الفهرس 
Chapter 1: IntroductionOnly 14 pages are availabe for public view
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Abstract
Recently, the Internet became the most important environment for
many activities including emails, phone calls and videoconferences.
Nevertheless, the incremental growth of the internet traffic leads to a
serious problem called congestion. Several Active Queue Management
(AQM) algorithms have been developed at the internet routers to
avoid congestion before happening and solve the congestion if it
happens by actively controlling the average queue length in the
routers. However, most of the developed algorithms handle all the
internet traffics by the same strategy although the internet traffics,
real time and non-real time, require different Quality of Service (QoS).
This problem may lead to performance degradation especially for realtime
applications as video and audio traffics.
This thesis first presents a performance evaluation of the current AQM
algorithms. It then presents a new (class-based dynamic scheduling
strategy) AQM algorithm, called Dynamic Queue RED (DQRED), to
guarantee efficient QoS to both real-time and non-real-time traffics. In
the proposed algorithm, three queues are used in the internet router;
one queue for each traffic type (data, audio and video). The arrived
packets are first queued in the corresponding queue. The queued
packets are then scheduled dynamically according to the load (the
number of queued packets) of each class type. This strategy
guarantees QoS for real time applications as well as service fairness.
Finally, a comparative study is done between the proposed DQRED
algorithm and the most recent AQM algorithms by using the network
simulator (NS-2) considering different QoS Metrics.