NDN中任播机制的研究与实现

发布时间：2019-01-19 16:50

【摘要】：目前,用户对互联网的访问模式已经从点对点通信为主转为内容获取为主。传统的TCP/IP网络仅传输字节流,并不感知内容,从而造成了网络上大量的冗余流量传输。此外,信息科技的不断发展,特别是移动互联网的迅猛发展,使得网络流量日益增大,网络应用呈现多样化的特点,网络管理也变得越来越复杂,使现有网络在可扩展性、安全性、可管可控性以及移动性等方面均面临诸多挑战。当前的网络架构已经难以满足网络应用的未来发展需求,为了解决当前互联网面临的挑战,研究界提出了信息中心网络这一革命性解决方案,命名数据网络(Named Data Networking, NDN)是其中的一个典型代表。作为一种新型网络架构,NDN不仅要能够有效应对现有网络面临的挑战,从根本上解决网络流量的爆炸性增长问题,而且需要支持现有互联网服务的运营模式。为了应对海量的用户,许多大型互联网服务都采用了任播服务架构,基于DNS或重定向等技术由众多物理上分散的服务器或者服务器集群为不同用户提供服务,以提高服务的可扩展性、可靠性及高可用性。但是,TCP/IP网络与NDN在网络架构上的巨大差异使得现有的互联网任播机制无法直接移植到NDN网络中,而NDN自身基于路由的任播机制无法满足有状态和灵活的任播需求。本文针对NDN不支持灵活和有状态的任播需求这一问题,提出了基于请求重定向、报文重写和基于混合机制的任播解决方案,并对不同方案进行了系统的分析比较。本文的主要贡献如下:1)全面分析了任播服务的特性和应用场景及NDN与TCP/IP网络架构的差异,指出TCP/IP的任播机制无法直接移植到NDN网络中的原因,及NDN中支持任播所面临的挑战。2)围绕有状态和灵活的任播需求,提出了 NDN中的多种任播解决方案,并从可扩展性(Scalability)、流亲近性(Flow Affinity)、透明性(Transparency)、灵活性(Flexibility)及服务响应时间等度量标准对不同方案进行了系统的比较分析。定性的分析结果表明,基于混合机制的任播方案在各方面均有较好的表现,能有效满足有状态和灵活的任播需求。3)针对重定向-重写的混合任播机制,提出了多种第一预设策略和第二预设策略。基于OMNet++仿真平台和ccnSim,完成了系统设计和仿真实现,验证了系统的正确性,并对不同组合策略的性能进行了评价。
[Abstract]:At present, the access mode of users to the Internet has changed from point-to-point communication to content acquisition. Traditional TCP/IP networks only transmit byte streams and do not perceive content, which results in a large number of redundant traffic on the network. In addition, with the continuous development of information technology, especially the rapid development of mobile Internet, network traffic is increasing day by day, network applications are diversified, and network management is becoming more and more complex, which makes the existing network extensible. Security, controllability and mobility face many challenges. The current network architecture has been difficult to meet the needs of the future development of network applications. In order to solve the current challenges facing the Internet, the research community has put forward the information center network, a revolutionary solution, named data network (Named Data Networking,. NDN) is one of the typical representatives. As a new network architecture, NDN not only has to be able to effectively deal with the challenges faced by the existing network, fundamentally solve the explosive growth of network traffic, but also need to support the operation mode of the existing Internet services. In order to cope with a large number of users, many large Internet services have adopted the architecture of anycast services. Based on DNS or redirection and other technologies, many physically dispersed servers or server clusters provide services to different users. To improve service scalability, reliability and high availability. However, the huge difference between TCP/IP network and NDN in network architecture makes the existing Internet anycast mechanism can not be directly transplanted to NDN network, and the NDN routing based anycast mechanism can not meet the need of stateful and flexible anycast. In order to solve the problem that NDN does not support flexible and stateful demand for any broadcast, this paper proposes a solution based on request redirection, message rewriting and hybrid mechanism, and makes a systematic analysis and comparison of different schemes. The main contributions of this paper are as follows: 1) the characteristics and application scenarios of anycast service and the differences between NDN and TCP/IP network architecture are analyzed, and the reasons why TCP/IP 's broadcast mechanism can not be directly transplanted to NDN network are pointed out. And the challenge of supporting any broadcast in NDN. 2) focusing on the requirement of any broadcast with state and flexibility, this paper puts forward a variety of solutions in NDN, and makes (Flow Affinity), transparent from extensible (Scalability), stream. Flexible (Flexibility) and service response time are used to compare and analyze the different schemes. The qualitative analysis results show that the hybrid scheme has a good performance in all aspects and can effectively meet the needs of any broadcast with state and flexibility. 3) for the redirection-rewriting hybrid anycast mechanism, Several first and second presupposition strategies are proposed. Based on the OMNet simulation platform and ccnSim, the system design and simulation are completed, the correctness of the system is verified, and the performance of different combination strategies is evaluated.
【学位授予单位】：南京师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TP393.0

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