G.729 vs G.711 VoIP Codecs: Definitions & Which Is Best in 2022

Cody Cromwell
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G.729 vs G.711 at a Glance

G.729 is an ITU standardization recommended audio codec for use in VoIP. It originated at CCITT as recommendation G.723 based on prior CCITT standardization for G.711. G.729's development began in 1995.

G.711 is a well-known ITU standard audio codec that is currently recommended as a voice codec for use in G.729.

G.729 is newer than G.711 and it requires 64 Kbps PSAP calling capabilities, which means that in order to use G.729, trade-offs have had to be made for poorer voice quality than with G.711.

G.711 is better at speech quality than G.729 (but its abilities are limited), which makes it the standard codec of choice for quality, instead of the newer codec of choice.

G.729 provides the same voice quality as G.711 but at a lower bitrate – therefore providing better quality in a tighter bandwidth.

G.729 has a bitrate configuration capability that gives high-end audio quality, but gives the opportunity for high-end signaling bandwidth capability. This allows G.729 to support 3 or more voice call channels on a single circuit.

G.729 provides packet loss concealment capability.

What’s the Difference Between G.729 vs G.711?

G.729 and G.711 are two very similar video compression codecs that are used to transmit video signals over voice-grade networks. They are referenced by ITU-T recommendation G.729 Annex A and G.711 Annex A, respectively.

Just like JPEG and MP3 are used to digitally compress images and audio, the video codecs allow for efficient data storage while also allowing for the transmission of high-quality video signals over low-speed networks. The G.729 and G.711 codecs are used mainly for the two multimedia communication types as defined by ITU-T, that are most used in voice over IP (VoIP) applications.

As video compression standards, G.729 and G.711 are both used on VoIP deskphones as well as end-user devices ranging from laptop computers to tablet computers, when the device’s operating system supports it.

Below are some of the differences between G.729 and G.711 codecs:

G.729 can efficiently transmit video signals from 352 Kbps up to 1.536 Mbps, while G.711 can accomplish the same task at rates from 32 Kbps up to 133 Kbps.

How Much Bandwidth Do I Need for G.729 vs G.711?

G.729 is typically used for low delay, less bandwidth being utilized applications and is typically used on a regular telephone line. G.711 with better delay performance is typically used for bandwidth intensive, high bandwidth applications like VoIP or IP based video services.

In comparison to other commonly used codecs like GSM/EDGE or GSM/CDMA, G.729 does not need a very broad range of transmission frequencies to perform while G.711 does. So bandwidth on these lower frequencies is significantly lower. And with less bandwidth consumed, G.729 proves to be better than G.711 in terms of bandwidth efficiency.

In the higher frequency band, though, G.711 is said to be superior due to its better delay performance and overall higher quality of service.

Bandwidth Limitations for VoIP

A bandwith limitation exists on every Internet connection. Bandwith in the field of telecommunications refers to the total amount of data that may be transmitted over the network per unit of time, which is measured in kilobits or megabits per second (Kbps or Mbps).

Bandwidth limitations have traditionally been a problem when it comes to IT networks. But today, with the growth of IP telephony and VoIP, they also become a factor for the phone lines.

Bandwidth limitations exist because each data transfer, or call, on a regular phone line represents an actual physical connection between your phone, the customer access switch, and the PSTN (Public Switched Telephone Network). When you are using a VoIP codec, the physical connection is established between your phone and the internet by way of the servers that house the voice data you wish to download through the use of an IP network protocol. So the bandwidth limitations on your VoIP connection are determined by the type of codec and capacity of the internet connection. If you use a G.729, you may have a maximum bandwidth that is less than that of a G.711 codec. Similarly, with the WAV or GSM codecs, depending on the quality of line you have, you may have limitations on your bandwidth.

G.729 vs G.711 VoIP Codecs: Pricing

Regarding Voice Quality and Which Is Right for You.

G.711 is most popular and widely deployed codec in the world. This is what we call narrowband codec or ”bandwidth efficient” ITU G.711 codec. To understand the difference between G.729 and G.711, we must first understand about ITU G.729.

ITU G.729 is a component of the ITU-T Recommendation G.711 that specifies the profiles of a low bitrate, narrowband, companded-speech audio codec and defines the parameters of the coding algorithm. The ITU-T recommendation was approved on the 1st of August, 1996.

This codec is used in VoIP land over 3G mobile networks as the standard voice compression method and also in GSM networks to compress and modulate the voice signals in GSM.

The ITU G.729 Standard provides for bitrates ranging from 64 kbps to 131 kbps. It is also referred to as narrowband (or bandwidth efficient) G.711 because it can achieve bandwidth efficiencies near 50%, compared to wideband (or bandwidth constrained) G.711.

G.729 is ITU recommendation, which means it is a standard for telecommunications. It is considered a standard because it is standardized within the ITU with very high standards.

