5 minute read |

How VoIP Phones Work

VoIP phone service background
VoIP Services

Are you interested in how VoIP phones work and how you can make use of them? You are just in the right place.

Just as we need a phone instrument to place a call over the Public Switched Telephone Network (PSTN), VoIP calls also need certain devices in order to connect two or more people.

But that is where the similarities end. While analog phones are generally divided into wired, wireless and cell phones, there are many more options available to make and receive VoIP calls.

What Are VoIP Phones?

Essentially VoIP phones are devices that are capable of transmitting calls over the Internet – hence the name Voice over Internet Protocol – instead of through the PSTN.

One crucial difference from normal phones is that VoIP devices are digital whereas the older landline instruments were analog devices.

While it is possible to use traditional analog instruments to replace calls to the VoIP network by using VoIP adapters – also called Analog Telephone Adapters (ATA) – these are not widely used.

They may be offered by VoIP vendors to consumers who do not want to pay for a new VoIP phone. Business enterprises utilize these adapters as a transitional device until they can purchase and install IP capable phones.

The main issue with utilizing adapters is that users cannot take advantage of the latest VoIP features that are built into modern IP phones.

Types of VoIP Phones

VoIP phones are available in all shapes and sizes – from extremely basic software applications to sophisticated desk phones with built-in options for conferencing, video, shareable contact lists etc.

Since these devices run the gamut of software and hardware applications, they are commonly referred to as clients or endpoints (since the specific device can easily be swapped out for another).

Softphone – These are basically software applications that are installed on computers. They utilize the computer’s built-in speakers and microphone or a dedicated headset to make and receive VoIP calls.

Mobile VoIP app – These applications can be installed on smartphones and tablets to place VoIP calls. They are often categorized differently from other softphones as they are a relatively new phenomenon.

Mobile VoIP apps have become extremely popular among consumers and businesses often integrate these apps so that employees can use their personal phones for work.

Hardware VoIP phone – These devices look and feel the same as a traditional desk phone, except they are capable of transmitting VoIP calls over the Internet. Such devices usually have integrated mini hubs so that they do not need a separate network point.

Essentially they can share network access with the computer which can be valuable to an organization setting up hundreds of new phones.

How VoIP Phones Work

Hardware based VoIP phones are the most commonly used instruments for placing VoIP calls. They usually – but not always – have the following hardware components:

  • Speakers, microphones and/or earpieces
  • Keypads to enter phone numbers
  • Displays to show messages, voicemail, email etc.
  • Ethernet ports to share a data connection with the computer
  • A power source that may be a battery or AC adapter (some phones can be powered through the ethernet port itself via PoE)
  • AD/DA to convert voice signals to digital data and vice versa
  • Network hardware and general purpose processor

More high-end instruments may have cameras to enable videoconferencing, touchscreens, function keys etc. but the above basics are necessary for any hardware IP phone.

These phones also have to be compatible with the protocols and audio codecs supported by the VoIP service provider. SIP is the most commonly used VoIP protocol and it is supported by a wide variety of hardware.

VoIP phones convert the human voice into digital data packets that can be transmitted over the Internet. When these data packets reach the destination, they are reconverted into audio signals so that the message can be heard by the other party.

Many of these devices have automatic provisioning so that they can be authenticated on the VoIP server without manual intervention. Although the underlying technology powering these phones is fundamentally different from the PSTN lines, the end-user experience remains unchanged.

Limitations of VoIP Phones

Unlike analog instruments, these phones require a constant power supply. This makes them particularly unreliable during emergencies and disasters. Fortunately most businesses include power backup for the phone system so that employees can continue to make calls.

Although it is more a limitation of VoIP technology itself, these phones cannot be used to make 911 calls. While there have been efforts to implement a digital version called – E911 – it is not as widespread as it should be.

VoIP phones require a constant and high-speed Internet connection to make calls. Audio quality can easily be compromised by network congestion, high numbers of concurrent calls, poor QoS settings etc.

In addition, these phones can be subjected to DDoS attacks, malicious software, viruses and other issues that normally plague any network device.

In spite of the limitations – which are likely to be solved as time goes on – VoIP phones are here to stay. Any business enterprise that wants to deploy VoIP should understand how the different hardware and software works together to form a seamless phone system.

Ready to get started with VoIPstudio?

Start a free 30 day trial now, no credit card details are needed!

Thousands of businesses across the world trust VoIPstudio for all of their most vital business communications. Why not be the next?

Thousands of businesses across the world trust VoIPstudio for all of their most vital business communications. Why not be the next?

Start a free 30 day trial now, no credit card details are needed!