When researching VoIP phones, you will find that most hardware supports multiple codecs (methods of transmitting voice information between phones). Many of our customers have wanted to know the differences between G.722 vs G.711 and how they work within a business phone system.
These two codecs are a great example of how wideband and narrowband codecs function, and they demonstrate development of this technology over a period of several decades. The following sections will define those terms and give you a wider (bad pun intended) perspective on how these options could affect how your desk phones function.
Wideband and Narrowband Codecs
In order to understand the comparison of G.722 vs G.711, it’s first necessary to learn what wideband and narrowband codecs are.
All codecs, as we’ve explained thoroughly in our What is VoIP? guide, are basically computer programs that encode and decode audio. These programs work with your phone’s hardware to create computer data from sound waves, transmit that information to a second device, and then create sound waves from that data.
There’s a lot of work that takes place within that process. Just know that codecs are analogous to languages and that phones that support more than one codec can speak more than one language.
These languages can be grouped into categories. Two primary categories are wideband and narrowband and are given these names because of the range of audio signals they can process. Wideband codecs typically handle audio frequencies between 50 Hz to 7 kHz; narrowband codecs usually work between 300 Hz and 3.4 kHz.
Wideband audio may be referred to as high-definition voice because it is able to capture a greater range of human speech, which can range from 80 Hz to 14 kHz.
A common method of rating different codecs comes with the Mean Opinion Score (MOS) that’s created from an average of callers’ reviews of the clarity of a call. As you can see in this diagram, each MOS for G.722 and G.711 are similar, but as you will read about in the following sections, they reach those high ratings in different ways.
G.711
G.711 was developed in 1972 and is part of the narrowband set of codecs. When comparing this codec with G.722, the most relevant information about G.711 to note are these two points:
- It uses an 8 kHz sampling frequency, using 8 bits per sample
- It has a 64 kbit/s bitrate
The first data point above describes the second. Every time G.711 creates an audio sample, it uses 8 bits of information. At 8 kHz multiplied by 8 bits, you get a 64 kbit bitrate.
The 64 kbit bitrate is how much bandwidth, per second, you need to available in your internet connection to handle a single phone call.
G.711 data is not compressed, so the resulting 64 kbit/s bitrate is large compared to some other codecs which use compression techniques to lower their bandwidth requirements. You can see in the chart on our VoIP Speed Test page that a similar compressed codec, G.729, can fit 16 calls into the space that one G.711 call would occupy.
G.722
Audio codecs are always improving and besting their predecessors. In 1988, G.722 was released as a wideband codec. It tries to improve on G.711 by increasing its sampling rate and using compression:
- It uses a 16 kHz sampling frequency, using 14 bits per sample
- It uses compression to achieve its bitrate of 64 kbit/s
For this codec, it begins with an uncompressed bitrate of 224 kbit/s (16 kHz * 14 bits) and reduces that figure to a usable 64 kbit/s that most modern broadband connections can easily handle.
The SB-ADPCM compression used here allows the sound quality to retain its characteristics. Therefore, when comparing G.722 vs G.711 directly, the audio of G.722 is equal to or better than its uncompressed counterpart and may offer more nuance in audio that the narrowband cannot manage.
Which of G.722 vs G.711 Is Better For You?
The answer of which codec you want to use at your own business depends on your individual circ*mstances. No two businesses are exactly alike in their phone plan use and daily tasks.
A chat with our team can help you decide which codecs are best for your needs. We can speak with you to determine your network bandwidth availability and the volume of calls you handle every day. Then we can recommend which codecs will work best in your situation — whether it’s G.722 vs G.711 or one of the many other codecs available for use, like those shown in the datasheet for the popular Yealink T23G desk phone.
In general, codecs with lower bandwidth requirements work best in networks without a lot of internet speed to spare, and codecs with higher requirements may work fine if your network supports their demands.
These are the types of issues we can discuss on our call. Additionally, we may also suggest Network Services like our VPN for VoIP option that helps your network prioritize traffic to keep your phone calls clear to your employees and customers. All of this will help you find a good fit of phone configuration at your company.
