understanding sip vs voip will make choosing a phone system easier

SIP vs VoIP: Everything You Need to Know

Daniel WeissLast updated on October 10, 2023
7 min

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When you’re considering switching to a modern phone system, terms like SIP vs VoIP will surface a lot. What do they mean? Technology is advancing so rapidly, it’s hard to keep up with all the acronyms in the tech world. That’s especially true when you’re talking about modern phone systems.

While you don’t need to understand every term and protocol that has to do with telephone systems, getting acquainted with terms like SIP vs VoIP is a good place to start. You might hear people use them interchangeably. The reality is that they’re not the same thing and they’re not parallel or opposing terms either.

Here’s a guide to understanding the difference between these two basic telephone technologies and the potential each of them has for meeting your business needs. Having a greater understanding of these terms will shed some light on whether a cloud-based phone system is right for you.

Quick links


One way that SIP and VoIP are similar is that they’re both protocols. In technical terms, a protocol is a set of rules that pertains to transmitting data between electronic devices like computers or mobile phones. To successfully send and receive phone messages, there has to be a set of existing rules about how the information is structured and what happens on both sides of the transmission.

SIP is a specific protocol that puts VoIP to work by creating starting and ending points for messages during a call.

VoIP is also a protocol and it simply refers to any internet-based phone service.

Once you understand the protocols, you might be curious about another term that’s related to SIP and VoIP and that’s SIP trunking. SIP trunking is a process that connects your business to a PBX phone system (an office phone system that connects phones to several outside lines and to each other). In the tech world, a trunk refers to the connection between two points.

Now that you’re armed with that information, it’s easier to take a deeper dive into the core differences between SIP and VoIP.

What Is SIP?

The term SIP stands for session initiation protocol. SIP trunking came onto the tech scene in the early 2000s and it’s the protocol that enables VoIP so you can make or receive phone and video calls over the internet. SIP replaces the cable system that’s needed for traditional phone calls. You could think of SIP as being the digital equivalent of a phone line.

The Core Differences of SIP vs VoIP

Since SIP and VoIP aren’t comparable technologies, it’s not possible to do an “apples to apples” comparison. They’re not in competition with each other. SIP is a protocol that’s useful for supporting VoIP protocols.

We’ll outline the differences between them, as well as their pros and cons, to get a clearer understanding of each of them.

SIP – Session Internet Protocol

SIP is used for most VoIP phone systems. It’s a protocol that allows you to place a call or receive one and keep someone on the line for the duration of a phone call or a video call. SIP is also the mechanism that sends out signals every time you get a voicemail or electronic text message.

SIP trunking services are usually hosted and offered by a Unified Communications vendor that offers VoIP services and Unified Communications as a Service (UCaaS). UCaaS includes a non-unified suite of communication tools that includes some combination of cloud apps, traditional software, and a VoIP phone system.

To dissect the differences between SIP and VoIP, we can take a look at some of the pros and cons of SIP.

Pros of SIP

  • Costs less than traditional phone systems-saves on long-distance calls.

  • Serves multiple local lines for offices with several geographical locations.

  • You only pay for the number of lines you need making it easy to scale.

  • Adding and removing channels can be done remotely-eliminates wait times for on-site service calls.

  • Can use phone numbers from any location in the world.

  • Sends calls to mobile devices (failover) if data connectivity is lost.

  • Provides flexibility-you can buy additional features as add-ons.

  • Offers administrative tools that are user-friendly.

  • Easily and seamlessly integrates with cloud applications for a comprehensive communication platform.

  • May offer built-in integrations for common business applications.

  • Can be used to integrate with PRI lines (primary rate interface with up to 23 channels) to create a hybrid phone system.

  • Can consolidate technologies like phone, video, chat, and text for a unified communication system.

  • SIP can be carried over any data network including fiber-optic, copper, and wireless networks.

Because SIP has the capability to enhance basic VoIP capabilities with transmitting messages, chat, videos, and other forms of data over the internet, many businesses prefer it because it helps to increase productivity and save costs.

Affordability is another of the great hallmarks of SIP. The cost to rent SIP lines are typically much lower than traditional PSTN lines where you get charged according to the distance between endpoints.

Cons of SIP

  • SIP requires enough internet bandwidth to support quality service.

  • The quality of SIP varies depending on the provider.

  • The features vary by SIP vendors-not all include full Unified Communications.

  • When using SIP on a public internet service, it could open up quality and security risks, which isn’t a problem with internet service as provided by the same vendor as your SIP carrier. (Note: most phone system platforms provide additional security measures to compensate.)

VoIP-Voice over Internet Protocol

Think of VoIP as any phone service that transmits messages over the internet rather than traditional phone lines. VoIP technology transmits voice packets over the internet instead of transmitting it using public phone company cables (PSTN).

VoIP systems have their own unique set of pros and cons as listed below:

Pros of VoIP

  • Low startup costs.

  • Ongoing costs are steady and predictable.

  • Services are portable and don’t require on-site installation.

  • Even the most basic VoIP service plans include a number of services like caller ID, call waiting, and call forwarding.

  • You might not have to sign a long-term service contract.

  • Your system may be integrated with other business tools.

Cons of VoIP

  • Your internet service provider has to have sufficient bandwidth for you to enjoy call quality of service (QoS).

  • Some basic VoIP services don’t always include the capability for mobile integration or mobile apps.

  • If you have a voice-only VoIP service (without integration capabilities), you won’t have the capability for other communication channels like text, chat, or video.

Choosing the Right Modern Phone Solution for Your Business

Now that you have a good understanding of SIP vs VoIP, how can you apply your new knowledge to choosing the right modern phone solution for your business? If you already have an analog phone (PSTN or traditional phone system) or a PBX system (multiple internal lines and external lines for your office and between offices), you already know the limitations that they have.

Modern phone solutions give you important capabilities beyond being able to call your offices in other areas, your customers, and your peers sitting across the room. If you’re going to invest in a modern phone system, it’s useful to think of it in terms of what your phone service could do for you if it could perform all the functions that you needed it to. What are the business functions that you have on your wish list?

A VoIP system or a cloud-based phone system allows you to take advantage of a wide variety of business apps.

Aircall Features

Do these features by Aircall spark some thoughts about how you could improve your sales and support teams if you had a modern phone system?

Beyond the useful features that you can get with a cloud-based phone system, would you like to have the flexibility to add software integrations to enhance your sales and support teams even further?

While automation is taking over many traditional tasks, phones are still an essential business tool. On the whole, customers are getting more familiar with automated responses, but there are times when someone just needs to speak with a real human. At the same time, customers also want your business to meet them on whichever communication channel they’re currently using. In addition to voice, customers want, and sometimes, expect you to reach them via email, chat, video, or text. Software integrations can make that happen when you have the right phone system in place.

Call Center Integrations

Nearly every business has a CRM system and when you combine it with a cloud-based phone system, you can expand your functionality significantly. The integrations listed in Aircall’s App Marketplace enhance your helpdesk, sales, productivity, quality assurance, customer satisfaction, and much more. If you don’t find the right integration, a developer can customize one using Aircall’s open API.

A VoIP only solution still works reasonably well for many companies, but it doesn’t have all the features that allow you to be truly efficient and effective in today’s marketplace. Consider all that an Aircall cloud-based phone system and software integrations can do to set your company ahead of the competition.

Published on September 11, 2020.

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