As an ITU standard, G.

Pros & Cons of G.729 vs G.711 VoIP Codecs

G.729 and G.711 are currently the most popular codecs in the world. They’re used in the most basic voice communications applications in enterprises and most of the time in public switched telephone networks (PSTNs).

So What’s the Difference Between G.729 and G.711?

Both codecs are capable of encoding voice and carrying it through a wide range of transmission bandwidths. Through its abilities, G.729 is able to more accurately preserve audio characteristics of human speech compared to other codecs.

However, G.711 is only capable of handling half bit-rates compared to G.729. This means that G.711 would lag behind in terms of quality if it is used on a channel that’s transmitting voice with higher bitrate than double the original. On the other hand, G.729 would be relatively less sensitive to such bandwidth variations, keeping the audio quality relatively the same.

Using a channel with higher bandwidth also means that the network’s packet loss will be higher than on a channel with lower bandwidth. This is something that will impact the quality of the sound even further and is something that G.729 would be less likely to experience.

Pros & Cons of G.729

Vs G.711

Historically, G.711 has been the primary codec most used for VoIP networks and video conferencing. However, in recent years more widespread adoption of G.729 has been seen.

G.711 is relatively simple codec, and in general it has higher bandwidth (bitrate and sample rate) with lower frame size. The decision to choose G.711 or G.729 can sometimes been a tough one — though it depends on who you ask.

The main advantage to using G.711 is that it’s generally a bit easier to implement in new VoIP networks and it can run on older systems. It also has a higher likelyhood of compatibility with systems & networks.

It’s important to note that G.729 is newer than G.711, and so it’s advisable to use the newer codec whenever possible. This can be a difficult task, and every VoIP system may not support both codecs. If you do need to implement G.711, make sure to also implement HD Voice.

G.729 Versus G.711

Pros & Cons of G.711

Vs G.729

In this post we discuss whether G.729 or G.711 is better for VoIP and Skype-over-IP. We will also provide specs, vocal pitches, audio bit rate, and audio codecs comparisons, along with example call recordings.

Background

The most widely adopted codec for telephony, G.711 is a 64 kbps adaptive bit rate codec (ABR), which means it adjusts bit rate according to the average bit rate of the speech samples. Just like G.722, G.711 supports up to 8 kHz sampling rate.

AVG1 (G.703)

G.711 codec with a bit rate of 64 kbps was the best audio codec of the 21st century. AVG1 or G.703 is pretty much the same as G.711, but it is used mostly in North America for legacy TDM circuit-switched TDM telephone systems, and when G.711 is not possible.

The basic difference between G.711 and G.729 is in the audio codec.

G.729, also known as Polycom codec, is more preferred over G.711 because G.729 supports higher quality and more control than G.711. Originally, G.711 was adopted for voice transmission only. Still, generally G.711 is referred as 64 kbps audio codec for telephony.

Who the G.729 Codec Is Best For

Who is G.729 best for?

Tech insiders (and literally anyone involved in telecom or VoIP) will tell you that G.729 (the codec we’re going to talk about today) is best for the enterprise (specifically for business-to-business). However, it’s also going to be used for residential applications.

Why?

Because G.729 is considered the future of voice compression. It’s the de facto voice codec in a suite of standards called (surprise) G.729. There’s not just the one codec with a G.729, though. G.729’s flexible that way. It’s designed to be used with various other voice codec standards like G.711.

In the meantime, since the infant days of voice compression, many attempts have been made to create a voice codec that combines good voice quality at low bitrates. However, the industry consensus has been that the trade-off is generally a lower quality of conversation and is a mediocre solution.

In G.729, the compromise between quality and bitrate is less. And it’s pretty much been proven in experiments that G.729 delivers the best quality of conversation for a given bitrate.

Who the G.711 Codec Is Best For

As you may know, G.711 is the typical codec used for voice communications in virtually all VoIP systems today. This includes Voice over Wi-Fi (VoWi-Fi), Voice over LTE (VoLTE), and Voice over the Internet Protocol (VoIP). G.711 is a 10-bit audio codec and can represent a wide dynamic range that can be adjusted to the customers needs.

Compared to the G.722 and G.722.1 codecs, G.711 offers the least amount of transcoding opportunities and is the most limited by bandwidth and raw bitrate demands. This becomes especially evident in mobile applications when compared to G.722.1.

G.711 is also the most efficient of the three codecs, while still offering adequate quality. G.722 is the only codec that is coded in 16-bit and can benefit from improved conversion layers. This can improve voice quality, especially with the addition of the G.722.1 enhancements.

G.711 is typically the default or preferred compression codec for enterprise VoIP because of the high level of performance and its support for wide ranges of dynamic range, allowing the codec to be fine-tuned for the client’s specific needs.

Frequently Asked Questions (FAQs)

What is G.729?

