Best VoIP Services
Based on In-Depth Reviews

VoIP phone service is now more popular than ever thanks to its cost benefits over traditional telephony, the emergence of new technologies, and the rising trend of workforce mobility. This is compounded by government & private-led investments to develop wireless communications infrastructure and increased adoption of cloud-based services. Overall, the industry is estimated to grow from its 20 billion USD market size in 2018 to approximately 55 billion USD by 2025.

What Is VoIP? How Does It Work?

The easiest way to understand what VoIP is and how it works is by comparing it to its older, analog counterpart: POTS or plain old telephone service. And yes, that’s exactly what it means. A traditional landline phone service built on copper wires that runs through your home to transmit voice calls. 

POTS is also known as the PSTN, or Public Switched Telephone Network, an interconnected network of copper and fiber-optic wires system consisting of a telephone instrument located at the end-users’ premises. These are connected by two wires to a “telephone exchange;” subscribers are not directly connected.

VoIP is something entirely different. Short for Voice over Internet Protocol, VoIP enables users to make voice calls using a broadband Internet connection instead of a regular phone line. Rich Tehrani, CEO of TMCnet, explained to us that VoIP “differs from the traditional telephone lines it replaced by converting voice calls into a series of packets and then sending them over a network where they were converted back from packets to an audio stream.” He likened the process to encoding an MP3 from a live broadcast and decoding it back when you play the MP3.

By converting your voice into a digital signal, VoIP allows users to make a call directly from a computer, a VoIP phone, or other data-driven devices. Because of this, it is occasionally referred to as IP telephony, internet telephony, broadband telephony, and broadband phone service as well.

“It's not unlike what a CD does,” said Andrew Prokop, who has been heavily involved with SIP and VoIP technologies for more than two decades. “A CD converts analog sound to digital and then puts it in the CD disk as bits and bytes as 16-bit encoding, or something like that. And it's just a whole series of those 16-bit numbers that represent some portion of the sound. The more portions you have, the better the sound [quality] is because you're going to sample more of the waveform. So, the waveform is moving along and you're sampling it at all these points to try and get the correct sound.”

Prokop also compared it to record albums, which have grooves that vibrate the needle of a record player to recreate a waveform. Instead, in a digital world with VoIP, you're converting the waveform to bits and bytes.

More specifically, VoIP is not one, but a group of technologies and methodologies that can deliver voice communications in a variety of ways, including over-the-internet and enterprise local area networks or wide area networks. VoIP endpoints, for example, involve dedicated desktop VoIP phones, softphone applications running on PCs and mobile devices, and WebRTC-enabled browsers.

VoIP Protocols

A protocol, or communication protocol, is a set of rules that allows the interaction of two or more devices on a network, enabling the flow of information back and forth. The Internet protocol (IP), for example, is what connects us to individual networks, thus creating the vast web of interconnected networks that is the Internet.

VoIP uses Internet protocol as its method of transportation. Calls are routed through the Internet instead of through regular PSTN lines. However, Internet protocol is not enough. VoIP requires additional protocols to package and send this voice information through the Internet.

Andrew Prokop explained to us that, “The Internet is a way to move data back and forth, so you need other protocols on top of that. IP is the way that you address from one point to another point. But that's just the transportation protocol. Then you need some sort of session protocol or application protocol.”

“That's where something like SIP comes in,” Prokop added. “Session Initiation Protocol (SIP) rides on top of IP to set up sessions. When you make a phone call using a [VoIP] SIP network, it uses a message to invite the other party.” He continued by telling us that there was another protocol that actually moves the media, or voice data. “That's moved in a protocol called RTP, Real Time Protocol, and that's where those bits and bytes get moved across the Internet. So, you actually have multiple protocols all happening at the same time.”

