  Internet usage has shifted from host-centric end-to-end communication to a
content-centric approach mainly used for content delivery. Information Centric
Networking (ICN) was proposed as a promising novel content delivery
architecture. ICN includes in-network caching features at every node which has
a major impact on content retrieval. For instance, the ICN efficiency depends
drastically on the management of the caching resources. The management of
caching resources is achieved with caching strategies. Caching strategies
decide what, where and when content is stored in the network. In this paper, we
revisit the recent technical contributions on caching strategies, we compare
them and discuss opportunities and challenges for improving content delivery in
the upcoming years.

Networking and Internet Architecture