What Is VoIP and How Does It Work?

What is VoIP?

Voice over Internet Protocol (VoIP) lets you make calls using the internet, transporting audio data from end to end. You’ve probably used VoIP before with top messaging apps such as WhatsApp, Discord, FaceTime, and Microsoft Teams, all of which rely on VoIP technology to work.

VoIP has changed communication from the days of landlines, making it more accessible, cost-effective, and convenient. It has allowed businesses to establish overseas call centers and conduct seamless conference calls with integrated screen sharing. For individuals, VoIP provides an affordable way to connect with people worldwide, eliminating the high costs associated with traditional telecom providers.

How does VoIP work?

VoIP works by taking your voice, converting it into digital signals, breaking that data into small packets that can be routed across the internet, then sending those packets and reassembling them at their destination. This happens on both ends of the call simultaneously, allowing you to talk with someone in real-time over the internet.

VoIP converts your voice into digital packets that travel over the internet and are reassembled instantly for real-time calls.

There are a few things you need for a VoIP system to work properly. Here’s a short explanation for each distinct part of a working VoIP telephony system:

1. The right kind of network. VoIP relies on TCP/IP networks, such as the internet, to establish connections, then typically switches to UDP to transport voice data. The network connection needs to be stable, have minimal jitter, and provide enough bandwidth (typically a minimum of 100 kbps). If the internet isn’t working, VoIP won’t work.

2. The right protocols. VoIP depends on two main categories of protocols: A signaling protocol, such as SIP (Session Initiation Protocol), to set up and tear down (end) calls. You also need a media protocol, such as RTP (Real-time Transport Protocol), to carry the voice data.

3. The right hardware and software. You need a system that can take your voice input, process it, and send it over a network. This could be a VoIP-capable desk phone or software like Teams or WhatsApp. These systems use the appropriate codecs (coder-decoders), such as G.711 or Opus, which convert your analog voice into digital data, compress it for transmission, and then reverse the process at the receiving end.

4. A VoIP service. All this communication wouldn’t be possible without a VoIP service to route calls properly. Modern devices frequently move between different networks, change IP addresses, and may not be switched on or be online all the time. VoIP services track who is online and what address their device is using, allowing calls to be routed correctly.

What is the difference between VoIP and landline phones?

The main difference between VoIP and landline phones is how calls are transmitted. Traditional landline phones use the PSTN (Public Switched Telephone Network), which requires a dedicated circuit-switched connection for the duration of the call. On the other hand, VoIP uses packet-switched IP networks, where voice data is broken into packets that may take different routes to reach their destination.

However, that’s not the only difference. Here are a few key distinctions between landlines and VoIP systems:

There are also some benefits and drawbacks to using VoIP. Below are some reasons why VoIP is so widely used, and some cons that come with it.

Pros of VoIP

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  Video calling and interaction. Enables interactive video calls with features like collaborative whiteboards, remote control, file transfers, and screen sharing.

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  Encryption. Each stage of communication can be encrypted, from the signaling and media transport protocols to the entire end-to-end call. You can also route calls through a VPN connection for added privacy.

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  Reduced cost. Since VoIP services use existing internet infrastructure, the cost of making a call is often included in your internet plan. This makes it an inexpensive, or even free, way to communicate.

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  Mobility. Your VoIP device can seamlessly transition between networks, obtaining a new IP address with each switch. Calls work over Wi-Fi, 4G, 5G, and any other internet connection, so your calls remain uninterrupted.

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  Redundancy. Due to the nature of packet-switched networks, if one route fails for whatever reason during a VoIP call, packets are quickly routed using a different path to the destination. With a landline connection, if the circuit is broken, the call will drop out.

Cons of VoIP

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  Quality depends on your network connection. If your internet connection is unstable or slow, your call quality will suffer. This differs from a landline, where dedicated circuitry is used, ensuring you have stable and predictable call quality.

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  Emergency calls can become more complicated. Because VoIP calls rely on an internet connection and external power, emergency services may be unable to pinpoint your exact location, and the service may become unavailable during a power outage.

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  Vulnerability to cyberattacks. Attackers don’t need physical access to devices or telecommunications wiring, increasing vulnerability to remote threats like a DDoS (Distributed Denial of Service) attack.

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  Vulnerability to social engineering attacks. Social engineering attacks, like phishing, can be highly convincing. By leveraging spoofing techniques, attackers can make vishing calls appear genuine, often imitating trusted phone numbers to deceive their targets’ caller IDs.

