338
C
16: C
HAPTER
ONFIGURING
3
802.1p = 7
2
Tnl Hdr IP ToS = 0xe0
1
Srvc Type = 7 Voice Data . . .
Q
S
UALITY OF
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
IP ToS = 0xe0 Voice Data. . .
WX Switch A
Voice Data. . .
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
Layer 3
MAP A
MAP B
Voice
Video
Best Effort
Bgrnd
802.1p = 7
IP ToS = 0xe0 Voice Data. . .
Tnl Hdr IP ToS = 0xe0
Voice Data. . .
6
4
5