3com 5500-ei pwr Instrução De Instalação

 

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peak will then occur in a certain future time. Consequently, the network traffic jitters all the 

time.  

You can use weighted random early detection (WRED) to avoid global TCP session 

synchronization.  

In WRED algorithm, an upper limit and a lower limit are set for each queue, and the packets 

in a queue are processed as follows.  

z 

When the current queue length is smaller than the lower limit, no packet is dropped;  

z 

When the queue length exceeds the upper limit, all the newly received packets are 

dropped;  

z 

When the queue length is between the lower limit and the upper limit, the newly 

received packets are dropped at random. The longer the queue, the more likely the 

newly received packets may be dropped. However, a maximum drop probability exists.   

In WRED, random numbers are generated to determine the packets to be dropped. As the 

dropping policy is determined by IP precedence, packets with lower precedence are more 

likely to be dropped.  

WRED prevents global TCP session synchronization. It enables other TCP sessions to be 

free of a TCP session slowed down because of its packets being dropped. In this way, TCP 

sessions can operate in different rates in any case and the link bandwidth can be fully 

utilized.  

The function of flow-based traffic accounting is to use ACL rules in traffic classification and 

perform traffic accounting on the packets matching the ACL rules. You can get the statistics 

of the packets you are interested in through this function. 

The Burst function can provide better packet cache function and traffic forwarding 

performance. It is suitable for networks where 

z 

Large amount of broadcast/multicast packets and large burst traffic exist. 

z 

Packets of high-rate links are forwarded to low-rate links or packets of multiple links 

with the equal rates are forwarded to a single link that is of the same rate as that of the 

incoming links. 

Although the burst function helps reduce the packet loss ratio and improve packet 

processing capability in the networks mentioned above, it may affect QoS performance. So, 

use this function with caution.