ATM şebekelerinde veri trafiği yönetimi ve yığılma kontrolü
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Date
2002-04-20
Authors
Koçyiğit, İbrahim
Journal Title
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Volume Title
Publisher
Uludağ Üniversitesi
Abstract
Farklı servis kalitesi ihtiyaçlarına sahip kullanıcılara hizmet veren ATM şebekelerde trafik yönetimi ve yığılma kontrolü önemli bir meseledir. Bu tezin amacı, ATM şebekelerde trafik yönetim ve yığılma kontrol problemini analiz etmek, çözüm yaklaşımlarını ve önerilen teknikleri araştırmak ve değerlendirmektir. Çalışmanın ilk aşamasında, ATM şebekelerdeki tamponlarda kuyruklama ve düğümlerde anahtarlama analizleri gerçekleştirilmiştir. Bunun yanısıra, ATM şebekeye hücre geliş süreç modellemeleri de sunulmuştır. ATM şebekelerde trafik yönetim ve yığılma kontrol analizleri, çağrı kurma seviyesi zaman ölçeği ve hücre gönderme seviyesi zaman ölçeği olmak üzere iki farklı zaman ölçeğinde yapılabilir. İkinci aşama olarak, çağrı kurma seviyesi zaman ölçeğinde önemli bir kontrol mekanizması olan çağrı kabul kontrolü ( CAC ) ve yöneltim mekanizmaları incelenmiştir. Literatürde yer alan dört farklı CAC ve üç farklı yöneltim algoritmasının verimliliği park yeri şebeke topolojisi üzerinde simülasyonlarla incelenmiştir. Hücre gönderme seviyesindeki önemli kontrol mekanizmaları ise şebeke kaynak yönetimi, trafik şekilleme, trafik denetleme, öncelik kontrolü, hızlı kaynak yönetimi, seçerek hücre atma, hız ve kredi tabanlı yığılma kontrol fonksiyonlarıdır. Üçüncü aşama olarak, bu fonksiyonlar hücre seviyesinde analiz edilmiş ve çeşitli şebeke topolojilerinde simülasyonlarla verimlilik analizleri yapılmıştır. Ayrıca bu seviyede, ATM şebekede yüksek band genişliği isteyen TCP trafik ve diğer trafik (ses, görüntü vs.) olması durumunda ortaya çıkacak problemlerin çözümlenmesinde şekilleme, akış kontrolü, kuyruklama ve tamponlama analizleri yapılmıştır. Son aşamada, şebekede ABR trafik olduğu durumda ortaya çıkabilecek problemler için önerilmiş algoritmalardan biri olan hız tabanlı ERICA algoritması incelenmiş, ve simülasyonlarla verimlilik analizleri yapılmıştır. Daha sonra, ilk aşamada incelenmiş olan algoritmalardan çağrı seviyesi simülasyonlarıyla ön plana çıkmış olan MfCR algoritmasının verimliliği hücre seviyesi simülasyonlarıyla incelenmiştir.
Traffic management and congestion control is an important problem for ATM networks, which serve to users with different quality of service requirements. The goal of this thesis is to analyse traffic management and congestion control problem, to investigate and evaluate the solution approaches and the proposed techniques. In the first part of my thesis, the queuing analysis in ATM network buffers and the switching analysis at the nodes have been realised. Besides, the cell arriving process modelling has been presented. Traffic management and congestion control analysis in ATM networks can be done at two different time scales called the call set-up level time scale and the cell level time scale. In the second part, the call admission control and the routing mechanisms that are important at the call set-up time scale have been investigated. The efficiency of four different CAC and three different routing algorithms take place in the literature have been investigated over the parking lot network topology with simulations. The important control mechanisms at the cell level are network resources management, traffic shaping, traffic policing, priority control, fast resources management, selective cell discarding, rate and credit based congestion control functions. In the third part, these functions have been analysed at the cell level, and the efficiency analyses of them have been done in the various network topologies with simulations. Also shaping, flow control, queuing and buffering analyses have been done at the cell level to solve the problems that may arise in the network, in case both high bandwidth demanding TCP traffic and other type of traffic (voice, video etc.) exist in ATM network. At the last part of my thesis, the rate based ERICA algorithm which is one of the proposed algorithms for the problems of ABR traffic has been investigated, and the efficiency analyses of this algorithm have been done with simulations. Then one of the CAC algorithms, MfCR, which is also proved to be an efficient algorithm in call level simulations at the first part, has been investigated with cell level simulations.
Traffic management and congestion control is an important problem for ATM networks, which serve to users with different quality of service requirements. The goal of this thesis is to analyse traffic management and congestion control problem, to investigate and evaluate the solution approaches and the proposed techniques. In the first part of my thesis, the queuing analysis in ATM network buffers and the switching analysis at the nodes have been realised. Besides, the cell arriving process modelling has been presented. Traffic management and congestion control analysis in ATM networks can be done at two different time scales called the call set-up level time scale and the cell level time scale. In the second part, the call admission control and the routing mechanisms that are important at the call set-up time scale have been investigated. The efficiency of four different CAC and three different routing algorithms take place in the literature have been investigated over the parking lot network topology with simulations. The important control mechanisms at the cell level are network resources management, traffic shaping, traffic policing, priority control, fast resources management, selective cell discarding, rate and credit based congestion control functions. In the third part, these functions have been analysed at the cell level, and the efficiency analyses of them have been done in the various network topologies with simulations. Also shaping, flow control, queuing and buffering analyses have been done at the cell level to solve the problems that may arise in the network, in case both high bandwidth demanding TCP traffic and other type of traffic (voice, video etc.) exist in ATM network. At the last part of my thesis, the rate based ERICA algorithm which is one of the proposed algorithms for the problems of ABR traffic has been investigated, and the efficiency analyses of this algorithm have been done with simulations. Then one of the CAC algorithms, MfCR, which is also proved to be an efficient algorithm in call level simulations at the first part, has been investigated with cell level simulations.
Description
Keywords
ATM, QoS, CAC, TCP trafik şekilleme, ERICA, MfCR algoritması, TCP traffic shaping, MfCR algorithm
Citation
Koçyiğit, İ. (2002). ATM şebekelerinde veri trafiği yönetimi ve yığılma kontrolü. Yayınlanmamış doktora tezi. Uludağ Üniversitesi Fen Bilimleri Enstitüsü.