Priority Marking
local precedence.
Traf
rs. For example, traffic can be limited to get
o avoid network congestion caused by excessive
to limit the traffic and the resource occupied by
emented according to the evaluation result on the
cification when traffic policing is performed.
th a certain capacity to hold tokens. The system
ken bucket is full, the extra tokens will overflow
ng.
The priority marking function is to reassign priority for the traffic matching an ACL referenced for traffic
classification.
z
If 802.1p priority marking is configured, the traffic will be mapped to the local precedence
corresponding to the re-marked 802.1p priority and assigned to the output queue corresponding to
the
z
If local precedence marking is configured, the traffic will be assigned to the output queue
corresponding to the re-marked local precedence.
z
If IP precedence or DSCP marking is configured, the traffic will be marked with new IP precedence
or DSCP precedence.
fic Policing
The network will be made more congested by plenty of continuous burst packets if the traffic of each
user is not limited. The traffic of each user must be limited in order to make better use of the limited
network resources and provide better service for more use
only its committed resources during a time period t
bursts.
Traffic policing is a kind of traffic control policy used
supervising the traffic. The regulation policy is impl
premise of knowing whether the traffic exceeds the spe
Normally, token bucket is used for traffic evaluation.
Token bucket
The token bucket can be considered as a container wi
puts tokens into the bucket at the set rate. When the to
and the number of tokens in the bucket stops increasi
Figure 45-5
Evaluate the traffic with the token bucket
E
determines the amount of the packets that can be forwarded. If the number of tokens in the bucket is
valuating the traffic with the token bucket
When token bucket is used for traffic evaluation, the number of the tokens in the token bucket
45-8
