Modeling and simulation of ATM congestion

Dissertant

Abbas, Arij Hamid

University

University of Technology

Faculty

-

Department

Computer Sciences Department

University Country

Iraq

Degree

Master

Degree Date

2004

English Abstract

In an Asynchronous Transfer Mode (ATM) network, the traffic management is a very important matter that tries to make each user gets the required level of Quality of Service (QoS) for his traffic stream for all ATM service classes.

The "congestion control is an essential part of traffic management, to make the latter as 5 efficient as possible.

So in this thesis selected switching techniques for congestion control are modeled and simulated.

Reasons behind those selections are also described. This research is concerned with the modeling and simulating of ATM switching techniques for controlling the congestion state at the network's switches.

These switching techniques include Connection Admission Control (CAC) for Constant Bit Rate (CBR) and Variable Bit Rate (VBR) service classes.

Due to the bursty nature for the Available Bit Rate (ABR) service class and to allocate the network resources as efficiently as possible, other switching techniques, including Enhanced Proportional Rate Control Algorithm (EPRCA), Explicit Rate Indication for Congestion Avoidance (ERICA) and Congestion Avoidance using Proportional Control (CAPC), were used as well as CAC at the connection setup was applied, Four models are taken into consideration in this work, one for each congestion control switching technique.

So it contains a model for (CAC) technique, which prevents the congestion from occurring from the first time at the set up phase, and it is used for CBR and VBR service class.

The remaining models are used to control the congestion in ABR service class.

Each network model contains four ATM switches, which were simulated to use the Virtual Path (VP) switching technique, and ten users for each side of the network.

Any user has the ability to open more than one Virtual Channel (VC) with the required destination at the same time depending on its own link's band width and on the required rate of sending for those VCs. The performance analysis for ABR congestion control-switching techniques was implemented.

The performance for each technique had been analyzed with respect to changing several control parameters and monitoring their effects on the propagation delay and the Cell Loss Ratio (CLR) for each connection.

The analysis results are used to determine the weakness region in the congestion processing of each technique, and if that weakness is acceptable or not for both network and the end users.

Performance comparison between congestion control-switching techniques is made to specify the efficient one. Visual Basic (V6)-programming language is used for coding the congestion control algorithms used in simulation process.

Main Subjects

Electronic engineering

• APA
• MLA
• AMA

Language

English

Data Type

Arab Theses

Record ID

BIM-305564