【摘要】：隨著計算機(jī)網(wǎng)絡(luò)技術(shù)的快速發(fā)展,網(wǎng)絡(luò)的規(guī)模不斷增大,網(wǎng)絡(luò)中的應(yīng)用與日俱增。如何滿足不斷增長的應(yīng)用業(yè)務(wù)的QoS要求,一直是研究熱點(diǎn),具有較大的研究價值和現(xiàn)實(shí)意義。區(qū)分服務(wù)網(wǎng)絡(luò)體系作為IETF提出的體系結(jié)構(gòu),具有簡單有效、擴(kuò)展性強(qiáng)的特點(diǎn),它采取邊緣分類、中心轉(zhuǎn)發(fā)的原則,順應(yīng)了網(wǎng)絡(luò)技術(shù)的發(fā)展趨勢,是未來高速網(wǎng)絡(luò)首選的方案。隊(duì)列管理和隊(duì)列調(diào)度技術(shù)作為區(qū)分服務(wù)體系中的核心技術(shù),是網(wǎng)絡(luò)中進(jìn)行資源管理、帶寬分配的關(guān)鍵。隊(duì)列管理技術(shù)和調(diào)度技術(shù)對網(wǎng)絡(luò)的QoS性能(吞吐率、丟包率、時延、時延抖動)有著巨大的影響�；诖�,本文在區(qū)分服務(wù)隊(duì)列算法的基礎(chǔ)上,提出了改進(jìn)的隊(duì)列管理和隊(duì)列調(diào)度算法。本文研究內(nèi)容及創(chuàng)新點(diǎn)如下:1介紹了區(qū)分服務(wù)網(wǎng)路QoS隊(duì)列算法的研究背景及其意義,分析了國內(nèi)外研究現(xiàn)狀,對網(wǎng)絡(luò)QoS的基本概念、性能指標(biāo)進(jìn)行了介紹,對區(qū)分服務(wù)網(wǎng)絡(luò)模型的基本概念、體系架構(gòu)進(jìn)行了研究,對網(wǎng)絡(luò)仿真工具NS2進(jìn)行了研究,剖析了其中的區(qū)分服務(wù)模型。2論文重點(diǎn)研究了區(qū)分服務(wù)模型下的隊(duì)列管理算法。通過對比典型的隊(duì)列管理算法,提出RIO-C算法適合于區(qū)分服務(wù)模型。針對RIO-C算法對分組丟棄過于直接、系統(tǒng)的利用率較低、對突發(fā)流量處理能力不足,本文提出了INRIO-C算法。該算法結(jié)合平均隊(duì)列長度與丟包率之間的非線性關(guān)系,考慮到網(wǎng)絡(luò)的實(shí)際擁塞情況,提出了分段的非線性的丟包方法,采取更加平滑的丟棄曲線來實(shí)現(xiàn)分組丟棄函數(shù)。通過在NS2.35仿真驗(yàn)證,INRIO-C算法有效地實(shí)現(xiàn)了AF隊(duì)列區(qū)分服務(wù)的要求,能夠保護(hù)較高優(yōu)先級業(yè)務(wù),同時在網(wǎng)絡(luò)負(fù)載較輕時減少丟包,提高了系統(tǒng)的利用率,在網(wǎng)絡(luò)負(fù)載較重時加大丟包,減緩擁塞。通過理論推導(dǎo)和仿真驗(yàn)證,算法有效地維持了隊(duì)列的穩(wěn)定性,高優(yōu)先級業(yè)務(wù)的丟包率和吞吐率均有增加。3論文重點(diǎn)研究了區(qū)分服務(wù)模型下的隊(duì)列調(diào)度算法。通過對比典型隊(duì)列調(diào)度算法,得出基于輪詢的隊(duì)列調(diào)度算法更加適合于區(qū)分服務(wù)網(wǎng)絡(luò)。本文在WRR算法的基礎(chǔ)上,針對其不能解決因分組長度不同引發(fā)的公平性問題,提出IFWRR算法,該算法結(jié)合隊(duì)列中的分組平均長度,合理改變權(quán)值,從而能夠更加公平地進(jìn)行帶寬的分配。通過仿真實(shí)驗(yàn)和理論分析,新算法在隊(duì)列的帶寬分配、公平性能方面能夠克服WRR算法的不足,滿足了帶寬實(shí)際分配的要求。
[Abstract]:With the rapid development of computer network technology, the scale of network is increasing, and the application of network is increasing day by day. How to meet the QoS requirements of the growing application business has been a hot research topic and has great research value and practical significance. As the architecture proposed by IETF, the differentiated service network has the characteristics of simple and effective, strong expansibility. It adopts the principle of edge classification and center forwarding, conforms to the development trend of network technology, and is the first choice of high-speed network in the future. Queue management and queue scheduling, as the core technologies of differentiated service system, are the key to resource management and bandwidth allocation in network. Queue management and scheduling technology have great influence on QoS performance (throughput, packet loss, delay jitter). Based on this, an improved queue management and queue scheduling algorithm is proposed on the basis of differentiated service queue algorithm. The research contents and innovations of this paper are as follows: 1 the research background and significance of QoS queue algorithm in DiffServ network are introduced, and the current research situation at home and abroad is analyzed. The basic concept and performance index of network QoS are introduced. In this paper, the basic concept and architecture of the differentiated service network model are studied, the network simulation tool NS2 is studied, and the differentiated service model is analyzed. 2 the queue management algorithm under the differentiated service model is mainly studied in this paper. By comparing the typical queue management algorithms, the paper proposes that the RIO-C algorithm is suitable for the differentiated service model. In view of the fact that the RIO-C algorithm is too direct for packet dropping, the utilization ratio of the system is low, and the ability to deal with burst traffic is insufficient, this paper proposes a INRIO-C algorithm. This algorithm combines the nonlinear relationship between the average queue length and the packet loss rate, considering the actual congestion of the network, a piecewise nonlinear packet loss method is proposed, and a smoother dropping curve is adopted to realize the packet dropping function. The simulation results in NS2.35 show that the INRIO-C algorithm can effectively meet the requirements of AF queue differentiated service, protect higher priority services, reduce packet loss when the network load is lighter, and improve the utilization rate of the system. Increase the loss of packets when the network load is heavy, reduce congestion. Through theoretical derivation and simulation, the algorithm effectively maintains the stability of the queue, and the packet loss rate and throughput rate of high-priority services are increased. 3 the queue scheduling algorithm based on the differentiated service model is studied in this paper. By comparing the typical queue scheduling algorithm, it is concluded that the polling based queue scheduling algorithm is more suitable for differentiated service networks. Based on the WRR algorithm, this paper proposes a IFWRR algorithm, which can not solve the fairness problem caused by the different packet length. The algorithm combines the average packet length in the queue to change the weights reasonably. Thus, the bandwidth can be allocated more fairly. Simulation experiments and theoretical analysis show that the new algorithm can overcome the shortcomings of WRR algorithm and meet the requirements of bandwidth allocation in terms of the fairness of queue bandwidth allocation.
【學(xué)位授予單位】：電子科技大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2014
【分類號】：TP393.09

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本文編號：2367304