• SIP - SIP stands for Session Initiation Protocol and is widely considered the industry standard for VoIP protocols today. This is due to a combination of its flexibility—it was designed to be a general-purpose way to set up and terminate multimedia sessions—and because it was modeled based on the Hypertext Transfer Protocol (HTTP). By incorporating many elements of HTTP, SIP is uniquely positioned to work with the Internet protocol. This protocol was developed and standardized by the Internet Engineering Task Force (IETF). 

• H.323 - The first widely used VoIP control and signaling protocol, H.323 has fallen out of favor for some time now. H.323 call information is written in binary instead of coded in text, which makes it more complex to transfer and, thus, slower. However, H.323 does have a few advantages, namely interoperability and better network management. H.323 is recommended by ITU Telecommunication Standardization Sector (ITU-T).

• RTP and RTCP - RTP, which stands for Real-time Transport Protocol, is used for delivering audio and video over an IP network. It works hand-in-hand with RTCP, or RTC Control Protocol, which handles transmission statistics and aids in synchronizing multiple streams of information. RTP and RTCP are often used along with signaling protocols like SIP to establish connections across networks. This makes it part of the bedrock of VoIP technology.

• Proprietary protocols - A few companies, such as Skype and Venturi Wireless, use or patent their own protocols instead of using freely distributed ones. These types of protocol give the owner the ability to place restrictions on its use and to change it unilaterally.

Why Get VoIP?

For its costs and functionality, VoIP represents a significant upgrade from traditional landline phone systems—especially for businesses of all sizes. According to Rich Tehrani, “VoIP saves money, allows for greater flexibility, assists in digital transformation, the move to the cloud, and best of all, is a newer technology, meaning you aren’t investing in something obsolete.”

VoIP phone service can save businesses money in both direct and indirect ways. For starters, VoIP can result in a 60% savings on your phone bill. When placing calls over traditional phone lines, a line is taken up by the two callers that are using it to communicate. Calls placed over landlines—particularly long-distance calls—are expensive because only so many lines can be installed. By using the Internet to relay call data, the problem is bypassed, making domestic and long-distance calls cheaper overall.

VoIP also directly saves businesses money by reducing infrastructure costs and recurring expenses. There is no copper or fiber optic wire involved in VoIP phone service, which means businesses don’t need to spend anything on private branch exchanges (PBX) and wire installation. This also means no extra costs for regular service maintenance or repairs. VoIP providers usually roll these into their subscription plans along with any taxes.

Indirectly, VoIP also saves businesses money in a number of ways. First, it encourages remote work, which saves money on utilities and office space. Second, VoIP plans typically include features such as call queueing and group ringing that cost additional fees for those with PBX. Lastly, VoIP services with an auto-attendant makes it easy for businesses with a smaller budget to handle calls and messages, something that would otherwise require the work of an in-house secretary.

Why Get VoIP?

AFFORDABILITY

VoIP is more cost-effective than traditional telephony. Because there’s more competition, prices tend to go down over time. Users save in call expenses and taxes, and it requires less infrastructure. Additionally, it encourages money-saving strategies (like working from home) for businesses.

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PRACTICALITY / FLEXIBILITY

VoIP is typically cloud-based and doesn’t require any local network topology. VoIP numbers (aka virtual numbers) don’t require a physical location. Softphone software can be used to call on your computer or smartphone, but you can also program desktop VoIP phones and then move them at will without reprogramming them.

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ENHANCED FUNCTIONALITY

Auto attendant, call transferring, multitasking (send documents, images, and video all while simultaneously engaging in a conversation), conference bridges, multimedia conversations, etc.

Individuals reap many of the same benefits of VoIP that businesses do, albeit at a smaller scale.

Like with businesses, residential VoIP customers do not have to invest in laying phone lines into their homes. Because of the way the Internet works, international calls are noticeably less expensive than what they would be on traditional landlines. And since VoIP phones are not associated with a physical location, moving does not represent an issue for your phone number, either.

An important thing to mention is that VoIP providers sometimes do not offer 911 service, phone directory listings, 411 service, or other common phone services. Because of this, some people use VOIP in addition to their traditional phone service.