What Is Bandwidth and How Does VoIP Use It?

Bandwidth refers to the amount of data your internet connection can transmit. While it’s commonly measured in bits per second (bps), you may also see it measured in kilobits (Kbps), megabits (Mbps), or gigabits (Gpbs).

Your bandwidth dictates how much information you can receive every second — this gives you an idea of how fast (or slow) you can download data, depending on available bandwidth.

Imagine you have a water hose. If the hose is very wide, a lot of water can go through it at once. If the hose is very narrow, only a little bit of water can go through at a time.

Now imagine that water as data or information. The wider the hose (or the more bandwidth you have), the more information can flow through it quickly. If you have a narrow hose (or less bandwidth), only a small amount of information can flow through, and it will take longer.

Voice over Internet Protocol (VoIP) uses the internet to transmit voice and multimedia data. Using cloud-based telephony allows you to benefit from the many advantages of VoIP, including:

• Reduced operational costs

• Improved call quality

• Remote working

However, having the right bandwidth for VoIP is crucial. As each call involves sending and receiving packets of voice data in real-time, VoIP requires a certain amount of bandwidth to transmit voice data efficiently. Inadequate VoIP bandwidth can lead to issues such as dropped calls, poor call quality, unstable performance, and more.

VoIP Bandwidth Requirements: Calculating How Much You Need

How much bandwidth is required for VoIP? Your VoIP bandwidth needs may differ depending on the size and scale of your business, so let’s find out how you can calculate your VoIP recommended bandwidth.

How Much Bandwidth Does VoIP Use?

To determine the bandwidth needed for VoIP, businesses need to consider several factors, including the number of concurrent calls, the type of codec used (codecs compress and decompress data), and any overhead (or additional bandwidth) needed for network protocols. Here's a step-by-step guide on how to calculate VoIP bandwidth requirements:

1.  Identify the Codec Used

Different codecs compress voice data differently, resulting in different bandwidth requirements. Common codecs include G.711, G.729, and Opus.

2. Determine the Bandwidth Per Call

Calculate the bandwidth needed for each call, including overhead. This includes IP, UDP, and RTP headers. Here are the typical bandwidth requirements per call, including overhead:

• G.711: ~ 80 Kbps (64 Kbps voice + 16 Kbps overhead)

• G.729: ~ 24 Kbps (8 Kbps voice + 16 Kbps overhead)

• Opus: ~ 40 Kbps (varies with compression, but assuming moderate compression)

3. Estimate the Number of Concurrent Calls

Determine how many simultaneous VoIP calls your business will need to support. The higher the number of concurrent calls, the greater your VoIP bandwidth usage. Our VoIP pricing guide will help you better understand the costs of your calls and the number of lines you might need.

4. Calculate Total Bandwidth

Multiply the bandwidth per call by the number of concurrent calls. Check out the table below to get a better idea of the bandwidth required for different numbers of concurrent calls:

To work out your VoIP bandwidth requirement, follow this general formula:

Total Bandwidth = (Bandwidth Per Call + Overhead) x Number of Concurrent Calls

For example, let's assume a business uses the G.711 codec and needs to support 20 concurrent calls.

Total Bandwidth = 80 Kbps×20 = 1600 Kbps

This means the business would need 1.6 Mbps of bandwidth for 20 concurrent VoIP calls using the G.711 codec.

How Much Bandwidth Does VoIP Require?

There is no one-size-fits-all recommended bandwidth for VoIP. The recommended VoIP bandwidth per call depends on a number of factors outlined earlier, including the codec type, number of concurrent calls, and so on.

You’ll also need to consider your network overhead (e.g., IP, UDP, RTP headers will add to your call center VoIP bandwidth requirement), as well as what additional tasks your team performs over your internet connection. You can prioritize VoIP traffic in order to improve call quality, but this may impact these other tasks.

Although there is no straight answer to the question “how much bandwidth is needed for VoIP?,” understanding these factors and calculating requirements based on your needs will ensure you have the adequate bandwidth to support high-quality VoIP communications.

How Internet Speed Can Affect Call Quality

A slow internet connection is never fun, especially when it comes to voice calls. If your internet speed is insufficient, it can lead to a range of issues that may impact the quality of your calls, resulting in misunderstandings and frustrated callers.

Latency (Delay)

Latency, or delay, is the time it takes for voice data to travel from one point to another in a network. High latency can cause noticeable gaps between when a person speaks and when the other party hears it, making conversations feel out of sync and causing interruptions.

Jitter

Jitter refers to the variability in packet arrival times. When internet speed is inconsistent, voice data packets can arrive out of order or at irregular intervals, causing choppy or distorted audio. This can make it difficult to understand the conversation and lead to a poor user experience.

Packet Loss

Packet loss occurs when some data packets fail to reach their destination, resulting in missing parts of the conversation. This can cause sentences to be incomplete or sound garbled, significantly impacting call quality.

How To Test Your Internet Speed

Conducting a VoIP test allows you to check your network quality, reliability, and speed. The results will reveal whether your network is able to handle VoIP calls and can help you avoid technical difficulties like connection drops, unsettling echoes, and background interference.

The easiest way to test your VoIP connection is through a network quality tool — if you follow the link through to ours, you’ll find comprehensive instructions on how to get started. Some top tips to follow include:

1. Prepare the Network Environment

To get an accurate baseline of your internet speed, consider testing after hours or during a period of low activity. Make sure you close all unnecessary applications and pause any active downloads or uploads which may adversely affect your speed.

2. Choose the Right Device

Use a computer or device that is directly connected to the network via an Ethernet cable for the most accurate results. Testing over Wi-Fi can be affected by signal strength and interference.

3. Test Multiple Locations

If your business operates in a large facility or multiple locations, conduct speed tests at various points to identify any areas with weak connectivity.

How Low Bandwidth and Poor Internet Speed Can Negatively Affect Your Business

There’s no doubt about it — inadequate bandwidth and slow internet speeds are detrimental to your business, and here’s why.

1. Decreased Productivity

It’s simple — your staff can’t perform their jobs well if their equipment doesn’t work properly. Slow internet speeds can significantly hinder day-to-day operations, causing delays in downloading files, accessing cloud-based applications, and loading web pages. And when it comes specifically to VoIP calls, it can be a real challenge to perform when you’re constantly dealing with dropped calls or unclear instructions. This leads to wasted time and decreased productivity, not to mention the frustration and low-morale your team will experience facing these problems every day.

2. Customer Dissatisfaction

Delays and poor responsiveness can frustrate customers, leading to dissatisfaction and potential loss of business. Providing prompt and efficient service is crucial for maintaining customer satisfaction and loyalty.

3. Security Risks

Poor internet speed can compromise your ability to perform timely software updates and backups, leaving your business vulnerable to security threats. Slow speeds can also affect real-time monitoring and encrypted communications, increasing the risk of data breaches and cyber-attacks.

Optimize Your VoIP Call Bandwidth Requirements

Understanding bandwidth is crucial for businesses leveraging VoIP for communication needs. As it relies on real-time voice data transmission, having enough bandwidth available is crucial for avoiding dropped calls, poor call quality, and overall unreliable performance.

By accurately calculating, testing, and ensuring adequate bandwidth based on factors like codec type and number of concurrent calls, businesses can optimize their VoIP infrastructure to support seamless communication, maintain productivity, and keep customers satisfied.

Get in touch with Vonage today to see our VoIP solutions in action and get support with testing your network.