A tracker-based cache utilization strategy in CCN

One important feature of Content-centric Networking (CCN) is to utilize built-in network caches to improve the transmission efficiency of content dissemination. In CCN, all nodes have the function of caching contents. Consequently, caches are ubiquitous and diverse. How to make full use of these caches to reduce the network load and the transmission delay has become a hot research topic in recent years. In order to speed up content distribution and improve network resource utilization, a cooperative caching strategy called Tracker-based Cache Utilization Strategy (TBCUS) is proposed in this paper. In TBCUS, an idea of partial centralized management of the caches is introduced into traditional CCN. Moreover, in order to alleviate the pressure that the incurred overhead imposes on network bandwidth, TBCUS divides the whole caching system into several sub-systems. Each of the sub-systems has a tracker server as the controller and some peers. The contents cached in a sub-system are transparent to each other through the coordination of the tracker server. Once a content request reaches to a sub-system, all the caches in the sub-system can be selected to respond to this request. While the traditional caching strategy in CCN is that only the caches on the delivery path can be used to respond to the content request. TBCUS improves the cache utilization and has higher cache hit ratio and lower transmission delay and network load compared with the traditional caching strategy.