Davide Cherubini - PhD Thesis - UniCA Eprints

Chapter 1Introduction1.1 MotivationIn the last few years, the Internet has exponentially expanded to a worldwidenetwork connecting several millions of users.The explosion of peer-to-peer (P2P) file sharing had a significant impact on availablebandwidth of Internet Service Providers (ISP) networks. In fact, P2P applicationsprovides a highly and cheaper accessible way for downloading or sharingmultimedia contents. The resulting bandwidth congestion causes loss of performanceand possible failure situations. Such events might be technically andeconomically harmful.In the last decade, new techniques leading to find a near-optimal traffic routingscenario have been developed. Traffic Engineering (TE) enables ISPs to routenetwork traffic in such a way that they can offer the best service to their users interms of throughput and delay, moving traffic from congested links to less loadedareas of the network (load balancing). Subsequently, the design of survivablemesh based telecommunication networks has received considerable attention inrecent years.Network survivability techniques have been developed to guarantee seamlesscommunication services in the face of network failures. Traditionally, two techniqueshave been proposed to make a network survivable, namely:1. network design and capacity allocation1