3Com WX4400 3CRWX440095A - Manual (Page 338)

338 C HAPTER 16: C ONFIGURING Q UALITY OF S ERVICE
(To display a MAP’s CoS mappings and queue usage statistics, see
“Displaying MAP Forwarding Queue Statistics” on page 349.)
Figure 28 shows an example of end-to-end QoS in a 3Com network. In
this example, voice traffic is prioritized based on WMM. This example
assumes that the QoS mappings are set to their default values.
Figure 28 WMM QoS in a 3Com Network
Figure 28 shows the following process:
1 A user sends voice traffic from a WMM VoIP phone. The phone marks the
CoS field of the packet with service type 7, indicating that the packet is
for high priority (voice) traffic.
2 MAP A receives the voice packet and classifies the packet by mapping the
service type in the 802.11 header to an internal CoS value. In this
example, the service type is 7 and maps to internal CoS 7.
Layer 3
WX Switch B
Srvc Type = 7 Voice Data . . .
IP ToS = 0xe0 Voice Data. . . 802.1p = 7 IP ToS = 0xe0 Voice Data. . . 802.1p = 7
Voice
Video
Best Effort
Bgrnd
WX Switch A
4
1
2
3
5
6
Voice Data. . . Tnl Hdr IP ToS = 0xe0
Voice Data. . . Tnl Hdr IP ToS = 0xe0
Layer 3
MAP A MAP B