http://hdl.handle.net/10016/890 2013-05-18T19:53:00Z http://hdl.handle.net/10016/14525 Title: Seamless integration of unidirectional broadcast links into QoS-constrained broadband wireless mesh access networks Author(s): Kretschmer, Mathias; Ghinea, Gheorgita Abstract: Wireless Mesh Networks (WMNs) have matured in recent years. They allow two nodes to communicate via multiple hops when no direct connectivity exists. This allows community networks such as Freifunk [3] to provide affordable Internet access to their communities by sharing a few gateway nodes. Increasing demand for multi-media content poses a challenge for the typical WMN routing protocols such a Optimised Link State Routing (OLSR) which lack Quality of Service (QoS) support. Although, numerous solutions have been proposed to introduce QoS awareness such as [4], those WMNs fail to meet commercial operator requirements in term of reliability and QoS guarantees. In this paper we propose the seamless integration of Broadcast technologies such as Digital Video Broadcast (DVB) to introduce support for high-bandwidth multi-media services. Description: Proceeding of: International Conference for Internet Technology and Secured Transactions ICITST 2009, London, U.K., 9-12 Nov. 2009 2009-10-31T23:00:00Z http://hdl.handle.net/10016/14391 Title: Understanding incentives for prefix aggregation in BGP Author(s): Kalogiros, Costas; Bagnulo, Marcelo; Kostopoulos, Alexandros Abstract: Over the last few years, a significant amount of the effort of the Future Internet architecture is devoted in order to improve the scalability of the next generation routing architecture. In this paper, we study providers’ incentives to perform prefix aggregation or deaggregation of non-customers routes. This is essentially a tradeoff between reduced router memory and reduced capacity of attracting customer traffic. We study the case where two ISPs compete for attracting traffic, by using game theory. In particular, we propose a game-theoretic model and we analyze the properties of the equilibrium. In a symmetric case, if a single Autonomous System (AS) is found to be deaggregating a given prefix, then all others will have the incentive to do the same, even if they end up with lower benefits. We find that pure equilibria do not always exist and we derive the conditions based on two model parameters. These findings suggest that BGP instability can be a common problem in a competitive scenario. Description: Proceeding of: ReArch'09, Proceedings of the 2009 workshop on Re-architecting the internet, (49-54), 1 December 2009, Rome, Italy. 2009-11-30T23:00:00Z http://hdl.handle.net/10016/14148 Title: OmTCP: increasing performance in server farms. Author(s): Beijnum, Iljitsch van; Azcorra, Arturo; Bagnulo, Marcelo Abstract: Normal TCP/IP operation is for the routing system to select a best path that remains stable for some time, and for TCP to adjust to the properties of this path to optimize throughput. By executing TCP’s congestion control algorithms on multiple paths at the same time, a multipath TCP can shift its traffic to a less congested path, thus maximizing both the throughput for the multipath TCP user and leaving more capacity available for other traffic on more congested paths. And when a path fails, this can be detected and worked around by multipath TCP much more quickly than by waiting for the routing system to repair the failure. This paper proposes a one-ended multipath TCP that is implemented on the sending host only, without requiring modifications on the receiving host, for the purposes of maximizing performance in transmissions from multiply connected large servers towards singly connected end-users and recovering from failures more quickly. Description: Proceedings of: 2010 IEEE International Conference on Communications (ICC 2010), 23-27 May 2010, Cape Town, South Africa 2010-04-30T22:00:00Z http://hdl.handle.net/10016/14118 Title: Opportunistic mobility with multipath TCP Author(s): Raiciu, Costin; Nicolescu, Dragos; Bagnulo, Marcelo; Handley, Mark Abstract: Host mobility has traditionally been solved at the network layer, but even though Mobile IP has been standardised for 15 years, it hasn’t been supported by operators. IP’s double role as a location identif er and communication endpoint identif er brings a number of functional and performance problems. We argue that the best place to handle mobility is at the transport layer. While this is not a new argument, we believe that the emerging standard of Multipath TCP (MPTCP) can be used to solve many issues related to mobility. MPTCP naturally implements make-before-break, can be incrementally deployed, is backwards compatible with standard TCP, and could even ease incremental adoption of IPv6. Using simulations and indoor experiments with WiFi and 3G, we show that MPTCP gives better throughput, achieves smoother handoffs, and can be tuned to lower energy consumption. Description: Proceedings of: ACM MobiArch 2011, The 6th ACM International Workshop on Mobility in the Evolving Internet Architecture, June 28, 2011, Washington, D.C. 2011-06-27T22:00:00Z