Webex Bandwidth Requirements

Students, faculty, and staff can review this guide to see the typical bandwidth requirements of Cisco Webex. These tests were conducted by members of the Classroom Technology Support department and do not constitute the exact requirements of the Webex application, but rather repeated results obtained on Windows computers running the Webex Desktop App in September of 2020.

To provide reference to the following numbers, you should run an internet speed test on the device you use to conduct Webex MeetingsSpeedtest by Ookla is one of the more popular speed test websites, but many others are available. 

You can think of bandwidth as a single water-pipe that connects your house to the Internet. All the internet traffic (water) that goes to and from your house must run through that same pipe simultaneously, and you are limited by the diameter of that pipe. Even if you use a VPN to connect to UCONN-SECURE, you are still using your pipe to connect to that VPN.

The result from your speed test that you should focus on is your upload speed. Home (in contrast to a workplace) upload speed is often dwarfed by download speed. Therefore, it is more common to have a sub-optimal upload speed. In the case of Webex, your “upload” is the act of sending your voice and camera feed, along with your option of sharing your screen, into the Webex call. Your “download” is the receiving of everyone else’s voice and video, along with any shared content.

You may find that your internet speed test is reporting >100 Mbps. Please note that many results in the table below are <1 Mbps.

Bandwidth Requirements, shown as ranges in Mbps (September 2020).

Scenario

Bandwidth Used in a One-on-One Meeting in Mbps

(upload and download)

Download Bandwidth Used in a 4 participant Meeting in Mbps

(upload is the same as One-on-One)

Download Bandwidth Used in a large Meeting in Mbps

150 Participants, 25 video streams (max per screen)

(upload is the same as One-on-One)

Scenario

Bandwidth Used in a One-on-One Meeting in Mbps

(upload and download)

Download Bandwidth Used in a 4 participant Meeting in Mbps

(upload is the same as One-on-One)

Download Bandwidth Used in a large Meeting in Mbps

150 Participants, 25 video streams (max per screen)

(upload is the same as One-on-One)

voice only

0.016 - 0.150

0.030 - 0.150



Maximum bandwidth consumption achieved: 4.5 - 6 with peaks of 8

voice and video

0.600 - 0.900

1.500 - 2.000

voice, video and sharing content

0.050 - 1.300

2.500 - 3.000

voice, video and sharing video content

0.800 - 1.300

3.200 - 4.000

The usage shown above is consumed by Webex alone. If you have other devices in your house also using an internet connection, the available bandwidth to your computer will be decreased. Every device in your house must share the bandwidth available to your house.

The use of Breakout Sessions will not increase the bandwidth requirement for the Host, Cohosts, or Participants. Breakout Sessions are handled on the Webex server (call manager) side; the Host/Cohosts' computers simply tell that server how to manage/sort the Breakout Sessions. However, joining a breakout sessions will temporarily lower your bandwidth requirement since you are now connected to less users (a portion of the total participants are in your breakout session). See the above table to estimate how the bandwidth usage will change.

Officially Stated Requirements from Cisco

Webex was developed by and is maintained by Cisco. The following bandwidth requirements were transcribed from the Cisco Webex Help Center.

Maximum Bandwidth Consumption of Sending and Receiving Video:

  • High Definition Video: 2.5 Mbps (Receive) and 3.0 Mbps (Send)

  • High Quality Video: 1.0 Mbps (Receive) and 1.5 Mbps (Send)

  • Standard Quality Video: 0.5 Mbps (Receive) and 0.5 Mbps (Send)

The actual bandwidth requirements and utilization will vary based on multiple factors, including:

  • The make and model of the web camera used.

  • The resolution setting of the camera.

  • The frames per second (FPS) setting.

  • How many cameras are activated in the meeting.

  • How many active cameras are on the same network.

  • How many users are actively utilizing the network.

  • The bandwidth utilization of other meeting activities, such as screen or desktop sharing, Voice over IP (VOIP), etc.

  • Whether or not the PC in question is transmitting video or only receiving.

For the latest information regarding bandwidth requirements, and information on system requirements and supported cameras, see Cisco Webex Network Bandwidth White Paper.