3com 3CRWXR10095A Manual De Usuario

MSS supports Layer 2 and Layer 3 classification and marking of traffic, to 
help provide end-to-end QoS throughout the network. QoS support 
includes support of Wi-Fi Multimedia (WMM), which provides wireless 
QoS for time-sensitive applications such as voice and video. 

QoS support is automatically enabled. WX switches and MAPs each 
provide QoS:

„

WX switches classify and mark traffic based on 802.1p tag value (for 
tagged traffic) or Differentiated Services Code Point (DSCP) value. 

„

MAPs classify ingress traffic from wireless clients based on the service 
type value in the 802.11 header, and mark the DSCP value in the IP 
tunnel on which the MAP forwards the user traffic to the WX. 

MAPs place traffic from a WX to a wireless client in a forwarding 
queue based on the DSCP value in the tunnel carrying the traffic, then 
forward the traffic based on the queue’s priority.

MSS 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. 

(For more information about how MSS QoS works, see the “Configuring 
Quality of Service” chapter in the 

To view CoS mappings:

1 Select the Configuration tool bar option.

2 In the Organizer panel, click the plus sign next to the WX switch. 

3 Click the plus sign next to System.

4 Select QoS.