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  Limited cross-platform compatibility. Most VoIP apps only work within their own platforms — you can’t make a Discord call from WhatsApp or a Microsoft Teams call from FaceTime. Landlines don’t have this limitation, allowing any landline to call another, regardless of the phone manufacturer.

How much does VoIP cost?

The costs associated with VoIP depend on the subscription provider and plan, your internet or data plan, the hardware you’re using, and whether you’re using an app or call plan.

When evaluating the cost of VoIP, here are the key areas to look:

• Subscription plans. A dedicated VoIP plan for your home from a VoIP service provider typically starts at around $7 per month, and for small businesses it averages around $15 to $35 per month per user. Depending on the plan, you can call from a dedicated physical VoIP handset, a smartphone app, a desktop app, or a web browser.

• Call rates. Using VoIP is considerably cheaper for international calls than traditional phone services. Calls made within the same platform, like from one WhatsApp user to another, are usually free and don’t cost anything extra for long distances. For calls to landlines or mobile numbers, many services offer options to buy credit or pay as you go. For example, Viber Out has cheap international call rates, with calls to Canada starting as low as 0.9¢ per minute.

• Hardware. VoIP phones tend to cost between $20 and $150, which is relatively cheap compared to mobile phones. If you want to use a computer for calls, you could consider a softphone, which is software that lets you make VoIP calls. This lets you make use of existing hardware, and you may just need to buy peripherals, like a headset.

• Internet usage. While many factors contribute to the cost of an internet plan, the average per household is $67 per month for fiber. Businesses can expect to pay anything from $50 into the thousands, depending on the size. Of course, most individuals and businesses will already have a connection set up and use it for other purposes besides VoIP.

Is VoIP the right choice for me?

The advantages of VoIP include lower costs, increased flexibility, more features, and higher scalability. The disadvantages include dependency on the internet, reduced emergency calling capabilities, and possible hardware costs. You need to weigh the pros and cons when deciding if VoIP is right for you.

For example, some areas simply can’t get reliable internet, or your call volume may not warrant a new setup. There are several reasons why VoIP could be wrong, or right, for you. But if you do want to switch, here’s how:

How to switch to VoIP

We’ll show you how to switch to VoIP from a landline setup. Switching to VoIP for your home or small business can involve several different setup options, but the steps below outline a typical path:

1. Ensure your internet connection is stable. Before making the switch, you should assess whether your connection can reliably support VoIP call quality. A stable connection with sufficient bandwidth and low latency is essential.

2. Select a VoIP provider. VoIP providers offer different pricing, features, and requirements. Shop around and find the best fit for your situation. For example, if you’re a home user, you might only need a single phone number and a softphone with a headset, rather than multiple numbers or dedicated desk phones.

3. Port existing numbers. If you want to keep your current phone number, number porting may allow you to transfer it to your new VoIP service. Keep in mind not to cancel your existing plan until your number is fully ported over, or else you might lose the number for good.

4. Set up your VoIP devices and networking equipment. Now you can begin to configure your equipment, such as hardphones. This is also the stage to optimize your network by enabling features such as QoS (Quality of Service) to prioritize voice traffic, and VLANs for improved security and ease of management.

5. Undertake any training necessary. A VoIP system is only effective if users know how to use it. Take time to familiarize yourself with the new system, or, in a business environment, provide training to employees who will be using the VoIP service.

What equipment do you need to set up VoIP?

To set up VoIP you will need at the very least an active internet connection, a capable router that’s been configured properly, and a compatible device such as a smartphone, computer, or VoIP phone. You may also need or want peripherals such as headsets and Ethernet switches for wired desk phones.

If you’re part of a larger business, you may also require a PBX (Private Branch Exchange). This system handles extensions, call routing, call queues, and IVR menus (for example, “Press 1 for support. Press 2 for sales., etc.”) In modern VoIP setups, the PBX is commonly hosted in the cloud, rather than deployed as on-site hardware.

Protect the privacy of your VoIP calls with Avast

VoIP has made communications simpler, less costly, and available to anyone with a smartphone or compatible device. When communicating online, privacy is critical, and tools such as Avast SecureLine VPN help encrypt your in-transit voice data and other information. Make your privacy a priority, and try a VPN with bank-grade encryption today.