88
Figure 33 CNM PDU format
How QCN works
shows how QCN works.
•
The CP periodically samples frames from QCN-enabled queues and sends CNMs to the RPs
when congestion occurs.
•
The RPs reduce their transmission rates when receiving CNMs. The RPs also periodically
probe the bandwidth and increase their transmission rates if they fail to receive CNMs for a
specific period of time.
Figure 34 How QCN works
Version
Encapsulated priority
cnmQDelta
cnmQOffset
Congestion Point Identifier (CPID)
Quantized Feedback
ReservedV
Encapsulated MSDU
Encapsulated MSDU length
Encapsulated destination MAC address
Octet
Length
1
4 bits
1, 2
6 bits
2
6 bits
3
8
11
2
13
2
15
2
17
6
23
2
25
0
–
64
Summary of Contents for FlexFabric 5940 Series
Page 23: ...17 Figure 3 QoS processing flow ...
Page 84: ...78 Figure 26 MPLS label structure ...
Page 91: ...85 Switch burst mode enable ...