The ability to create views of a network on a fast time scale becomes increasingly important as the complexity and diversity of networks increase. These views, which combine information from many distributed points in the network, can provide an administrator with a better understanding of the interdependencies and interactions between network elements and traffic conditions. Applications that could benefit from being able to compute such "near" real-time views of the network range from performance monitoring to fault management. In this paper, we present the architecture of a distributed management infrastructure that enables such views to be computed. Based on our earlier work on decentralized management, our architecture takes a novel database approach that combines the expressive power of SQL with distributed algorithms. We describe the implementation of the system on platform of embedded Linux devices attached to a network of routers. We provide specific examples of how the system can be used as a powerful distributed real-time monitoring platform. Finally, we derive a performance model of the system and validate it with a set of experiments.

Performing global management operations on the Internet in an efficient way is difficult, because of the continuous changes to the Internet topology, its large number of nodes and the lack of an up-to-date global database. In practice, these difficulties appear in the management of large private IP networks and large autonomous systems, which form the sub-topologies of the Internet and are under independent administration. This paper introduces the echo pattern, a scheme for distributing management operations, which addresses these difficulties. Management operations based on this pattern do not need knowledge of the network topology, they can dynamically adapt to changes in the topology, and they scale well in very large networks. A management operation based on the echo pattern has two phases. In a first phase, the network is being flooded with management commands to be run on the network elements. In the second phase, the results of the local management operations are aggregated inside the network. We analyze the echo pattern with respect to time and traffic complexity and compare its performance to that of a centralized management scheme. Our results show that "typical" echo-based management operations could be executed within some 18 seconds on the entire Internet. This short time is due to (1) the high degree of parallelism and distributed control in this pattern and (2) some specific properties of the Internet topology.

The Binding Architecture is an open architecture for building multimedia networks that must guarantee quality of service (QOS). We explore the notion of a service in the Binding Architecture and propose a conceptual model for building scalable multimedia distribution services based on it. We begin first by examining the relation between resources, their abstractions and the services that can be built from them and use this to derive a general model for binding. Based on this model, we identify a general set of capabilities required for building any multimedia distribution service. We also describe how these capabilities can be incorporated into our view of the service creation process. Finally, we augment our discussion with the description of an example service which we have developed using this paradigm.

A conceptual framework, called the binding model, for the creation, deployment and management of multimedia services on ATM-based broadband networks with end-to-end quality-of-service (QoS) guarantees is presented. The key function of the associated binding architecture is to provide an open programmable environment that facilitates the easy creation of flexible services. We describe the implementation of a prototype binding architecture called xbind as a middleware toolkit for building open programmable ATM networks. Finally, we present our initial experiences with experimenting and deploying xbind over an ATM testbed and highlight some of the lessons learned.

An open architecture that achieves seamless binding between networking and multimedia devices is proposed. The building blocks of the binding architecture consist of a set of interfaces, methods and primitives. The former abstract the functionalities of multimedia networking devices and are realized as objects organized into a binding interface base. The methods and primitives are invoked for implementing binding applications. The binding architecture is embedded into a reference model for multimedia networking architectures that supports a clean separation between binding interfaces and binding algorithms. Communication between the objects realizing the binding interfaces is supported by CORBA. Public interfaces in the binding interface base are specified using CORBA IDL. The architecture is illustrated with a simple connection management algorithm and an example of computational binding.

The Fiber Distributed Data Interface (FDDI) is an ANSI standard for high speed fiber optic ring networks. Its media access control (MAC) protocol operates on the basis of a timed-token ring, and allows the transmission of both time critical and normal prioritized data. Because of these characteristics, it is highly suitable for use in a multimedia environment where there are a mixture of synchronous and asynchronous data classes. This paper describes an implementation of the FDDI MAC protocol using the RESQ2 simulation language and studies the behaviour of the protocol when used as a large multimedia backbone network where stations represent gateway connections to peripheral LANs. It also investigates the behaviour of symmetric and asymmetric loading on such large networks and some potential problems that may be encountered.

A scalable and reusable emulator was designed and implemented for studying the behavior of SS7 networks. The emulator design was largely based on public domain software. It was developed on top of an environment supported by PVM, the Parallel Virtual Machine, and managed by OSIMIS/spl minus/the OSI Management Information Service platform. The emulator runs on top of a commercially available ATM LAN interconnecting engineering workstations. As a case study for evaluating the emulator, the behavior of the Singapore National SS7 Network under fault and unbalanced loading conditions was investigated.>