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Cisco Aironet 1520, 1130, 1240 Series Wireless Mesh Access Points, Design and Deployment Guide, Release 6.0
OL-20213-01
Connecting the Cisco 1520 Series Mesh Access Point to Your Network
Figure 72
MAP to RAP Path
The minimum of the incoming 802.11e user priority and the WLAN override priority is translated using
the information listed in
to determine the DSCP value of the IP frame. For example, if the
incoming frame has as its value a priority indicating the gold priority, but the WLAN is configured for
silver priority, the minimum priority of silver is used to determine the DSCP value.
In the event that there is no incoming WMM priority, the default WLAN priority is used to generate the
DSCP value in the outer header. In the event that the frame is an originated CAPWAP control frame, the
DSCP value of 46 is placed in the outer header.
With the 5.2 code enhancements, DSCP information is preserved in AWPP header.
All wired client traffic is restricted to a maximum 802.1p UP value of 5, except DHCP/DNS and ARP
packets, which goes through the platinum queue.
The non-WMM wireless client traffic gets the default QoS priority of its WLAN. While, the WMM
wireless client traffic may have maximum 802.11e value of 6, but they must be below the QoS profile
configured for its WLAN. If admission control is configured, WMM clients must use TSPEC signaling
and get admitted by CAC.
The CAPWAPP data traffic carries wireless client traffic and hence has the same priority and treatment
as wireless client traffic.
Now that the DSCP value is determined, the rules described earlier for the backhaul path from RAP to
MAP are used to further determine the backhaul queue on which the frame is transmitted. Frames
transmitted from the RAP to the controller are not tagged. The outer DSCP values are left intact, as they
were first constructed.
Bridging Backhaul Packets
Bridging services are treated a little differently from regular controller-based services. There is no outer
DSCP value in bridging packets because they are not CAPWAP encapsulated. Therefore, the DSCP value
in the IP header as it was received by the mesh access point is used to index into the table as described
in the path from mesh access point to mesh access point (backhaul).
205689
IP DSCP O
u
ter
CAPWAP
Encaps
u
lation
Incoming 802.11e UP IP DSCP Inner
Table 18
DSCP to Backhaul Queue Mapping
DSCP Value
802.11e UP
Backhaul Queue
Packet Types
2, 4, 6, 8 to 23
1, 2
Bronze
Lowest priority packets, if any
26, 32 to 34
4, 5
Gold
Video packets
46 to 56
6, 7
Platinum
CAPWAP control, AWPP,
DHCP/DNS, ARP packets, voice
packets
All others including 0
0, 3
Silver
Best effort, CAPWAP data
packets