Most businesses need more than just voice calls from their communication providers. A majority of business interactions are now conducted through email, SMS text, video conferencing, and cloud-based chat platforms rather than traditional telephone conversations.

The internet has made internet-based communication a standard method for business communication. You’ve probably encountered terms like SIP and VoIP while researching business phone systems. It may be confusing to know what these terms mean and which option is right for you.

You will learn about SIP vs. VoIP including their pros and cons and how to pick the solution that is right for you through the following guide.

What is SIP and How does it work?

What is SIP and How does it work

SIP trunking is a technology that allows users to call any number on the PSTN and the internet by simply connecting to their IP PBX system. Session Initiation Protocol (SIP) is a protocol that governs the start and end of live data transfers, such as VoIP. 

SIP trunking also uses the SIP protocols. The SIP provider connects your existing PBX (Private Branch Exchange) telephone system to the internet using an SIP trunk, which is like a virtual analog telephone line. SIP trunking can grow or shrink in size to handle more or fewer concurrent calls.

Traditionally, PSTN (Public Switched Telephone Network) circuits had a fixed ceiling. You could only have 24 concurrent calls on your circuit. It would get a busy signal when calling #25.

Using the SIP protocol, SIP trunking services can also transfer multimedia data to facilitate video conferences and communication.

Therefore, VoIP is a technology that uses the SIP protocol to allow calls and multimedia to be transmitted over the Internet. To achieve similar results to VoIP, SIP trunking connects your business’s PBX telephone system with the telephone network (PSTN) using the SIP protocol.

What is VoIP and How does it work?

What is VoIP and How does it work

A VoIP service (voice-over-internet protocol) allows users to make phone calls over the internet.

VoIP transmits voice packets wirelessly or over Ethernet, unlike traditional phone systems using a public-switched telephone network (PSTN).

Compared to traditional landline phone systems, VoIP relies on the internet for making calls.

An internet-connected device like a computer or mobile phone makes a VoIP call by capturing audio frequencies and making them into data packets, which are then sent through a local area network (LAN) router, then through the VoIP gateway or session border controller (SBC). Next, the SBC chooses whether to send the data over the PSTN, over a local wide-area network, or over the internet to another VoIP user.

As well as SIP trunking – through an onsite IP PBX – you can also enable VoIP by utilizing a hosted PBX (private branch exchange) system, where a VoIP provider maintains your phone system for you.

Pros and Cons of using SIP vs. VoIP

Pros and Cons of using SIP vs. VoIP

You can use the following breakdown to determine which option is a better fit for your situation if pros/cons are important to you.

Pros of SIP

Communications SaaS Integrations

A number of SIP trunk providers–such as Twilio and Bandwidth–offer voice solutions that integrate with your UCaaS, CCaaS, unified communications, and CPaaS platforms. Within your UCaaS app dashboard or from an agent’s contact center interface, you can access SIP-supported VoIP calling.


SIP trunks give you more control over business features. If you don’t need certain features, you can disable them and request upgrades. A SIP trunk only delivers voice to your phone system, so it is dependent on your hardware and software.

Add-on Features

Call recording, number porting, and call analytics are all available as add-on features in many SIP pricing plans.

VoIP phones with toll-free numbers allow your customers to make and receive calls at no cost, regardless of where they call from. SIP providers offer toll-free and local numbers across the United States, allowing businesses to establish a global presence

HD Voice Quality

High-quality codec software, which detects and transmits a variety of audio frequencies, is used by SIP providers. SIP calls offer much better quality than traditional landlines.

Unlimited Domestic Calling

A typical SIP trunking provider offers monthly subscription-based pricing with unlimited calling within the United States and Canada. You will probably save money with SIP trunking, compared to your previous landline provider, if you have high inbound and outbound call volumes.

No Additional Hardware with Virtual SIP

Virtual SIP trunking does not require any additional hardware–only an IP PBX system and an internet connection. You don’t need to purchase and install any new phone lines or buy any handsets–your agents can make calls using softphone functionality from their computers or mobile devices.

Cons of SIP


If you don’t use firewalls to protect your network, SIP trunking presents a security risk since it transmits audio over data packets, which hackers can intercept.

With proper configuration of your LAN routers, WAN servers, and IP PBX, security will not be a problem.

Requires Sufficient Network Bandwidth

VoIP and SIP consume a lot of bandwidth. Switching from landline to SIP voice calls places much higher bandwidth demands on your network and router. You may need a second or more powerful router to support SIP, especially if you have a live call center with many agents making calls at once.

Harder to use

SIP trunking systems are also more difficult to use due to their difficult setup process. Your employees will need to be trained on new processes and given specific devices, which can consume valuable company time.

Fewer Built-in Features Than VoIP

When compared to VoIP, SIP trunking typically offers fewer features.

Many VoIP solutions offer call queueing, analytics, routing features like auto attendants and ring groups, multimedia messaging, video calls, team chat, advanced voicemail, and more. On the other hand, SIP trunking plans usually include only a few features, such as call analytics, local and toll-free numbers, and sometimes call recording.

SIP trunking plans are generally more expensive than VoIP phone systems.

