would be in a better position with a SIP implementation with Unified Communications tools.

As a continuation of this deliberation, UCaaS vs. VoIP is a better comparison than SIP vs. VoIP. If you are already using collaboration technologies and apps which are a part of Unified Communications, then SIP adoption would be the next logical step. However, if you just getting started with the idea of using internet-based phone systems, and you are limited by your budget, VoIP would be a good starting point. With that said, it is also important to remember than SIP enhances the capabilities of VoIP beyond voice messaging including the ability to exchange files, video and other forms of data. As such moving directly to SIP and Unified Communications can offer productivity gains and cost savings even though you will need a bigger initial budget.

Business phone systems can be complex to understand and tell apart – the numerous terminologies and overlapping roles do not help either. This is why we recommend that you talk to a dedicated Voice Services provider offering multiple services including Unified Communications, SIP Connectivity, VoIP, Avaya, Nebula Voice and others. At AdEPT, we are a full-service managed IT service provider offering these and other services. Our team is ready and capable to help you decide which is the best system for you, then assist you with all phases of planning, design, installation, training and then offer proactive maintenance and support for your business communications. Talk to us today to learn more.

Sami Malik

Written by Sami Malik

Marketing Campaigns Manager