Static routing

About: Static routing is a research topic. Over the lifetime, 25733 publications have been published within this topic receiving 576732 citations.

A predictive access-controll and routing system for integrated services telecommunication networks

Abstract: A predictive access-control and routing system for a telecommunications network operating in uncertain environments and capble of handling heterogeneous traffic. The system is a real-time, state-dependent network traffic control system in which the control strategy is a function of both real-time congestion levels and real-time traffic profiles. At specific time epochs, the system, using real-time measurements of source-destination arrival dates and trunk group link occupancies, generates predictions of all network trunk group occupancy levels for the next epoch as a function of routing and access control. It then minimizes a projected cost function, such as blocking, to generate a traffic control policy to be implemented during the next time interval.

Large-Scale Content-Based Publish-Subscribe Systems

Abstract: Today, the architecture of distributed computer systems is dominated by client/server platforms relying on synchronous request/reply. This architecture is not well suited to implement information-driven applications like news delivery, stock quoting, air traffic control, and dissemination of auction bids due to the inherent mismatch between the demands of these applications and the characteristics of those platforms. In contrast to that, publish/subscribe directly reflects the intrinsic behavior of information-driven applications because communication here is indirect and initiated by producers of information: Producers publish notifications and these are delivered to subscribed consumers by the help of a notification service that decouples the producers and the consumers. Therefore, publish/subscribe should be the first choice for implementing such applications. The expressiveness of the notification selection mechanism used by the consumers to describe the notifications they are interested in is crucial for the flexibility of a notification service. Content-based notification selection is most expressive because it allows to evaluate filter predicates over the whole content of a notification. The advantage in expressiveness compared to channel- or subject-based selection results in increased flexibility facilitating extensibility and change. On the other hand, scalable implementations of content-based notification services are difficult to realize. Indeed, the expressiveness of notification selection must be carefully chosen in large-scale systems, because expressiveness and scalability are interdependent. Hence, the most fundamental problem in the area of content-based publish/subscribe systems is probably the scalable routing of notifications from their producers to their respective consumers. Unfortunately, existing content-based notification services are not mature enough to be used in large-scale, widely-distributed environments. Most existing notification services are either centralized, use flooding, or use simple routing algorithms that assume that each event broker has global knowledge about all active subscriptions. All these approaches exhibit severe scalability problems in large-scale systems. In contrast to that, this thesis concentrates on mechanisms to improve the scalability of content-based routing algorithms and presents more advanced routing algorithms that do not rely on global knowledge. The algorithms presented here exploit similarities between subscriptions by using identity- and covering-tests, and by merging filters. While identity-based routing is a simplified version of covering-based routing, merging-based routing is more advanced because it exploits the concept of filter merging. Furthermore, the idea of imperfect routing algorithms is introduced. The thesis consists of a theoretical and a practical part. The theoretical part presents a formal specification of publish/subscribe systems, a routing framework and a set of routing algorithms, and discusses how the routing optimizations can be broken down to the actual data/filter model. The practical part presents the implementation of the Rebeca notification service which supports advertisements and all the routing algorithms mentioned above. A detailed practical evaluation of the implemented algorithms based upon the prototype is also presented.

Routing device utilizing an ATM switch as a multi-channel backplane in a communication network

Abstract: A data communications network providing for a multiport router and providing for use of an asynchronous transfer mode (ATM) switch or the like as a routing backplane or packet switching engine. A router front end formats ATM cells including providing routing information in the cell header. The routing information may comprise, for example, a destination port identifier in the VPI field of the cell header. The ATM switch then switches the cell from an input port, coupled with the router front end to an output port based on the routing information. The ATM switch may also translate the routing information to provide source identification information to the destination. In a described embodiment, the multiport router is used as a backplane bus in a network concentrator.