NCAF: a reduced flooding mechanism for route discovery in ICN

Information Centric Network or ICN is one of the few popular designs envisioned for the future Internet. In ICN, packets are routed by content-object names. Such names can be much more complicated as well as order of magnitude more in quantity than IP addresses, and the same content-objects might also be available for retrieval at more places in the network. As routing tables are always limited in space, it is very unlikely that they can hold the routing information for all these names at all times, therefore some kind of on-demand route discovery mechanism is always a necessity for ICN. Flooding is a safe method for such purpose that can assure route optimality, but it is very heavy in terms of incurred messaging traffic. On the other hand, large content-objects are better retrieved and routed in chunks instead of as a complete whole for better networking efficiency, therefore a miss in the routing table might result in a series of flooding for all the chunks of the target content. In this study we call chunks of the same content as neighboring chunks, and propose a route discovery mechanism that makes use of their relationship to reduce the overhead of successive flooding: when one chunk is requested across the network, its neighboring chunks are also reported back just in case. Compared with previous work, our algorithms can achieve faster route discovery without much loss to the routing quality, which makes them suitable for different needs to the route discovery in ICN.