【摘要】 现在的Internet架构存在众所周知的缺点,未来网络的研究成为了热点.其中,CCN(Content-Centric Networking)在众多新架构中正逐渐被大家认为是最有前途的方案.网络编码被认为是改善网络性能的一种有效方法,我们前期提出了CCN与网络编码相结合的CCN-NC(Content-Centric Networking with Built-in Network Coding)来进一步改善CCN的网络性能.覆盖全网的缓存系统成为了CCN网络内在固有的组成部分,但当前的分布式协作缓存技术由于额外的通信开销大或技术复杂依然不能大规模实用,而非协作缓存技术的缓存效率又不高.在本文中,首先为缓存效率的分析建立模型,对CCN和CCN-NC的缓存效率进行了理论分析和仿真,同时,文件大小,备份数量,替换概率等参数对缓存效率的影响也被全面地研究.本文从理论上证明:在相同的参数下,相比于CCN,CCN-NC依靠网络编码可以改善网络缓存效率,仿真结果也验证了这一结论.更多还原

【Abstract】 To address lots of challenges of current Internet,a clean-slate architecture design paradigm has been suggested to build the future Internet by the research community. As one of many novel network architectures for future Internet,CCN( Content-Centric Networking) is increasingly being accepted as the most promising architecture. Network coding is considered as the most promising information theoretic approaches to improve performance in current Internet. Our previous work has proposed CCN-NC( ContentCentric Networking built Network Coding) to further improve network performance of CCN. Caching system will be the inherent part of CCN,and cooperative in-network caching is yet so far because of the complexity and practicality of technology. However,caching efficiency of uncooperative caching system is disappointed. In this paper,we construct a model to analyze caching efficiency. We compared the caching efficiency between the original CCN and CCN-NC both analytically and by simulations. Impact of different parameters on caching efficiency,such as file size,copy size and probability of replacement etc.,are also extensively researched. We prove theoretically that network coding help CCN-NC to improve caching efficiency compared to CCN under the same conditions,and this is also confirmed by simulation result.更多还原