| Recently, media streaming and multimedia content sharing applications appear.New applications are more concerned about the content itself, and do not care about the storage location, but present TCP/IP 's host-oriented communication model does not adapt to this change leads to explosive growth of network traffic. The research community proposed the Information Centric Networking (ICN), which treats information as the first-class citizen of the network, uses content name for identification and routing, and takes advantage of ubiquitous in network caching, flexible routing and forwarding engine to meet user requests.Cache is the cornerstone of ICN network architecture and a hotspot of ICN network research, and its characteristics of transparency, ubiquity and fine granularity make it one of the main methods to solve the explosive traffic growth. However, due to the line-speed requirement, the capacity of cache space is limited. Therefore, it is important to choose the appropriate cache strategy to make reasonable use of the cache and improve data acquisition speed. ICN network commercialization process requires it to adapt to multi-domain environment, and when the ICN is extended to multiple domains, the cache can become the bargaining chip for commercial negotiation by network providers. Therefore, the design goals of multi-domain cache strategies are to meet the inter-domain business relationships, effectively deploy the network caches, set the strategy flexibly and get good user experience, which put forward new challenges to the research of cache strategies. In this paper, the cache mechanism of ICN network is taken as the starting point, and the caching strategies of single domain and multi -domain environment are studied respectively. The main contributions of this paper are as follows:Firstly, based on the analysis and comparison of the existing caching strategies in a single domain, this paper proposes a hybrid caching strategy based on role division between nodes. The ICN nodes in a domain are assigned different roles according to their importance. The core nodes adopt the explicit HASH coordination strategy, and the edge nodes adopt the implicit LCE or LCD coordination strategies. The hybrid cache strategy can get a better user experience and a good network performance at the same time.Secondly, the current researches of ICN caching strategies are mostly focused on a single domain, however commercialization of ICN requires that caching strategies must be applied to multi-domain and meet the business relationships among network participants. This paper proposes a complete set of ICN caching strategies for inter-domain business relationships, which includes relationship-based strategy, provider-based strategy and a hybrid strategy, namely-relvider. Each domain can select an appropriate caching strategy according to its own needs. Meanwhile, each caching strategy is divided into inter-domain caching decision, intra-domain caching decision,and intra-domain cache replacement. The corresponding request forwarding strategies and content advertisement strategies are also proposed. By the way, the proposed methods satisfy the business relationships and user demands, and achieve a reasonable use of the cache and better network performance.Thirdly, this paper extends and improves the CCN network, a representative of ICN network architecture. It also extends the simulation framework—ccnSim to implement the hybrid caching strategy based on the node's role division and inter-domain caching strategies which conform to commercial relationships. This paper compares these strategies with other strategies through simulation experiments to verify the effectiveness and performance. |
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