【摘要】：隨著互聯(lián)網(wǎng)應(yīng)用技術(shù)的飛速發(fā)展,以網(wǎng)絡(luò)音／視頻為代表的流媒體業(yè)務(wù)早已成為Internet上最為流行的業(yè)務(wù)之一。與傳統(tǒng)業(yè)務(wù)相比,流媒體業(yè)務(wù)具有高流量、高并發(fā)、高敏感性等特征,如今P2P技術(shù)在流媒體業(yè)務(wù)上的應(yīng)用已在多個領(lǐng)域獲得成功。但國內(nèi)外對P2P流媒體傳輸協(xié)議的研究依然存在著諸多問題,如：P2P流媒體對傳輸?shù)腝oS保障力度不足、P2P覆蓋網(wǎng)絡(luò)中節(jié)點負(fù)載不均、P2P無法滿足ISP的流量策略、現(xiàn)存P2P傳輸機制應(yīng)對復(fù)雜網(wǎng)絡(luò)環(huán)境的能力不足。因此傳輸?shù)腝oS成為了P2P流媒體傳輸協(xié)議研究的重點問題。 本文在P2P流媒體概念的基礎(chǔ)上,詳細(xì)分析并對比了當(dāng)今P2P流媒體技術(shù)的優(yōu)劣勢,提出了P2P實時流媒體系統(tǒng)的總體設(shè)計,該設(shè)計是基于Mesh網(wǎng)絡(luò)的CDN-P2P混合網(wǎng)絡(luò)構(gòu)架,引入了強力節(jié)點、負(fù)載均衡服務(wù)器概念,實現(xiàn)了P2P流媒體系統(tǒng)中服務(wù)器節(jié)點與終端節(jié)點的負(fù)載均衡、網(wǎng)絡(luò)的擁塞控制,從而可以保證視頻服務(wù)質(zhì)量,滿足ISP的流量策略,為傳輸協(xié)議的優(yōu)化奠定了基礎(chǔ)。 由于傳統(tǒng)的PeerStreaming、ColdFusion的節(jié)點緩沖區(qū)管理能力不足,本文設(shè)計了新型緩沖區(qū)管理模型,緩沖區(qū)位圖矩陣(BMM,Buffer Map Matrix),用來表示對等節(jié)點與其相鄰節(jié)點的緩沖區(qū)中數(shù)據(jù)塊存在的狀態(tài)。 在緩沖區(qū)位圖矩陣的理論基礎(chǔ)上,本文設(shè)計了一種新型緩沖區(qū)動態(tài)管理策略。該策略主要用于對等節(jié)點剛進入系統(tǒng)時緩沖區(qū)窗口初始位置的確定與播放視頻過程中緩沖區(qū)窗口位置的動態(tài)調(diào)整。根據(jù)該策略設(shè)計并實現(xiàn)了一個動態(tài)緩沖區(qū)同步算法,通過實驗表明,該策略有效的利用了網(wǎng)絡(luò)帶寬,減少了傳輸延時,提高了系統(tǒng)整體的傳輸QoS。 針對目前P2P流媒體技術(shù)傳輸機制的不足,設(shè)計了一種新型基于推拉結(jié)合的傳輸機制。該機制按照數(shù)據(jù)塊的稀有率與節(jié)點問請求比來決定使用推機制或拉機制進行數(shù)據(jù)傳送。并在此基礎(chǔ)上設(shè)計并實現(xiàn)了推拉機制調(diào)節(jié)算法,該算法高效的減少了數(shù)據(jù)傳送延時,同時顯著的降低了數(shù)據(jù)傳送途中冗余數(shù)據(jù)的比率。
[Abstract]:With the rapid development of Internet application technology, streaming media service, represented by network audio / video, has become one of the most popular services on Internet. Compared with traditional services, streaming media services have the characteristics of high traffic, high concurrency, high sensitivity and so on. Nowadays, P2P technology has been successfully applied to streaming media services in many fields. However, there are still many problems in the research of P2P streaming media transmission protocol at home and abroad. For example, the QoS protection of P2P streaming media is not enough to meet the traffic policy of ISP in P2P overlay network. The existing P2P transmission mechanism has insufficient ability to deal with complex network environment. Therefore, QoS has become a key issue in P2P streaming media transmission protocol research. Based on the concept of P2P streaming media, this paper analyzes and compares the advantages and disadvantages of P2P streaming media technology in detail, and puts forward the overall design of P2P real-time streaming media system, which is a CDN-P2P hybrid network architecture based on Mesh network. The concept of strong node and load balancing server is introduced to realize load balance between server node and terminal node in P2P streaming media system and congestion control of network. Thus the quality of video service can be guaranteed and the traffic strategy of ISP can be satisfied. It lays a foundation for the optimization of transport protocol. Due to the deficiency of the traditional PeerStreamingColdFusion node buffer management capability, a new buffer management model is designed in this paper. The buffer bitmap matrix (BMMML-Buffer Map Matrix),) is used to represent the state of the data block in the buffer between the peer node and its adjacent node. Based on the theory of buffer bitmap matrix, a new buffer dynamic management strategy is designed in this paper. This strategy is mainly used to determine the initial position of buffer window when peer node first enters the system and to dynamically adjust the location of buffer window during video playback. According to this strategy, a dynamic buffer synchronization algorithm is designed and implemented. The experiments show that the strategy makes use of the network bandwidth effectively, reduces the transmission delay, and improves the overall transmission QoS of the system. Aiming at the shortage of P2P streaming media technology, a new transmission mechanism based on push-pull is designed. According to the rarity of data block and the ratio of node request, this mechanism decides to use push or pull mechanism to transmit data. On this basis, a push-pull mechanism adjustment algorithm is designed and implemented. The algorithm can effectively reduce the delay of data transfer and significantly reduce the ratio of redundant data on the way of data transmission.
【學(xué)位授予單位】：北京交通大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2014
【分類號】：TN919.8

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本文編號：2168105