When AIMD meets ICN: a bandwidth sharing perspective

International audienceInformation-centric networking (ICN) leverages content demand redundancy and proposes in-network caching to reduce network and servers load and to improve quality of experience. In this paper, we study the interaction between in-network caching of ICN and Additive Increase Multiplicative Decrease (AIMD) end-to-end congestion control with a focus on how bandwidth is shared, as a function of content popularity and caches provisioning. As caching shortens AIMD feedback loop, the download rate of AIMD is impacted. Supported by an analytic model based on Discriminatory Processor Sharing and real experiments, we observe that popular contents benefit from caching and realize shorter download times at the expense of unpopular contents which see their download times inflated by a factor bounded by 1/(1− rho) , where rho is the network load. This bias can be removed by redefining congestion control to be delay independent or by over-provisioning link capacity at the edge so that to compensate for the greediness of popular contents