Jointly Optimal Routing and Caching for Arbitrary Network Topologies

• Published in: IEEE journal on selected areas in communications Vol. 36; no. 6; pp. 1258 - 1275
• Main Authors: Ioannidis, Stratis, Yeh, Edmund
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.06.2018; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Adaptive algorithms; Algorithms; Approximation; Approximation algorithms; Caching; Computer simulation; convex relaxation; distributed optimization; forwarding; Mathematical analysis; Network topologies; Network topology; Optimization; Peer-to-peer computing; pipage rounding; Routing; Routing protocols; Servers; Topology
• ISSN: 0733-8716; 1558-0008
• DOI: 10.1109/JSAC.2018.2844981

We study a problem of minimizing routing costs by jointly optimizing caching and routing decisions over an arbitrary network topology. We cast this as an equivalent caching gain maximization problem, and consider both source routing and hop-by-hop routing settings. The respective offline problems are NP-hard. Nevertheless, we show that there exist polynomial time approximation algorithms producing solutions within a constant approximation from the optimal. We also produce distributed, adaptive algorithms with the same approximation guarantees. We simulate our adaptive algorithms over a broad array of different topologies. Our algorithms reduce routing costs by several orders of magnitude compared with prior art, including algorithms optimizing caching under fixed routing.