How to configure QoS in VyOS 1.4 for Cisco WLC Fast Lane DSCP markings

[Ethernaut]

Hello,

I have a Cisco 9800 WLC running Fast Lane with Apple devices (iPhone, iPad, macOS). The WLC negotiates QoS with Apple clients and marks traffic with the correct DSCP values (e.g. EF for voice, AF41 for video, CS1 for background).

Now I’m using VyOS 1.4 as my WAN edge router/firewall. The access switch (Catalyst 2960L) just trusts and passes DSCP values, so VyOS should be the device that actually enforces QoS policies before sending traffic to the internet.

Question:

• How should I configure a traffic-policy shaper in VyOS 1.4 to prioritize traffic based on DSCP values?

• Is there a recommended mapping template for EF, AF41, CS1, etc. in VyOS?

Thanks!

[L0crian]

Here’s a simple policy to get you started. Just add your classes as needed:

set qos interface eth0 egress 'WAN_SHAPER'
set qos policy shaper WAN_SHAPER class 10 bandwidth '10kbit'
set qos policy shaper WAN_SHAPER class 10 match DSCP_EF ip dscp 'EF'
set qos policy shaper WAN_SHAPER default bandwidth '1gbit'

When you go to match dscp values, there are a bunch of presets so you don’t need to worry about mapping to decimal or TOS:

l0crian@NPB7# set qos policy shaper WAN_SHAPER class 10 match DSCP_EF ip dscp 
Possible completions:
   <0-63>               Differentiated Services Codepoint (DSCP) value
   default              match DSCP (000000)
   reliability          match DSCP (000001)
   throughput           match DSCP (000010)
   lowdelay             match DSCP (000100)
   priority             match DSCP (001000)
   immediate            match DSCP (010000)
   flash                match DSCP (011000)
   flash-override       match DSCP (100000)
   critical             match DSCP (101000)
   internet             match DSCP (110000)
   network              match DSCP (111000)
   AF11                 High-throughput data
   AF12                 High-throughput data
   AF13                 High-throughput data
   AF21                 Low-latency data
   AF22                 Low-latency data
   AF23                 Low-latency data
   AF31                 Multimedia streaming
   AF32                 Multimedia streaming
   AF33                 Multimedia streaming
   AF41                 Multimedia conferencing
   AF42                 Multimedia conferencing
   AF43                 Multimedia conferencing
   CS1                  Low-priority data
   CS2                  OAM
   CS3                  Broadcast video
   CS4                  Real-time interactive
   CS5                  Signaling
   CS6                  Network control
   CS7
   EF                   Expedited Forwarding