Nortel 2360 Configuration Manual page 353

WMM QoS on the WSS
WSS Software performs classification on ingress to determine a packet's CoS value. This CoS value is used to mark the
packet at the egress interface.
The classification and marking performed by the switch depend on whether the ingress interface has an 802.1p or DSCP
value other than 0, and whether the egress interface is tagged or is an IP tunnel.
The mappings between DSCP and CoS values are configurable. (See
and CoS values map directly and are not configurable. DSCP 0 of the DSCP-to-CoS map is reserved. 802.1p determines
CoS for packets with DSCP 0. CoS 0 of the CoS-to-DSCP map is also reserved. CoS 0 packets are marked with DSCP 0.
Table 4 shows how WMM priority information is mapped across the network. When WMM is enabled, Nortel switches
and APs perform these mappings automatically.
Service
IP Precedence IP ToS
Type
0 0
3 3
1 1
2 2
4 4
5 5
6 6
7 7
You can use static CoS to assign the same CoS value to all packets for a specific SSID. The static CoS value is assigned
on the AP, in both traffic directions (from the client to the WSS and from the WSS to the client). (For information, see
"Configuring static CoS" (page
You also can use ACLs to override marking for specific packets. Configure ACEs that use the dscp option to match on
ingress DSCP value, and use the cos option to mark CoS. A CoS value assigned by an ACE overrides the internal CoS
value. (For information, see
WMM QoS on an AP
APs use forwarding queues to prioritize traffic for wireless clients.
For a packet received by the AP from a client, the AP classifies the packet based on the service type in the 802.11 header
and maps the service type value to an internal CoS value. The AP then marks the DSCP value in the IP tunnel header to
the WSS based on the internal CoS value.
For a packet received from a WSS and addressed to a client, the AP classifies the packet by mapping the DSCP value in
the IP tunnel header to an internal CoS value. The AP then assigns the packet to a forwarding queue based on the internal
CoS value. The AP also marks the service type in the 802.11 header based on the internal CoS value.
Table 4.WMM Priority Mappings
0
0x60
0x20
0x40
0x80
0xa0
0xc0
0xe0
360).)
"Using ACLs to change CoS" (page
Nortel WLAN—Security Switch 2300 Series Configuration Guide
Configuring quality of service 353
"Changing CoS mappings" (page
DSCP 802.1p CoS
0 0 0
24 3 3
8 1 1
16 2 2
32 4 4
40 5 5
48 6 6
56 7 7
431).)
360).) 802.1p
AP
Forwarding
Queue
Background
Best Effort
Video
Voice