Cisco aironet 1522 Design And Deployment Manual page 110

Connecting the Cisco 1520 Series Mesh Access Point to Your Network
Figure 71
802.1p UP Outer IP DSCP Outer
For CAPWAP control traffic the IP DSCP value is set to 46, and the 802.1p user priority is set to 7. Prior
to transmission of a wireless frame over the backhaul, regardless of node pairing (RAP/MAP) or
direction, the DSCP value in the outer header is used to determine a backhaul priority. The following
sections describe the mapping between the four backhaul queues the mesh access point uses and the
DSCP values shown in Backhaul Path QoS
Table 16
DSCP Value
2, 4, 6, 8 to 23
26, 32 to 63
46 to 56
All others including 0
Note The platinum backhaul queue is reserved for CAPWAP control traffic, IP control traffic, and voice
packets. DHCP, DNS and ARP requests are also transmitted at the platinum QoS level. The mesh
software inspects each frame to determine whether it is an CAPWAP control or IP control frame in order
to protect the platinum queue from use by non-CAPWAP applications.
For a MAP to the client path, there are two different procedures, depending on whether the client is a
WMM client or a normal client. If the client is a WMM client, the DSCP value in the outer frame is
examined, and the 802.11e priority queue is used
Table 17
DSCP Value
2, 4, 6, 8 to 23
26, 32 to 45, 47
46, 48 to 63
All others including 0
If the client is not a WMM client, the WLAN override (as configured at the controller) determines the
802.11e queue (bronze, gold, platinum, or silver), on which the packet is transmitted.
For client towards mesh access point, there are modifications made to incoming client frames in
preparation for transmission on the mesh backhaul or Ethernet. For WMM clients, MAP illustrates the
way in which the outer DSCP value is set from an incoming WMM client frame.
Cisco Aironet 1520, 1130, 1240 Series Wireless Mesh Access Points, Design and Deployment Guide, Release 6.0
110
Controller to RAP Path
CAPWAP
Encapsulation Incoming 802.1p UP IP DSCP Inner
Backhaul Path QoS
MAP to Client Path QoS
(Table 16).
Backhaul Queue
Bronze
Gold
Platinum
Silver
(Table 17).
Backhaul Queue
Bronze
Gold
Platinum
Silver
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