Caching over-the-top services, the Netflix case

Over-the-top (OTT) traffic represents around 67% of the downstream Internet data volume during peak periods in the US. OTT content providers have been following the strategy of deploying caching servers within the ISPs´ own networks. This work presents a method for deciding where these caches for OTT services can be conveniently deployed to provide significant traffic offload to ISPs´ back-haul links. The procedure followed is to find suitable caching locations that minimize the maximum link traffic load. The problem is defined and solved as a Link Load Balanced Capacitated Facility Location Problem (LLB-CFL). The solution search processes are implemented based on Genetic Algorithms (GA), designing genetic operators highly targeted towards this specific problem. The proposed methods are applied to a case study focusing on the demand and cache specifications of Netflix, and framed into a real geographical area, the island of Bornholm, Denmark. The results cover a thorough analysis of the cost-fitness trade-off of the search method and an evaluation of both cache and gateway traffic flowing in the network in relation to the solutions found using different network topologies.