23 - STUDENT - OpenCache: Experimentation on a Grand Scale

Matthew Broadbent (Lancaster University)

Over the last 15 years, the Internet has had to support a significant growth in the distribution of video content. Globally, Internet video traffic was 59% of all consumer Internet traffic in 2012 and is predicted to be 69% in 2017 [1], [2].
Web servers and caches have traditionally been used to store static web content (e.g. HTML pages, images, web documents etc.) in an effort to improve the efficiency of content delivery in a network. However, delivering video poses its own set of unique challenges and constraints, including higher sensitivity to latency and increased throughput requirements.
With a Video-on-Demand (VoD) service, individuals can retrieve content at a time after it was initially broadcast or made available. However, when large amounts of content are delivered through independent unicast flows, current techniques naively ignore that much of the data transferred is
identical to transmissions hours or days earlier. This duplication greatly challenges network provision. Mechanisms are therefore sought to reduce the impact of repeated delivery of identical content over the network, and to reduce the cost of delivery to the network operator.
To address the aforementioned VoD distribution challenge, we have developed OpenCache; an in-network caching platform that leverages Software Defined Networking (SDN) to provide unprecedented levels of control and flexibility.
OpenCaches functionality is based on a number of powerful interfaces that are designed to offer transparent caching with the use of OpenFlow. The core entities of OpenCache, namely the OpenCache Controller and the OpenCache Nodes (see Figure 1), operate in harmony with an OpenFlow Controller to create a content delivery platform that can be deployed into
SDN-enabled networks.
Comparisons between existing Content Distribution Networks (CDNs) and potential OpenCache deployment scenarios are easy to make. Offering similar functionality, we foresee that OpenCache will aid in informing and developing the next-generation of content distribution infrastructure and practises.
As such, large-scale deployments of OpenCache can be used to effectively evaluate new caching techniques, methods and processes. This includes the use of SDN, dynamic and configurable cache instances, and new interfaces for control, maintenance and monitoring.
The OpenCache system is currently being evaluated using the GEANT OpenFlow Facility (GOFF). This activity forms the primary contribution within the Cross-site Evaluation of Fig. 1. OpenCache Architecture
an OpenFlow-assisted Video-on-Demand Distribution Service (CEOVDS) project, an open call participant of GN3plus. With OpenFlow at its core, the facility provides everything necessary to effectively evaluate OpenCache as a prototype. Furthermore, GOFF also acts as a platform to enable the nextgeneration of content distribution experimentation. Without such facilities, work would be confined to simulation and laboratory environments, where realistic conditions, sufficient resources and unforeseen impediments do not exist. This poster will outline the design of OpenCache; highlighting the requirements for high-quality video streaming
and efficient in-network caching that our approach aims to satisfy. It will emphasise the benefits that a Software Defined Networking solution can yield in this problem domain, and highlight the key benefits that OpenCache aims to provide.

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