How Much Data Does VoIP Use

by Jan 28, 2019VOICE OVER IP

How Much Data Does VoIP Use?

VoIP services are now more and more common on our smartphones. However, the more data-frugal among us might be concerned that they drain too much data. Indeed, most cell phone data plans don’t include VoIP use. It’s not uncommon for subscribers to make calls using VoIP in the hopes of avoiding distance fees. Many of them only to deplete their monthly data allocation unintentionally. Most users are unaware of how much data does VoIP use on their conversations consume, or the rate at which they use it.

The short answer is: “it depends”. VoIP data consumption ranges between 0.5 megabytes (MB) per minute of call (on the G.729 codec) and 1.3 MB/minute on G.711. This number fluctuates based on the technology employed by the VoIP provider as well as the caller’s use habit.

Understanding VoIP:

In general, there are two things to consider when estimating VoIP data or bandwidth use.

  • How many minutes do phone calls typically last?
  • How much data does each minute of call consume? Since VoIP calls transmit over the Internet, bandwidth use can get expensive. However, the per-minute cost of VoIP calls is less pertinent for business phone system users. After all, data use is directly dependant on the office’s already-existing broadband Internet service.

 To better estimate data drainage rates, it’s important to understand just how VoIP technology works. Voice over Internet Protocol (VoIP) makes calling possible without a traditional phone line by assembling digital files, such as voice or video data into packets. They are then transmitted over the Internet through the use of codecs. Codecs are compression engines which encode incoming voice data into digital streams and then decode them at their destination.

Understanding Codecs:

Today, most business-oriented VoIP providers rely on The G.711 codec to connect calls across the Internet. The relatively newer G.729 codec consumes 32 kilobits per second (kb/s). This new generation gained traction in the consumer market. G.729 can more effectively transmit High Definition sound and video data, making video calling possible. Since higher bandwidth usage matters to mobile data plan users, this codec uses a compression algorithm. The compression sacrifices sound or video quality for weight.

 The G.711 codec has found a niche as an office phone service because, unlike G.729, it does not compress voice data. Therefore, voice quality compares favorably with regular phones. Most offices have integrated broadband networks and pay a flat monthly Internet rate. Thus, higher call quality when speaking with clients takes precedence over bandwidth concerns.

Here is an easy chart for you to understand clearly how much data does VoIP use.

Codec BR NEB
G.711 64 Kbps 87.2 Kbps
G.729 8 Kbps 31.2 Kbps
G.723.1 6.4 Kbps 21.9 Kbps
G.723.1 5.3 Kbps 20.8 Kbps
G.726 32 Kbps 55.2 Kbps
G.726 24 Kbps 47.2 Kbps
G.728 16 Kbps 31.5 Kbps
iLBC 15 Kbps 27.7 Kbps

BR = Bit rate

NEB = Nominal Ethernet Bandwidth (one direction)

Basically, the NEB is the bandwidth consumption of one VoIP call per second, so basically, if you are on the call with your friend 10 minutes, how much data does VoIP use? If you are using G.711 codec, the consumption will be 52,320Kbps = 6,540KBps = 6MBps. You could just consider a very good quality mp3 song.

Calculating Data Consumption:

VoIP carriers built on the 64 kbps (Kilobits per second) G.711 codec consume bandwidth at 87 Kbps. By multiplying the number of Kilobits per second by 60, we get the KB per minute rate: 5220 KBPM. However, that only includes outgoing data. Since conversations usually take two people, that number should be doubled to take into account data received from the other speaker. Therefore, one minute of call uses 652.5 kilobits all together. Since 8 bits form 1 byte, that comes down to 1305 bytes, or 1.3 Megabyte per minute. Because the G.729 codec is more efficient in transmitting heavier data, it typically consumes 32 kbps/second. This comes to approximately 0.5 MB per minute of phone time.

How Much Data Does VoIP Use In PSTN World

In the 1960s, public switched telephone networks, or PSTNs were the mainstay of analog business calling. T1 transmission systems, which encoded speech in 64 kbits streams would soon be introduced to support the digital transition. These new carrier systems supported up to 23 simultaneous phone calls on a single telephone line. A 24th line served for signaling.

