1. Help Center
  2. Just getting started
  3. Network Optimization Requirements

How to use local or group policy to mark voice traffic and configure QoS for the GreenLink Softphone in Windows?

Due to a Windows limitation, the GreenLink Softphone for Windows does not automatically mark traffic for voice (a requirement for QoS configuration). So softphone traffic needs to be marked for traffic either using local policy or group policy.

Marking voice traffic using local policy. 

Quality of Service (QoS) is determined by DSCP markings in layer 3 of IP packets. Properly configured routers will use those DSCP markings to give priority to those packets. That is advantageous for SIP signalling and RTP (media packets), because if media packets are not given priority, then the media quality can suffer if there is congestion at the router with other data traffic. By giving priority to VoIP packets, the packets should not suffer from excessive delay, provided the end-to-end network supports QoS.


In enterprise editions of Windows 7 & 8, the group policy editor can be used to set QoS for specific applications such as Bria 4. Please note that the Domain controller in corporate networks may override local group policies. You should consult with your IT administrator to work out the details if your computer is on a domain.

Please refer to the following screenshots.

1) Launch the local group policy editor

Start > Run > gpedit.msc (this starts the local group policy editor, the domain-level policy will override these settings)

Expand Computer Configuration > Windows Settings

Right-click on Policy Based QoS > Create new policy ...

 

2) Create the Voice policy

DSCP = 46

Application name = greenlink_softphone.exe

IP address source/destination = any

Protocol = UDP

Source/destination port = any

 

3) Set the QoS policy for greenlink_softphone.exe

 

4) Set the source and destination IP address to "Any"

 

5) Set the source and destination ports to "Any"

 

6) The GreenLink Softphone marks RTP packets with QoS tag DSCP 46 when the policy is active

 

7) Additional QoS policies can be added for video and SIP signaling control with appropriate DSCP values and port ranges

 

8) The GreenLink Softphone Account settings|Topology tab can be used to set the corresponding port ranges that the GreenLink Softphone will send the SIP (Control) and RTP (Voice and Video) packets out on.

8.png

If the same port ranges are chosen as the QoS policy, then the packets will be marked with the corresponding DSCP values defined.