Using DSCP Marking with Zoom

Differentiated services code point (DSCP) marking tags and classifies data packets so that network components can then determine which types of data traffic will have a higher priority during periods of congestion and when traversing complex network environments.

The following sections describe the available options and recommendations for tagging Zoom audio and video data.

DSCP Overview

If your organization uses DSCP marking, it is recommended that Zoom data is tagged to receive the best user experience possible

Zoom applications are designed with proprietary, adaptive features that optimize audio and video data in real-time allowing for a high-quality, consistent experience on networks with or without a QoS strategy or DSCP marking strategy.

For organizations that do utilize DSCP marking, Zoom data packets should be tagged so that Zoom’s real-time audio and video data is prioritized during times of network congestion, maintaining the best available audio and video collaboration experience.

Your QoS strategy for Zoom products may involve enabling DSCP marking in multiple locations

The following DSCP marking enablement options are provided by Zoom or are native to your legacy video conferencing appliances or network devices. Consider which options best suit your organization’s QoS strategy.

Note

To use Zoom-hosted DSCP marking or GPO-deployed DSCP marking, all Zoom desktop and Zoom Rooms apps must be deployed using an MSI file (for Windows) or IT administrator property list files (for macOS) via an MDM or Apple Configurator.

Enabling DSCP marking through the web portal or Group Policy only marks data packets outbound from Zoom apps. You may need to tag Zoom data on other devices in your network.

The DSCP marking settings in the Zoom web portal activate the tagging and classification of audio and video data heading outbound from Zoom applications in your account

Zoom account owners and administrators can enable DSCP marking for several Zoom products via settings available in the web portal. See the How to enable DSCP section of our Using QoS DSCP Marking support article for prerequisites and instructions for enabling DSCP and setting specific audio and video values.

The DSCP marking setting in the web portal enables the tagging of outbound audio and video data packets for the following Zoom applications and Zoom-enabled devices.

• Zoom Workplace desktop apps for Windows and macOS

• Zoom Workplace mobile apps for Android and iOS

• Zoom Rooms apps on Windows and macOS computers

• Zoom Phone operating on Zoom Workplace desktop and mobile apps

• Zoom Phone certified Cisco/Poly/Yealink IP phones

• Zoom VDI Plug-ins

Note

The outbound DSCP tags from Zoom products must be trusted by the computers and network components in which Zoom data traverses to keep DSCP tags intact and the audio and video DSCP classifications unaltered.

Using Group Policy to configure DSCP marking for Windows-based Zoom apps allows admins to set unique audio and video classifications required for specific users or groups

GPO facilitates the customization of Zoom audio, video, and screen sharing data classifications to accommodate higher or lower DSCP service levels for individual users or groups.

For instructions, see the How to set DSCP marking through Group Policy section of our Using QoS DSCP Marking support article.

Some Zoom applications and Zoom-enabled devices may require DSCP marking to be enabled on the device itself or through other network components

The following Zoom products do not support DSCP marking through the available Zoom web portal settings or Group Policy:

• H.323/SIP video conferencing devices using the Zoom Conference Room Connector product

• Desktop apps installed with a standard installer (macOS) or .exe installer (Windows)

• Zoom mobile applications (for iOS and Android)

• Zoom Rooms Appliances

• Zoom Phone for VDI

H.323/SIP video conferencing devices may have DSCP marking configuration options within the device settings. DSCP marking options may be available on your network components (e.g. - firewalls, routers, or switches) to tag and prioritize Zoom traffic for the above-listed Zoom Workplace apps or Zoom Rooms Certified devices that are not affected by Zoom-provided DSCP marking options.

Tagging Zoom data packets on network components allows for the proper prioritization of Zoom media and signaling throughout your network

Enabling DSCP marking in the Zoom web portal or through Group Policy only activates the tagging of Zoom data packets outbound from Zoom Workplace apps. DSCP tags may not be recognized by other internal network components, and tags can be stripped when traversing the Internet. This could potentially cause Zoom traffic to be a lower priority in your network QoS strategy, which may lead to quality issues.

Note=

Tagging Zoom data packets both inbound and outbound on network components such as firewalls and routers helps to establish equal prioritization of Zoom traffic throughout your network, producing the best available quality for Zoom Meetings, Webinars, and audio calls.

MSI switches and Plist keys are available to split Zoom audio, video, and screen sharing traffic to individual ports for network-level DSCP marking

By default, all Zoom Workplace apps and Zoom Rooms media and signaling data is combined and transmitted over UDP port 8801. Zoom Workplace desktop and Zoom Rooms apps that are deployed using MSI files or Plist can enable a switch or Plist key to break audio, video, and screen sharing data into the following data ports.

• Video: 8801

• Screen share: 8802

• Audio: 8803

With individual ports— network devices such as firewalls, routers, and other components have finer control when tagging and classifying Zoom media and signaling traffic.

When using DSCP marking, Zoom audio and video data is classified as part of an organization’s multi-class Quality of Service strategy

Many organizations utilize a 4, 8, or 12-class Quality of Service (QoS) strategy with DSCP tagging to ensure consistency in transporting real-time audio, video, data, and control signaling on their network.

The following tables demonstrate the common Zoom DSCP values and which service class they reside within for 4,8, and 12-class QoS strategy models. DSCP values for Zoom traffic can be customized to fit your organization’s prioritization of video and audio communications data.

Suggested Quality of Service Models

4-class QoS model

Service Class	DSCP Name	DSCP Value	Common Zoom data classification
Real-time	EF	46	Zoom audio, Zoom Phone, Zoom Contact Center
CS5	40	Zoom video/screen sharing
Signaling & Control	CS3	24
Transactional Data	AF31	26
Best Effort	DF	0

8-class QoS model

Service Class	DSCP Name	DSCP Value	Common Zoom Classification
Voice	EF	46	Zoom audio, Zoom Phone, Zoom Contact Center
Interactive Video	AF41	34	Zoom video/screen sharing
Streaming Video	AF31	26
Network Control	CS6	48
Signaling	CS3	24
Transactional Data	AF21	18
Best Effort	DF	0
Scavenger	CS1	8

12-class QoS model

Service Class	DSCP Name	DSCP Value	Common Zoom Classification
Voice	EF	46	Zoom audio, Zoom Phone, Zoom Contact Center
Broadcast Video	CS5	40	Zoom video/screen sharing
Real-time Interactive	CS4	32
Multimedia Conferencing	AF41	34
Multimedia Streaming	AF31	26
Network Control	CS6	48
Signaling	CS2	16
OAM	CS2	16
Transactional Data	AF21	18
Bulk Data	AF11	10
Best Effort	DF	0
Scavenger	CS1	8