Traffic Management and Congestion Control in the ATM Network Model.

Asynchronous Transfer Mode (ATM) networking technology has been chosen by the International Telegraph and Telephony Consultative Committee (CCITT) for use on future local as well as wide area networks to handle traffic types of a wide range. It is a cell based network architecture that resembles circuit switched networks, providing Quality of Service (QoS) guarantees not normally found on data networks. Although the specifications for the architecture have been continuously evolving, traffic congestion management techniques for ATM networks have not been very well defined yet. This thesis studies the traffic management problem in detail, provides some theoretical understanding and presents a collection of techniques to handle the problem under various operating conditions. A detailed simulation of various ATM traffic types is carried out and the collected data is analyzed to gain an insight into congestion formation patterns. Problems that may arise during migration planning from legacy LANs to ATM technology are also considered. We present an algorithm to identify certain portions of the network that should be upgraded to ATM first. The concept of adaptive burn-in is introduced to help ease the computational costs involved in virtual circuit setup and tear down operations

Analysis Of Pram Instruction Sets From A Log Cost Perspective

The log cost measure has been viewed as a more reasonable method of measuring the time complexity of an algorithm than the unit cost measure. The more widely used unit cost measure becomes unrealistic if the algorithm handles extremely large integers. Parallel machines have not been examined under the log cost measure. In this paper, we investigate the Parallel Random Access Machine under the log cost measure. Let the instruction set of a basic PRAM include addition, subtraction, and Boolean operations. We relate resource-bounded complexity classes of log cost PRAMs to complexity classes of Turing machines and circuits. We also relate log cost PRAMs with different instruction sets by simulations that are much more efficient than possible in the unit cost case. Let LCRCW k (CRCW k ) denote the class of languages accepted by a log cost (unit cost) basic CRCW PRAM in O(log k n) time with polynomial in n number of processors. We position the log cost PRAM in the hierarchy of paralle..

Bandwidth Allocation Problem in ATM Network Model is NP-Complete

We show that the Bandwidth Allocation problem in the ATM network model is NPComplete. Based on that inference we suggest using the Genetic Algorithm technique to select a subset of calls from the set of incoming call requests for transmission, so that the available network bandwidth is utilized effectively, thus maximizing the revenue generated while preserving the promised QoS. Keywords: ATM, NP-Complete, Genetic Algorithm 1 Introduction The Asynchronous Transfer Mode (ATM) Network Model has been evolving as the standard for future networking that is expected to carry voice, real time video and a large volume of still images in addition to the growing volumes of computer data. ATM networks are predominently expected to be implemented using optical fiber with very low data error rate and guaranteed Quality of Service (QoS). It works on the assumption that the required bandwidth for transmission will be available throughout the connection time; the QoS deteriorates drastically when the..