Difference between analog, digital, and IP telephony

Posted by Rick Torres on

Those small businesses and sole proprietors who are responsible for choosing their own phone systems often run into some confusion when it comes to analog, digital, and IP technologies. This article will explain the basics about each technology and allow you to choose the most appropriate phone system for your business with more confidence.

Analog telephony, or POTS

Analog telephony, also known as POTS, stands for plain old telephone service and uses the narrow RJ-11 plug to support your standard phone, fax machine and modem. Analog technology works by translating audio (your voice) into electronic pulses. Analog is most likely the type of phone you have at your house, or used to anyways. This technology has been around the longest, and as you can probably guess, is the cheapest. Being cheap doesn't mean it's bad, however, analog has limitations on how much data can be transmitted. Therefore if you run a business with many employees its likely you'll need to use a VoIP system which we'll talk about a little bit later.


Aastra 390 Analog Phone

Digital telephony, or ISDN

Digital telephony offers more for your business than analog, and as mentioned before can transmit more data. Also, analog signals drop in quality over long distances, whereas digital signals don't. This is because of the way digital technology works, converting audio into digits at one end and then decoding those numbers back into audio at the other end. The benefit of digital telephony is that the audio encoded at one end is exactly the same as what is decoded on the other end. A major requirement for digital phones is a key service unit or KSU which is needed to operate your phone.

Inter-Tel 550.8560 8560 Axxess Digital Phone

Inter-Tel 550.8560 Axxess Digital Phone

IP telephony, or VoIP

IP telephony or VoIP stands for voice over internet protocol and uses the internet rather than telephone networks to place phone calls. VoIP is in fact a type of digital telephony and the modern business standard for phone systems since it provides so much more than its predecessors. Convenience and cost are major factors in the VoIP movement since businesses can now use their computer or IP phone to place phone calls. It's important to point out that IP telephony uses the larger/wider RJ-45 Ethernet plug rather than the smaller RJ-11 plug that analog phones use.

Polycom Soundpoint IP 450 VoIP SIP Phone 2200-12450-025

Polycom Soundpoint IP 450 VoIP SIP Phone

Final Note

This article only briefly describes the types of telephony technologies and how they work. If you would like to learn more about a specific technology we encourage you to do more research or contact us regarding any questions you may have. An important note you should take away from this article is that your budget and bandwidth needs will play a major factor when choosing the right technology. 

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