How to set DSCP QoS for Wildix devices and Web Phone

This document explains how to set DSCP to ensure QoS on Wildix devices and Web Phone

Created: June 2018

Updated: January 2023

Permalink: https://wildix.atlassian.net/wiki/x/qQ7OAQ

Setting DSCP QoS for Wildix devices

To set DSCP (Differentiated Services Code Point) QoS (Quality of Service) for all the Wildix devices (WP4X0 series phones, media gateways):

  • Set DSCP value at af41 or higher in WMS Settings -> PBX -> SIP-RTP
  • Configure all the routers / firewalls to prioritize such traffic

Important: after having changed DSCP value, to apply the changes in WMS network, it is necessary to restart WMS network in WMS Settings -> PBX -> WMS Network.


It is possible to enable / disable DSCP QoS for WebRTC phone (Collaboration on Chrome) and Wizyconf conference in Collaboration Settings -> Web Phone -> DSCP QoS:

  • Default: If DSCP value is set to af41 or higher in WMS Settings -> PBX -> SIP-RTP, then DSCP is enabled by default
  • On / Off: Force DSCP on or off, independently from the settings on SIP-RTP page

For Vision/ SuperVision phones series, Collaboration on Android for WiFi and WP600AXX series phones: DSCP value set on SIP-RTP page in WMS is applied. 

Note: iOS currently does not support setting QoS via DSCP.

Note: occasionally routers / firewalls / operators can block traffic with DSCP settings different from 0 (prioritized traffic could be dropped), in such case:

  • Administrator must disable globally DSCP QoS in WMS Settings -> PBX -> SIP-RTP
  • User can disable QoS separately for WebRTC Phone (Web Phone on Chrome) in Collaboration Settings -> Web Phone
  • User can disable DSCP settings in Android app -> Advanced Settings, in Phone app on Vision/ SuperVision series phones and on WP600AXX series in Settings -> Developer

Setting QoS Policy for Windows

You can use QoS Policy as a central point of network bandwidth management across your entire Active Directory infrastructure by creating QoS profiles, whose settings are distributed with Group Policy. 

QoS policies are applied to a user login session or a computer as part of a Group Policy object (GPO) that you have linked to an Active Directory container, such as a domain, site, or organizational unit (OU).

QoS traffic management occurs below the application layer, which means that your existing applications do not need to be modified to benefit from the advantages that are provided by QoS policies.

Prerequisites for QoS Policy on Windows

It is possible to use QoS policy to manage bandwidth for computers or users with the following Microsoft OS supported by Wildix Collaboration:

  • Windows Server 2016
  • Windows 10
  • Windows Server 2012 R2
  • Windows 8.1
  • Windows Server 2012
  • Windows 8
  • Windows 7

As stated in the previous chapter, it is possible to apply QoS for WebRTC Phone only, which means you should use Chrome browser. 

Location of QoS Policy in Group Policy

In Windows Server 2016 Group Policy Management Editor, the path to QoS Policy for Computer Configuration is the following:

Default Domain Policy | Computer Configuration | Policies | Windows Settings | Policy-based QoS

This path is illustrated in the following image.

Location of QoS Policy in Group Policy

In Windows Server 2016 Group Policy Management Editor, the path to QoS Policy for User Configuration is the following:

Default Domain Policy | User Configuration | Policies | Windows Settings | Policy-based QoS

By default no QoS policies are configured. 

More information on QoS policies on Windows: https://docs.microsoft.com/en-us/windows-server/networking/technologies/qos/qos-policy-top 

Configuring QoS policies 

To create a Quality of Service audio policy, first log on to a computer where Group Policy Management has been installed. Open Group Policy Management (click Start, point to Administrative Tools, and then click Group Policy Management). Example of creating a QoS Policy for audio:

  1. In Group Policy Management, locate the container where the new policy should be created. For example, if all your client computers are located in an OU named Clients then the new policy should be created in the Client OU.

  2. Right-click the appropriate container and then click Create a GPO in this domain, and Link it here.

  3. In the New GPO dialog box, type a name for the new Group Policy object in the Name box and then click OK.

  4. Right-click the newly-created policy and then click Edit.

  5. In the Group Policy Management Editor, expand Computer Configuration, expand Policies, expand Windows Settings, right-click Policy-based QoS, and then click Create new policy.

  6. In the Policy-based QoS dialog box, on the opening page, type a name for the new policy in the Name box. Select Specify DSCP Value and set the value to 46. Leave Specify Outbound Throttle Rate unselected, and then click Next.

  7. On the next page, make sure that All applications is selected and then click Next. This setting instructs the network to look for all packets with a DSCP marking of 46, not just packets created by a specific application.

  8. On the third page, make sure that both Any source IP address and Any destination IP address are selected and then click Next. These two settings ensure that packets will be managed regardless of which computer (IP address) sent those packets and which computer (IP address) will receive those packets.

  9. On page four, select TCP and UDP from the Select the protocol this QoS policy applies to dropdown list. 

  10. Under the heading Specify the source port number, select From this source port or range. In the accompanying text box, type the port range reserved for audio transmissions depending on the PBX type:

    1. for Cloud PBX: 10000:59999

    2. for HW/ VM PBX: 10000:12000  

  11. Click Finish.

After you have created the QoS policy for audio you can then create a second policy for video. To create a policy for video, follow the same basic procedure you followed when creating the audio policy, making these substitutions:

  • Use a different (and unique) policy name

  • Set the DSCP value to 34 instead of 46 (this is just an example, you can set a different DSCP value, but it must be different than the one used for audio)

The new policies you have created will not take effect until Group Policy has been refreshed on your client computers. Although Group Policy periodically refreshes on its own, you can force an immediate refresh by running the following command on each computer where Group Policy needs to be refreshed:

Gpudate.exe /force

This command can be run from any command window that is running under administrator credentials. To run a command window under administrator credentials, click Start, right-click Command Prompt, and then click Run as administrator.

Keep in mind that these policies should be targeted towards your client computers. 

To help ensure that network packets are marked with the appropriate DSCP value, you should also create a new registry entry on each computer by completing the following procedure:

  1. Click Start and then click Run.

  2. In the Run dialog box, type regedit and then press ENTER.

  3. In the Registry Editor, expand HKEY_LOCAL_MACHINE, expand SYSTEM, expand CurrentControlSet, expand services, and then expand Tcpip.

  4. Right-click Tcpip, point to New, and then click Key. After the new registry key is created, type QoS and then press ENTER to rename the key.

  5. Right-click QoS, point to New, and then click String Value. After the new registry value is created, type Do not use NLA and then press ENTER to rename the value.

  6. Double-click Do not use NLA. In the Edit String dialog box, type 1 in the Value data box and then click OK.

  7. Close the Registry Editor and then reboot your computer.

If you have a computer that has multiple network adapters you might occasionally run into issues where DSCP values are shown as 0x00 rather than the configured value. This will typically occur on computers where one or more of the network adapters are not able to access your Active Directory domain (for example, if these adapters are used for a private network). In cases like that, DSCP values will be tagged for the adapters that can access the domain, but will not be tagged for adapters that cannot access the domain.

If you would like to tag DSCP values for all the network adapters in a computer, including adapters that do not have access to your domain, then you will need to add and configure a value to the registry. That can be done by completing the procedure described above. After creating and configuring the new registry value you will need to reboot your computer in order for the changes to take effect.