1. Best Practices for Voice Deployment with Cisco WLAN Infrastructure
  2. Device Settings
  3. Device Wi-Fi Quality of Service (QoS) Tagging and Mapping
  • Best Practices for Voice Deployment with Cisco WLAN Infrastructure
Device Wi-Fi Quality of Service (QoS) Tagging and Mapping

Device Wi-Fi Quality of Service (QoS) Tagging and Mapping

This section describes device QoS tagging and mapping of packets from the device to the AP (such as outgoing packets in the uplink direction).
The tagging and mapping of traffic in the downlink direction from the AP to the device is determined by the AP or controller vendor implementation or configuration, which is not in the scope of this document.
For the uplink direction, an application on the device sets Differentiated Service Code Point (DSCP) or Type of Service (ToS) values for its sourced packets, based on the application's specifications. Prior to the transmission of each packet over Wi-Fi, the DSCP or ToS values determine the device's further 802.11 Tagging ID assigned to the packet, and the mapping of the packet to 802.11 Access Category.
The 802.11 tagging and mapping columns are provided for reference and are not configurable. The IP DSCP or ToS values may or may not be configurable, depending on the app.
Table 3 describes the tagging and mapping values for outgoing packets when no other dynamic protocols affect them by standard specifications. For example, if the WLAN infrastructure mandates the Call Admission Control (CAC) protocol for certain traffic types (such as voice and/or signaling), tagging and mapping obey the dynamic states of the CAC specifications. This means that there could be CAC configuration or sub-periods in which the tagging and mapping apply different values than mentioned in the table, even though the DSCP value is the same.
Device Wi-Fi QoS Tagging and Mapping for Outgoing Traffic
IP DSCP Class Name
IP DSCP Value
ToS Hexa
Tagging of 802.11 TID (Traffic ID) and UP (802.1d UserPriority)
Mapping to 802.11 Access Category (same as Wi-Fi WMM AC spec)
none
0
0
0
AC_BE
cs1
8
20
1
AC_BK
af11
10
28
1
AC_BK
af12
12
30
1
AC_BK
af13
14
38
1
AC_BK
cs2
16
40
2
AC_BK
af21
18
48
2
AC_BK
af22
20
50
2
AC_BK
af23
22
58
2
AC_BK
cs3
24
60
4
AC_VI
af31
26
68
4
AC_VI
af32
28
70
3
AC_BE
af33
30
78
3
AC_BE
cs4
32
80
4
AC_VI
af41
34
88
5
AC_VI
af42
36
90
4
AC_VI
af43
38
98
4
AC_VI
cs5
40
A0
5
AC_VI
va
44
B0
5
AC_VI
ef
46
B8
6
AC_VO
cs6
48
C0
6
AC_VO
cs7
56
E0
6
AC_VO