Zoom provides configuration options to limit the amount of bandwidth allocated for audio and video based on IP range. This feature is provided for administrators familiar with network configuration, and the policies are intended for local networks known to have limitations at specific locations.
Before using this feature, Zoom strongly recommends reaching out to your Zoom support team for advice and consultation. Limiting bandwidth should only be done in very specific circumstances. Zoom applications are designed to measure and allocate bandwidth as needed. For most deployments and situations, Zoom can adapt to changes or limitations in available bandwidth without additional policies. Zoom will always provide the best user experience when allowed to calculate what is available. If you decide to implement policies that limit bandwidth, you should be aware that reduced bandwidth will impact quality.
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Bandwidth limit policies are defined by using both required and optional information. The following is a summary of the fields for each policy.
This is a required field used to identify the limit policy being created. While there are no rules for entering a name, the recommendation is for a name that can associate the IP range you are creating a policy for with a location or network identity.
This is an optional field that can be used to provide more detailed information about the created policy. Providing a description is a recommended procedure to ensure that policy information is clear for anyone reviewing what has been configured.
If your policies increase over time, the extra thought put into adding a description will be useful when reviewing policies later and for anyone coming into an administrator role that needs to understand previous configurations.
Note: The IP ranges you create must be in IPv4 format.
This is a required field and is the primary information used to determine how bandwidth limits are to be applied. This field supports both a range or a subnet mask. It is recommended that you become fully familiar with network terminology for IPv4 range configuration before configuring policies.
This is a required field used to configure the maximum amount of bandwidth that can be allocated for sending audio and video from the Zoom application to the meeting.
Please note that this value also limits the amount of bandwidth allocated when sharing presentations, as well as audio and video from a participant. Configuring a low value will affect the quality received by other participants. Greatly reducing the available bandwidth will limit the quality of video in particular. A typical result for meeting video when bandwidth is limited is lower resolution received by other participants. At the minimum value, the reduced resolution can be particularly noticeable when the participant switches to speaker mode and fills the screen.
This is an optional field that should be configured only when network bandwidth is severely limited. Users have the ability to select different viewing options. Different layouts can require different bandwidth allocations depending on the number of participant audio/video streams being received along with any content. Restricting the bandwidth received by limiting the value through a policy can be used to address limitations for multiple users on a network where capacity is a problem.
However, while helping to address maximum capacity, the limitation will also limit quality for a single user even when bandwidth may be available. In many deployments, the software client’s ability to negotiate and adapt to changing network bandwidth conditions can respond more appropriately to those changes than completely restricting bandwidth at all times through a policy. Please consult with Zoom before using the Downstream policy to limit audio/video and content.
This is an optional field added as an enhancement to the Limit Network Bandwidth configuration options in 2022. This addition helps administrators organize bandwidth limit policies.
With a large number of policies, it can be difficult to find a specific policy or understand how a set of policies are intended to support a location. Labels provide a way for administrators to group associated policies together. With the ability to create both Labels and Sub-Labels, it is possible to take multiple policies for a single location and organize those using labels.
This is an optional field that provides administrators with the ability to limit a range of IP addresses. Using an exclusion range can be more efficient than creating two policies to accomplish the same objective.
There are two checkboxes that can be used to completely disable video from being either sent or received: Do not send video and Do not receive video. These options will significantly reduce the amount of bandwidth required for meeting participants but also severely limits the user experience. These options should only be used for networks where capacity is limited and there is no other option.
In addition to creating bandwidth limit policies individually by using the Add Limit dialog box, it is possible to use the Import button to select a file containing multiple policies for a bulk import operation. The import option requires a comma-separated value file (.csv) with values in the correct order.
More information is available about format requirements in the Import dialog box. A link to download a sample file is also provided within the Import dialog box. Another option is to create some policies using the Add dialog box and then use the Export All option to obtain a CSV file. Either approach will provide a useful reference for using a spreadsheet to define IP ranges and policies.
When importing policies using a CSV file, each row in the file will be checked to validate format and input requirements. If an error is detected, the import operation will stop. An option to download a file containing the errors will be provided to help the administrator understand which lines need to be fixed. When all error conditions are corrected, the import operation is allowed to proceed and the contents of the CSV file added to the database.
The Import option will replace existing rules when an existing rule has an IP range that matches the imported rule. Rules that define overlapping IP ranges will not be imported.
Existing policies that have been created can be exported–by using the Export All option—as a comma-separated value file (.csv) that can be imported into a spreadsheet for reference and modification.
Changes made to the spreadsheet can be imported back into the web policies using the Import option.