Performance Evaluation of Load-Balanced Routing via Bounded Randomization

Future computer networks are expected to carry bursty traffic. Shortest-path routing protocols such as OSPF and RIP have t he disadvantage of causing bottlenecks due to their inherent single-path routing. That is, the uniformly selected shortest path between a source and a destination may become highly congested even when many other paths have low utilization. We propose a family of routing schemes that distribute data traffic over the whole network via bounded randomization; in this way, they remove bottlenecks and consequently improve network performance. For each data message to be sent from a source s to a destination d, each of the proposed routing protocols randomly choose an intermediate node e from a selected set of network nodes, and routes the data message along a shortest path from s to e. Then, it routes the data message via a shortest path from e to d. Intuitively, we would expect that this increase the effective bandwidth between each source-destination pair. Our simulation results indicate that the family of proposed load-balanced routing protocols distribute traffic evenly over the whole network and, in consequence, increases network performance with respect to throughput, message loss, message delay and link utilization. Moreover, implementing our scheme requires only a simple extension to any shortest-path routing protocol

Go-With-The-Winner: Client-Side Server Selection for Content Delivery

Content delivery networks deliver much of the web and video content in the world by deploying a large distributed network of servers. We model and analyze a simple paradigm for client-side server selection that is commonly used in practice where each user independently measures the performance of a set of candidate servers and selects the one that performs the best. For web (resp., video) delivery, we propose and analyze a simple algorithm where each user randomly chooses two or more candidate servers and selects the server that provided the best hit rate (resp., bit rate). We prove that the algorithm converges quickly to an optimal state where all users receive the best hit rate (resp., bit rate), with high probability. We also show that if each user chose just one random server instead of two, some users receive a hit rate (resp., bit rate) that tends to zero. We simulate our algorithm and evaluate its performance with varying choices of parameters, system load, and content popularity.Comment: 15 pages, 9 figures, published in IFIP Networking 201

Randomized Protocols for Low-Congestion Circuit Routing in Multistage Interconnection Networks

In this paper we study randomized algorithms for circuit switching on multistage networks related to the butterfly. We devise algorithms that route messages by constructing circuits (or paths) for the messages with small congestion, dilation, and setup time. Our algorithms are based on the idea of having each message choose a route from two possibilities, a technique that has previously proven successful in simpler load balancing settings. As an application of our techniques, we propose a novel design for a data server

Abstract Randomized Protocols for Low-Congestion Circuit Routing in Multistage Interconnection Networks

In tbis paper we study randomized algorithms for circuit switching on multistage networks related to the butterfly. We devise algorithms that route messages by constructing circuits (or paths) for the messages with small congestion, dilation, and setup time. Our algorithms are based on the idea of having each message choose a route from two possibilities, a technique that has previously proven successful in simpler load balancing settings. As an application of our techniques, we propose a novel design for a data server.