Pros of VoIP

Easy Setup and Maintenance

You can easily set up and maintain VoIP phone systems, especially if you opt for a hosted VoIP PBX service.

With a hosted PBX system, you no longer need to set up or maintain any onsite IP PBX or SIP trunk. VoIP providers, including Dialaxy, KrispCall, RingCentral, and Nextiva, include all software and hardware upgrades with their cloud-hosted PBX systems.

You can set up your cloud-hosted VoIP solution in minutes. Simply choose a subscription from your provider’s website, and you can begin making calls right away. Softphones are available from most VoIP providers, so you don’t need any additional hardware to make calls.


Your business can save a lot of money by using VoIP-based services. SIP trunk systems are often expensive unless you already own the expensive equipment. Furthermore, you’ll need to hire a qualified professional to set it all up and maintain it – all costs that accumulate over time.

VoIP solutions don’t require high upfront costs—only a monthly subscription. VoIP services usually include local, toll-free, and international phone numbers; software updates are usually included in the price.


Unlike legacy PBX landline systems, VoIP phone systems can be scaled more easily by adding and removing users and managing phone numbers thanks to wireless connections. Due to this, VoIP eliminates PRIs- physical copper telephone lines that connect landlines to the PSTN.

Due to the need to purchase and install new copper wires into your onsite PBX system, landline PRIs (primary rate interfaces) make scaling difficult and expensive. By contrast, you can scale a VoIP phone system virtually, adding users and numbers as needed.

With VoIP providers, you can purchase DID numbers and cancel them with just a few clicks, adding or removing users within minutes. VoIP allows you to scale your workforce much more easily than legacy PBX.

Advanced Features

A number of VoIP providers – including Dialaxy and Krispcall – offer VoIP service alongside advanced telephone features, like voicemail, routing, and queueing.

Most VoIP plans include self-service IVR menus, call queues, ring groups, skills-based routing, custom routing orders, voicemail transcription, and more.

Visual voicemail

While a SIP trunking service can support these features, this typically requires you to seek out third-party UCaaS vendors that offer them. Subscribing to a VoIP pricing plan, with all phone-systems features built into the software, makes it much easier and more affordable to access a wide variety of phone system features.

Work from anywhere

Traditional desk phones have limited functionality and mobility. Leaving your desk means leaving your phone behind. All of that is changing with VoIP communications.

VoIP providers allow you to work from anywhere with your team. From wherever they are, they can log in on a web browser using their computer or mobile device with their number or download their provider’s business phone app.

Security and encryption

In spite of the fact that internet communication may seem insecure, it is actually quite secure. VoIP telecommunications are extremely secure since VoIP providers are able to implement advanced security features and encryption tools that are not available for analog phones. Moreover, they can ensure that all data is encrypted during transit and at rest. Additionally, this includes all other aspects of your system, such as user data, chats, analytics, etc.

Third-Party App Integrations

You can integrate VoIP phone systems with CRM systems, UCaaS platforms, collaboration apps, and calendaring apps much more easily.

Agent and supervisor dashboards are typically designed to integrate tools across apps into one interface, enabling agents to collaborate, serve customers, and gather relevant background information.

Cons of VoIP

Requires Internet Connection

VoIP is one of the most cost-effective, flexible, and scalable types of communication, but VoIP does require an internet connection, which can prove problematic if you lose your internet connection.

VoIP calls will not be possible if your building’s power goes out–or if your internet provider goes down.

Recurring costs

Certain VoIP features may incur additional costs, such as adding more local numbers or toll-free numbers, which are not always included with subscriptions. If you’re choosing a VoIP service, make sure all the features you want are included in the monthly fee and that there are no hidden costs.

Even if you don’t use some VoIP features, such as business fax, video conferencing, and call analytics, you must pay for them because they have valuable business uses.

May Waste Pre-Existing Onsite PBX

When you sign up with a hosted VoIP provider, the PBX hardware you already have in your office will go to waste. PBXs are managed by hosted VoIP providers.

Even though VoIP setup may be costly at first, it typically ends up saving medium-sized businesses a few thousand dollars per month, so switching to hosted VoIP technology is a wise investment.


In conclusion, both SIP and VoIP offer valuable communication solutions for businesses. While SIP provides more flexibility and interoperability, VoIP offers cost-effectiveness and simplicity.

Ultimately, the choice between SIP and VoIP depends on your specific business needs and priorities. Consider factors such as budget, scalability, and integration requirements before making a decision. Consult with an IT expert or service provider to determine the best option for your unique circumstances.


What is better SIP or VoIP?

Choosing between SIP and VoIP depends on the specific requirements. SIP is a protocol for establishing real-time communications, while VoIP consists of a range of voice communication technologies. The decision must be made in accordance with individual requirements and existing infrastructure.

Can you have VoIP without SIP?

VoIP can function without SIP if you only need voice communication. SIP technology is required if you want to deploy VoIP and enjoy multimedia communications.

Does SIP need internet?

Yes, SIP (Session Initiation Protocol) usually relies on the Internet to communicate. SIP is a signalling protocol used to initiate, maintain, modify, and terminate real-time sessions involving video, voice, messaging, and other communications applications. As part of the Internet Protocol suite, it operates at the application layer.

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