Browsing by Subject "Multicasting (Computer networks)"
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Item Cooperative resource discovery and sharing in group communications(2003) Lee, Jangwon; De Veciana, GustavoItem Design of a P2P-based network architecture for automated test equipment(Texas Tech University, 2004-05) Pandit, ParagSchemes that use intercormected devices such as control systems and Automated Test Equipment (ATE) traditionally use software that is built upon the client-server model. As a result, these systems are incapable of guaranteeing control of the master over slaves in the event of many cases of system failure. Also, these systems are often written in compiled languages like 'C' or 'Assembly', which makes the task of recompiling software and rebooting systems necessary when modifications are performed. In an effort to provide greater fault tolerance and reliability, we explore the possibility of using the P2P model for networking devices. Moreover, we attempt to use scripts for defíning system behavior, which provides flexibility and ease in making modifications at runtime. We met our goal by developing a distributed P2P architecture for confederations of devices and by defíning an XML-based scripting language for writing distributed applications that run on the said platform. Message protocols for communication between devices were defíned. Many useful features were implemented that make the framework powerfiil and yet simple to use.Item Robust congestion control for IP multicast(2003) Gorinsky, Sergey; Vin, Harrick M.IP multicast is a network service for scalable distribution of data to multiple receivers. Traditional protocols for multicast congestion control rely on trust: each party is assumed to follow guidelines for fair bandwidth sharing. However, with the growth and commercialization of the Internet, the assumption of universal trust is no longer tenable. In this dissertation, we consider a relaxed model where receivers are untrustworthy and can misbehave to acquire an unfairly high bandwidth at the expense of competing traffic. Our experiments with existing multicast protocols show that each of the evaluated protocols is vulnerable to receiver misbehavior. To take the first step towards robust multicast designs for distrusted environments, we focus on the class of feedback-free protocols where receivers provide no feedback to the sender and control congestion by regulating their subscription levels in the multi-group session. Unfortunately, the mechanism of group subscription offers a misbehaving receiver an opportunity to inflate its subscription level. Such inflated subscription attacks pose a major threat to fairness of bandwidth allocation. This dissertation is the first to solve the problem of inflated subscription. The presented designs rely on an insight that the ability of a receiver to access a multicast group should be tied with the congestion status of the receiver. First, we address individual attacks where a receiver inflates its subscription with no assistance from other receivers. Our solution guards access to multicast groups with dynamic keys and consists of two independent components: DELTA (Distribution of ELigibility To Access) – a novel method for in-band distribution of group keys to receivers that are eligible to access the groups according to the congestion control protocol, and SIGMA (Secure Internet Group Management Architecture) – a generic architecture for key-based group access at edge routers. DELTA and SIGMA require only minimal generic changes in the edge routers, do not alter the core of the network, and introduce no auxiliary servers. Then, we extend the design to protect multicast congestion control against inflated subscription of colluding receivers. To illustrate that integration with DELTA and SIGMA makes multicast protocols robust to inflated subscription and preserves other congestion control properties, we derive and evaluate robust adaptations of RLM and FLID-DL protocols.