RSS
Twitter
Facebook
* WFQ addresses the situation in which different users have different
requirements.
* Each user flow has its own buffer and each user flow also has weight.
* Here weight determines its relative bandwidth share.
* If buffer 1 has weight 1 and buffer 2 has weight 3, then when both
buffers are nonempty, buffer 1 will receive 1/(1+3)=1/4 of the bandwidth and
buffer 2 will receive ¾ of the bandwidth.
.PNG)
In the above
figure,
* In Fluid-flow
system, the transmission of each packet from buffer 2 is completed at time
t=4/3, and the packet from buffer 1 is completed at t=2 seconds.
* In the above
figure buffer1 would receive 1 bit/round and buffer 2 would receive 3 bits/second.
* Packet-by-packet
weighted fair queueing calculates its finishing tag as follows
F(i,k,t) =
max{F(i,k-1,t), R(t)} + P(i,k,t)/wi
* The above
figure also shows the completion times for Packet-by-packet weighted fair queueing.
* The finish tag
for buffer1 is F(1,1)=R(0)+1/1 =1 and finish tag for buffer 2 is
F(2,1) =R(0) +
1/3 =1/3.
* Therefore the
packet from buffer 2 is served first and followed by packet from
buffer 1.
0 comments