 The European Conference of Postal and Telecommunications. A decade later, Administration (CEPT) would base their E carrier on the same technology. In an attempt to avoid some of the inherent limitations of the T1 systems, E1 went with 2.048 MB/s streaming. Regardless, The original analog PSTNs’ legacy lives on to this day.

How Much Data Does VoIP Use In The Internet Age

In the Internet age, VoIP pioneers took inspiration from the already-existing physical infrastructure. This made analog communication possible when setting up their own networks. The G.711 codec audio codec on which the first VoIP networks ran still used the same stream rate as the original T-carriers: 64 Kbit/s.

 The introduction of the of the G.729 codec made HD video calls easy and available. However, the heavier payloads result in higher data consumption if uncompressed. The G.729 codec supports the architecture for popular VoIP applications like Skype and PingMe as well as streaming services like YouTube.

 VoIP applications rely on audio and video codecs to send and receive data packets. That’s how two people can have a real-time conversation over the Internet. The data stored on these packets, usually called ‘a payload,’ includes network addresses, sequencing information, and error detection mechanisms. VoIP calls may consume more or less bandwidth. This depends on how much sound is being transmitted. A human voice loads more data into IP packets and therefore using more bandwidth. On the other hand, a moment of silence consumes virtually no data. For this reason, unlike traditional phone calls, there is no set data rate per minute of use.

How Much Data Does VoIP Use In Video Calling

When trying to get a sense of the amount of data used for video calling, additional factors come into consideration.  Screen size can play a significant role in data use. Video conversations between two small devices, like mobile phones, typically consumes 3.75 MB of data per minute. On the other hand, calling a tablet from a phone might use up 4.5 MB of data for the same length. The quality of the data stream also directly affects bandwidth usage, and therefore the price of a video conversation. On the other hand, a standard resolution call might drain around 3.2 MB of data per minute. High Definition calls typically use more than 20 MB per minute of phone time.

The larger the user’s screen, the more high-quality data needs to be streamed through packets. Bigger screens lead to higher per minute costs of a video call. This high data consumption rate explains why Facetime initially only worked when users were connected to a WiFi, not on mobile data.

Ideally, the most economical VoIP technology fits the right balance between data quality and data usage. Most office phone systems don’t require video data transmissions. Thus, the G.711 codec offered by GenVoice provides a high-quality voice transmission experience. At the same time,  it runs many other business features like virtual call centers, automatic operators and so on.

Related Questions:

Is VoIP always cheaper than the alternatives?

For the most part, it is. As a rule, VoIP is indispensable for offices that make many calls per month. VoIP billings come as a flat monthly fee. For this reason, it makes sense if you’re always on the phone. This is even more relevant if long distance or overseas calls are routine. On the other hand, companies which rarely use the phone might not be able to justify the added monthly fees. The fee for a VoIP service adds to the higher bandwidth Internet and the cost of replacing all the phone terminals.

 VoIP plans are adaptable to a company’s size, expected amount of data use, number of features and so on. It’s possible for a company to be signed up to the wrong plan. This situation can lead to the needless waste of money. For instance, a small business might be on a plan costing $25 per month while only making a fraction of the expected phone calls available. For this reason, it’s always important to carefully review plans before choosing one that fits.

Why do offices switch the VoIP services?

Mostly because they save much money, and gain many perks that traditional PSTNs can’t offer. While VoIP calls cost based on the transmission of data, PSTN phone conversations always cost a lot per minute regardless of whether you’re talking or not. Offices which have VoIP-based communication systems pay only the regular price of their broadband Internet service. As mentioned above, Internet-based conversations do not use bandwidth during silent pauses. Since approximately 50% of an average conversation length contains silence, VoIP calls use bandwidth pretty efficiently. VoIP compression also supports an almost infinite number of simultaneous phone calls on the same network. This advancement comes a long way since the original T1 infrastructure. As a reminder, T1 only supported 23 conversations.

 Aside from the efficient data use during voice conversations, VoIP also comes with many features with which analog systems could never compete. Business-oriented VoIP phone systems offer caller ID, call waiting, call forwarding, digital call logs and much more. The integration of APIs, virtual call centers, and real-time calling data are indispensable components of the modern office.