本文選題：服務質(zhì)量 + 綜合服務　； 參考：《電子科技大學》2014年碩士論文

【摘要】：在網(wǎng)絡信息高速發(fā)展的時代,網(wǎng)絡多媒體業(yè)務不斷涌現(xiàn),網(wǎng)絡用戶越來越多地提出包括多媒體業(yè)務通信在內(nèi)的綜合服務要求。傳統(tǒng)分組交換網(wǎng)數(shù)據(jù)傳輸多面向?qū)崟r性要求不高的數(shù)據(jù)通信(如FTP和Email等),采用TCP/IP協(xié)議主要為了優(yōu)化網(wǎng)絡業(yè)務流吞吐量并保證其通信可靠性。而現(xiàn)今網(wǎng)絡是處于多種業(yè)務流并存的狀態(tài),其中包括一些實時性較強的多媒體應用,例如VoIP等。這些應用不僅包括文本信息,而且還包括語音(Voice)、圖形(Graphic)、視頻(Video)等形式的信息。這些信息在傳輸時不僅要求網(wǎng)絡具有較高的帶寬保證,同時要求具有傳輸?shù)脱舆t、低抖動和低錯誤率等性能。由此可見,在網(wǎng)絡不斷發(fā)展的情況下,新興業(yè)務流特別是對實時性較高的多媒體應用對網(wǎng)絡提出了更高的服務質(zhì)量(Quality of Service,QoS)需求,需要網(wǎng)絡提供更加有效的QoS控制和保證。有鑒于此,本文將對QoS優(yōu)化技術(shù)進行研究。本文核心旨在對QoS網(wǎng)絡技術(shù)中的關(guān)鍵技術(shù)——隊列調(diào)度算法進行研究和優(yōu)化。在文中通過對比研究分析常見隊列調(diào)度算法,選擇公平性較好的加權(quán)公平隊列(Weighted Fair Queuing,WFQ)調(diào)度算法進行深入地研究,并在研究分析基礎(chǔ)上根據(jù)其不支持實時性業(yè)務流的缺點提出改進方案。在實施改進方案中形成三種改進模型:基于權(quán)值改進的加權(quán)公平隊列調(diào)度算法、基于優(yōu)先級保證帶寬的加權(quán)公平隊列調(diào)度算法以及將兩種相結(jié)合的支持實時業(yè)務的加權(quán)公平隊列調(diào)度算法。最終經(jīng)過NS-2網(wǎng)絡仿真器在時延、吞吐量和丟包率QoS參數(shù)方面進行仿真,通過仿真分析表明:三種改進模型都能使加權(quán)公平隊列調(diào)度算法很好地支持實時業(yè)務流。本論文是以先研究分析后提出改進方案為思路。在本文中首先對QoS網(wǎng)絡應用背景進行闡述,然后對QoS網(wǎng)絡技術(shù)發(fā)展過程中的主要模型作研究,這包括最大努力模型、綜合服務模型、區(qū)分服務模型,對這三種模型先研究分析其原理與結(jié)構(gòu),分析優(yōu)缺點,然后研究目前因特網(wǎng)所應用的主要服務模型及其關(guān)鍵技術(shù)�；谏鲜鰧δ壳皯幂^廣泛的典型隊列調(diào)度算法進行研究,并分析其優(yōu)缺點。相繼深入研究加權(quán)公平隊列調(diào)度算法并提出改進方案,然后根據(jù)改進方案利用NS-2網(wǎng)絡仿真軟件進行模擬仿真,并對比分析改進算法與未改進算法仿真結(jié)果,最終通過仿真分析得到改進算法比原有算法在支持實時業(yè)務流方面得到了很大改善。
[Abstract]:In the era of rapid development of network information, network multimedia services continue to emerge, network users increasingly put forward comprehensive service requirements, including multimedia service communications. The traditional packet switching network data transmission is oriented to the data communication (such as FTP and Email, etc.) which does not require high real-time performance. The TCP/IP protocol is mainly used to optimize the throughput of network traffic and ensure its communication reliability. Nowadays, the network is in the state of multiple traffic, including some real-time multimedia applications, such as VoIP and so on. These applications include not only text information, but also voice, graphics, video and other forms of information. The transmission of these information requires not only high bandwidth guarantee, but also low transmission delay, low jitter and low error rate. It can be seen that with the continuous development of the network, the new traffic, especially for the multimedia applications with high real-time performance, puts forward a higher quality of service (QoS) requirement for the network, which requires the network to provide more effective QoS control and guarantee. In view of this, this paper will study the QoS optimization technology. The core of this paper is to research and optimize queue scheduling algorithm, which is the key technology of QoS network. In this paper, by comparing and analyzing common queue scheduling algorithms, we select weighted Fair queuing WFQs with better fairness to do in-depth research. On the basis of research and analysis, an improved scheme is put forward according to its shortcoming of not supporting real-time traffic. In the implementation of the improved scheme, three kinds of improved models are formed: weighted fair queue scheduling algorithm based on weight improvement, A weighted fair queue scheduling algorithm based on priority guaranteed bandwidth and a weighted fair queue scheduling algorithm which combines the two algorithms to support real-time traffic are proposed. Finally, the NS-2 network simulator is used to simulate the delay, throughput and packet loss rate QoS parameters. The simulation results show that the three improved models can make the weighted fair queue scheduling algorithm support real-time traffic very well. This paper is based on the research and analysis, and then put forward the improvement plan as the train of thought. In this paper, the application background of QoS network is first expounded, and then the main models in the development of QoS network technology are studied, which include the best effort model, the integrated service model, the differentiated service model. First, the principle and structure of the three models are analyzed, and then the main service models and their key technologies used in the Internet are studied. Based on the above, the typical queue scheduling algorithms, which are widely used at present, are studied, and their advantages and disadvantages are analyzed. The weighted fair queue scheduling algorithm is studied in succession and an improved scheme is put forward. According to the improved scheme, the NS-2 network simulation software is used to simulate and simulate, and the simulation results of the improved algorithm and the unimproved algorithm are compared and analyzed. Finally, the simulation results show that the improved algorithm is much better than the original algorithm in supporting real-time traffic.
【學位授予單位】：電子科技大學
【學位級別】：碩士
【學位授予年份】：2014
【分類號】：TP393.06

【參考文獻】

相關(guān)碩士學位論文 前1條

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