UniFi - QoS and Prioritization


Overview


UniFi supports QoS based on WMM (aka WME).


Table of Contents


  1. Introduction
  2. UniFi Access Points Mapping
  3. DSCP Values

UniFi Access Points Mapping


Back to Top

The UniFi AP maps DSCP value to WMM priorities and process these packets accordingly. UAP considers either DSCP or COS. It compares COS with DSCP (the first 3 bits) and takes whichever has higher value to map to WMM AC according to the table below:

DSCP P2 DSCP P1 DSCP P0 DSCP-- DSCP-- DSCP-- DSCP hex 802.1d WMM AC
1 1 1 0 0 0 0x38 7 AC_VO
1 1 0 0 0 0 0x30 6 AC_VO
1 0 1 0 0 0 0x28 5 AC_VI
1 0 0 0 0 0 0x20 4 AC_VI
0 1 1 0 0 0 0x18 3 AC_BE
0 1 0 0 0 0 0x10 2 AC_BK
0 0 1 0 0 0 0x08 1 AC_BK
0 0 0 0 0 0 0x00 0 AC_BE 

 DSCP to 802.1d mapping per WMM specifications, as supported by UniFi APs.


DSCP Values


Back to Top

DSCP values (Decimal): WMM AC

  • 0 to 7: Best Effort
  • 8 to 23: Background
  • 24 to 31: Background
  • 32 to 47: Video (except 46)
  • 46, 48 and above: Voice

On the AP receiving end, 802.11 is on top of ethernet frame. The Access Point thus sends packets onto the wire the way it receives over-the-air (without 802.11 header of course). For example, a VoIP phone sends VO packets in DSCP 46 and that will be the DSCP value of the ether frames that AP sends out on wire.


We're sorry to hear that!