G.729 is a voice compression standard that compresses voice signals at 8-kbps using a 64-kbps sampling rate. A 64-kbps sampling rate means that the quality of a voice signal is reduced by a factor of three compared to a standard 32-kbps sampling rate. G.729 performs better than G.711 at 8-kbps but costs more since it requires an additional 64 kbps of bandwidth for each voice call.

What is G.711?

G.711 is a voice compression standard that compresses voice signals at 8-kbps using a 32-kbps sampling rate. A 32-kbps sampling rate means that the quality of a voice signal is reduced by a factor of two compared to a standard 64-kbps sampling rate. G.711 performs better than G.729 at 8-kbps but costs less since it requires an additional 32 kbps of bandwidth for each voice call.

Is G.729 the Best Codec?

What is a codec?

A codec is a computer program that encodes and decodes data. Similar to how a word processor prepares a text and how a graphics program translates a file to a graphic image, a codec translates data from one format to another. For example, a G.729 codec converts an audio file into a G.711 codec.

A codec is defined by its associated algorithm; it is not a specific tool as much as it is a method of encoding and decoding data. This introduces a problem for companies which want to standardize the codecs that their software uses; different codecs may offer similar compression of same audio file, but they may have different compression algorithms, which may cause incompatibility.

A codec is generally divided into two parts: the encoder and decoder. The encoder uses a combination of mathematics (or hard-coded rules) to compress audio data. For example, G.729 decoder uses a set of hard-coded rules to carve out an efficient encoding for compressing a file. In contrast, G.711 decoder uses a set of hard-coded rules to decode a file into an efficient audio format for playback. A codec is not as efficient as its counterpart, the decoder. That is where codec choice and the corresponding codec file come in.

What is data transmission?

Data transmission is the process of sending data from one independent computer to another over a communications standard.

Data transmission standards, also called protocols, are nothing more than the format, rules, and limitations of how and when data moves through a communications network/medium such as phone line, cellular, wifi, internet, or any other wired or wireless medium.

So when we talk about a codec it means that every data transmission is encoded, by converting the data into a signal, before the actual transmission.

Similarly, decoding is the process of transforming digits into a signal like the original data/cipher for correct decryption.

The quality and speed of a codec is determined by many factors:

  • The data rate
  • Battery life
  • Bandwidth/cabling speed
  • Codec quality
  • Quality of the receiver (phone)

So bench marking the data rates and parameters of a codec is complicated and the most efficient and meaningful results can only be obtained through field tests.

Codecs are capable of encoding and decoding digital data. There are various codecs available and are often confused with codecs. So what is the difference between the two?

Codecs are exclusively used for sending digital data (i.e. audio, video, and web page) while codecs are used when sending both digital data and voice.

Codecs or codecs include:

Are there other VoIP audio codecs besides G.729 & G.711?

G.729 and G.711 are the two most used codecs today but Microsoft has partially upgraded to G.722 in its Windows 10 operating system. This is the most recent codec that is produced by Skype. These are different from CAS (Codec-Annex A), 3GPP, or VoIP protocols. G.729 and G.711 have been studied extensively for a couple of decades (even before the Internet) but had their flaws compared to what you may want in a good codec. Currently, G.729 and G.711 are used for voice calls but are perfect for voice over IP (VoIP) providers but tend to use a wider bit-rate for narrow band/voice over IP (VoIP) that is not perfect for voice over IP (VoIP) calls. G.729 and G.711 use 16 kHz sample rate, 200 µs frame size, and are constant-quality modes.

What is G.729?

G.729 is a voice codec developed by AT&T in 1996. Most commonly used for regular VoIP calls and voice over IP (VoIP) Internet Protocol calls. G.729 is specially designed for GSM networks and is guaranteed to work over GSM/GPRS/EDGE and UMTS/HSPA+ networks for standard bearer services. It is usually used in regular phone calls but some countries are using it for picking up calls through PSTN.

Bottom Line

G.729 is Still the Better Codec for VoIP

Here's an updated analysis of audio compression tools involved in VoIP : G.729, G.711, G.722, and G.726 vs G.711. The last two are the new coders that are designed for high bit rate audio and that will be used in 2022 and beyond. They will almost assuredly enable betterquality, less-affected sound than G.711, and G.711 will keep advancing as well.

So what's the bottom line? G.729 codec is still the preferred choice when it comes to audio compression in VoIP networks. G.711 is a contender — it is the codec of choice for most operators these days, but is arguably a less quality option than G.729 if using the recommendations that have been announced. G.711 will almost certainly continue to advance its sound quality for better quality and less-affected sound, but it is unclear how much will they be able to improve.

The top VoIP providers and equipment vendors like Cisco, Polycom, Viptela, and Nortel have all announced that G.711 will be the ubiquitous standard for voice quality in voice over IP ( VoIP ) networks in the near future. And as the need for high quality and less-affected sounds increase, as they are now, these vendors are certainly right.