Analysis and Simulation of a Fair Queueing Algorithm

Motivation: This paper presents a Fair Queuing Algorithm and shows its
applicability to efficient congestion avoidance as well as to allocate
bandwidth, promptness and buffer space independently.

Key Points:

1) This paper took a view of the interplay between the source flow
control, gateway routing and gateway queuing policies together as a whole.

2) The fair allocation is ensured by simulating a bit-by-bit round robin
algorithm on a packet-by-packet round robin basis. Packets are taken
from a queue (maintained for each user) in a pseudo bit-by-bit
round-robin pattern. The round-robin is done by keeping track of the
current "round" of transmission and transfer the packet with the
smallest finishing "round" number.
 3) The promptness is ensured by introducing a little bit of history -
the finish round of last packet - FQ can give more promptness to users
who utilize less than their fair share of bandwidth, which is important
to interactive applications like remote login. This is further refined
by introducing a new parameter to control sensitivity.

4) They suggest that insufficient window sizes may result in unfair
allocations. Thus, fair queuing gateways themselves cant provide
adequate congestion control, they must be combined with intelligent flow
control algorithms at the sources. In particular combination of FQ
gateways and DECbit flow control was particularly effective.

5) I was compelled to think what if there is a misbehaving gateway?
Although, its beyond the scope of the paper but it raised my curiosity
to analyze if its possible to curb (limit) the disturbance caused by a
misbehaving gateway as well.

Lesson Learnt : Theory beholds the answer to many mysteries.
Received on Thu Sep 28 2006 - 07:26:39 EDT