Topics: Content delivery networks; Cloud storage
 
 
	Authors: Andrea Araldo (Université Paris Sud & Telecom Paris Tech, France); Gyorgy Dan (KTH Royal Institute of Technology, Sweden); Dario Rossi (Telecom ParisTech, France)
Presenter Bio: Andrea Araldo is a PhD student at Telecom ParisTech and 
Universite' ParisSud, expecting to defend on September 2016. 
He received a MSc in Computer Engineering from Universita' di Catania. 
He has worked for Consorzio Interuniversitario per le Telecomunicazioni 
(CNIT), in the context of the FP7 European Project "Ofelia", 
participating in the implementation of Conet, an Information Centric 
Network (ICN) over Software Defined Networks (SDN). He administrated the
 "island" in Catania connected to the pan-european experimental Ofelia 
network. 
He has focused on Network Measurement in the context of the FP 7 EU 
Project mPlane, analyzing in particular the problem of Bufferbloat. 
During his PhD he visited KTH Royal Institute of Technology (Stockholm) 
working on caching mechanisms for encrypted content. 
He has been teaching assistant in Telecom ParisTech.
 
 
	Abstract:
		In-network caching is an appealing solution 
to cope with the increasing bandwidth demand of video, audio and data 
transfer over the Internet. Nonetheless, an increasing share of content 
delivery services adopt encryption through HTTPS, which is not 
compatible with traditional ISP-managed approaches like transparent and 
proxy caching. This raises the need for solutions involving both 
Internet Service Providers (ISP) and Content Providers (CP): by design, 
the solution should preserve business-critical CP information (e.g., 
content popularity, user preferences) on the one hand, while allowing 
for a deeper integration of caches in the ISP architecture (e.g., in 5G 
femto-cells) on the other hand. 
In this paper we address this issue by considering a content-oblivious 
ISP-operated cache. The ISP allocates the cache storage to various 
content providers so as to maximize the bandwidth savings provided by 
the cache: the main novelty lies in the fact that, to protect 
business-critical information, ISPs only need to measure the aggregated 
miss rates of the individual CPs. We propose a cache allocation 
algorithm based on a perturbed stochastic subgradient method, and prove 
that the algorithm converges to the allocation that maximizes the 
overall cache hit rate. We use extensive simulations to validate the 
algorithm and to assess its convergence rate under stationary and 
non-stationary content popularities. Our results (i) testify the 
feasibility of content-oblivious caches and (ii) show that the proposed 
algorithm can achieve within 15% from the global optimum in our 
evaluation.