Abstract: The growing demand for content is straining the current Internet, and prompting the academic community to put forward several information centric future network architectures. These architectures transform the host-centric communication paradigm into content-centric. One of the most important features of Information Centric Networking（ICN） is to use in-network caching to reduce the delay of retrieving content, save network bandwidth and alleviate network congestion. Compared with the traditional Content Distribution Network（CDN）, Peer to Peer（P2P） and Web caching system, ICN caching system presents a series of new features. Firstly, the challenges of new caching features on the research of ICN are analyzed. Then, the optimization methods of cache in ICN are elaborated from various aspects, and the different cache strategies are analyzed and compared in detail. Finally, the future research directions are presented and the paper is concluded.

Key words: Information Centric Networking（ICN）, in-network caching, caching strategy

摘要： 因特网中日益增长的内容获取需求促使学术界提出了多种以信息为中心的未来网络架构。这类架构将以主机为中心的通信模式转变为以内容为中心。信息中心网络（ICN）最重要的特征之一是利用内置缓存减少用户获取内容的时延、节省网络带宽和缓解网络拥塞。与传统的内容分发网络（CDN）、对等网络（P2P）和Web缓存系统相比，ICN缓存系统呈现出一系列的新特征。分析了缓存新特征对ICN研究带来的挑战；从多方面重点阐述了ICN缓存的优化方法，详细分析对比了不同缓存策略；指出了未来研究方向并总结全文。

关键词: 信息中心网络, 内置缓存, 缓存策略