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How to calculate video conferencing bandwidth requirements

Image motion, frame rates and screen resolution often dictate video conferencing bandwidth requirements. Learn four steps to address remote and office video call bandwidth needs.

The rapid shift to remote work has led to rapid adoption of video conferencing. About 82% of companies are now...

using it for all or most meetings, and nearly 87% say that video conferencing is a critical or important technology for business operations, according to Metrigy's "Workplace Collaboration: 2021-22" study. Video conferencing provides a richer experience for distributed workers, enabling the sharing of nonverbal communications and a higher level of engagement.

Today, most companies meet their video conferencing needs through cloud-based services, either public or custom-hosted. But the shift to cloud doesn't absolve IT leaders of responsibility for ensuring high-quality end-user experiences. Rather, the increased usage of video for both in-office and remote workers dramatically increases the need to ensure a high level of video performance.

What are the minimum video conferencing bandwidth requirements for remote work?

Thanks to adaptive codecs and AI capabilities increasingly available in video conferencing services, remote workers can achieve a respectable video experience almost regardless of available bandwidth. However, high-quality performance requires minimum available bandwidth. For example, Zoom noted the following maximum bandwidth requirements for each resolution level for one-to-one video calling:

  • High-quality video: 600 Kbps (up/down)
  • 720p HD video: 1.2 Mbps (up/down)
  • 1080p HD video: 3.8 Mbps/3.0 Mbps (up/down)

For group video calling, requirements increase to:

  • High-quality video: 1.0 Mbps/600 Kbps (up/down)
  • 720p HD video: 2.6 Mbps/1.8 Mbps (up/down)
  • 1080p HD video: 3.8 Mbps/3.0 Mbps (up/down)

Competing vendors such as Cisco Webex and Microsoft Teams require similar bandwidth for their own video conferencing services. Actual bandwidth required for a given session varies based on motion and image type.

For those with high-speed cable or fiber home services, these requirements should be easy to meet. But IT leaders should evaluate specific remote worker network performance to include not only available bandwidth, but also latency and jitter that can adversely affect voice and video performance. They should also evaluate potential of other services, such as video streaming and gaming, to compete for and interfere with available bandwidth for video conferencing.

How to calculate video conferencing bandwidth requirements in the office

A key requirement for a successful video conferencing deployment is ensuring sufficient bandwidth between endpoints to support high-definition video applications and room systems. Two parameters drive video conferencing bandwidth requirements:

  1. The bandwidth per video conference call.
  2. The number of concurrent video conference calls on each network link.

These two parameters serve as the basis for the four steps organizations must take to ensure sufficient bandwidth for video conference calls across the company.

1. Determine video conferencing bandwidth requirements

Video conferences can require anywhere from 128 Kbps for a low-quality desktop endpoint to upward of 20 Mbps for an immersive multiscreen HD system. Video conferencing bandwidth requirements are driven by the resolution and the ability of the session to handle image motion.

The table below provides typical examples of video conferencing bandwidth requirements, considering the specified resolution and frames per second (fps). Frame rate determines the ability of the video call to handle motion, while resolution determines how many pixels are on the screen image -- and, thus, how much detail users will see in that image.

These bandwidth requirements are per screen, so dual and three-screen systems may require additional bandwidth.

Video conferencing bandwidth requirements

Bandwidth Resolution Frame rate
384 Kbps Common Intermediate Format (CIF) 30 fps
512 Kbps 4CIF 15 fps+
768 Kbps 4CIF 30 fps
1 Mbps HD720 15 fps+
2 Mbps HD720 30 fps
4 Mbps HD720 60 fps
6 Mbps HD1080 30 fps
~7 Mbps HD1080 60 fps

Use these values as guidelines to assess network bandwidth. But remember to obtain specific requirements from your vendor, because bandwidth needs are typically affected by the choice of codec, compression and proprietary system capabilities.

Also, the video conferencing bandwidth requirements in this table are for the amount of traffic supported inside the Real-Time Transport Protocol (RTP) packet payload. The actual bandwidth on the IP network -- after adding RTP, User Datagram Protocol, IP and Ethernet headers -- will be about 20% higher. So, 1 Mbps video conference calls actually use about 1.2 Mbps of network bandwidth. I refer to these values as transport bandwidth (1 Mbps) and network bandwidth (1.2 Mbps) to avoid confusion.

To determine the right resolution and frame rate for your company, make sure users experience the video conference calls in the actual context where they will be used, such as the desktop, mobile device or conference room. Additionally, users should experience the video calls with the screens or projectors you plan to use, so you can determine if the quality is sufficient.

If end users are not comfortable with the quality, they will quickly resort to other methods of communication, such as a phone call or travel. Between quality and cost, there's a tradeoff. So, while users may prefer high-definition 1080p 60 fps, the cost of provisioning sufficient bandwidth to support conferences at that resolution and frame rate may be cost-prohibitive, especially in underserved parts of the world.

2. Estimate concurrent video conference calls

The next step is to determine how many concurrent calls each WAN link must support.

For small offices, with only one or two video conferencing systems, assume the two systems are running concurrently. For larger offices, estimate how many video conference calls occur concurrently based on your busiest meeting times. A helpful guide is to assume half of your video conferencing room systems are being used, then adjust bandwidth needs based on actual usage.

Once you have estimated your room system video conferencing bandwidth requirements, add in expected desktop video use by calculating the number of meetings that use video and the percentage of participants who typically have their cameras turned on. Supporting data for these estimates is often available from your video conferencing vendor's management application.

If your organization has offices across multiple time zones, factor in time shifts. Map the call patterns onto the network topology and create a spreadsheet to track concurrent call assumptions and the bandwidth per call. A spreadsheet will allow you to modify parameters to create what-if scenarios.

3. Beware of the video conferencing bridge (for on-premises systems)

If you are still using on-premises servers to support your video conferencing needs, the video conferencing bridge, or multipoint control unit, is a bandwidth hotspot. All video conferencing endpoints in concurrent multipoint video calls will connect directly to the bridge. Thus, the bridge needs to be in a location that supports a high-bandwidth connection. Consider enabling call admission control, if available, to ensure the number of concurrent video calls does not exceed available bandwidth.

4. Ensure sufficient internet bandwidth for cloud apps

Most companies have now adopted cloud-based video conferencing services, either as standalone applications or as part of a unified communications suite. Supporting the bandwidth needs of cloud video adds another wrinkle to the equation as each endpoint, whether room or desktop, will need to connect to the cloud provider.

Ensure you not only have enough bandwidth between locations to meet video conferencing needs, but also between the WAN and video conferencing provider. If internet connection is through a limited number of access points, you will need to ensure they have sufficient available bandwidth to support the quality and number of concurrent sessions you have previously estimated.

Alternative means of ensuring sufficient bandwidth are to enable remote sites to directly connect to the internet, or to use cloud federation services that allow you to directly connect your WAN to your cloud video conferencing provider.

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