Recent work on Information Centric Networking enables the exploitation of the caching resources of the new generation of routers [Content Routers (CR)]. So far, only a basic Least Recently Used strategy implemented on every CR has been proposed. In this paper, we introduce a cooperative caching strategy in the context of a Content-Centric-Network (CCN). This strategy has been designed for the treatment of large video streams with on-demand access. This caching strategy combines the traditional hash-based and directory-based cooperative caching scheme, and addresses the need of the Internet Service Provider by halving the cross-domain traffic. We present a first algorithm, which is a core element of this strategy, then we show the changes that must be brought to the CCN protocol in order to implement this strategy. Thereafter, we prove the advantages of this cooperative policy over standard non-cooperative policies in simple network structures. Finally, we describe an augmented version of the CCNx protocol implementing this policy, and we present a set of simulations that have been conducted on an experimental platform for CCNx.