Architectural principles support the continuous multimedia applications

In this paper we discuss some of the architectural principles which are useful to support the continuous media applications in a microkernel environment. In particular, we discuss i) the principle of upcall-driven application structuring whereby communications events are system rather than application initiated, ii) the principle of split-level system structuring whereby, key system .functions are carried out co-operatively between kernel and user level components and iii) the principle of decoupling of control transfer and data transfer. Under these general headings a number of particular mechanisms and techniques are discussed

Network Access in a Diversified Internet

There is a growing interest in virtualized network infrastructures as a means to enable experimental evaluation of new network architectures on a realistic scale. The National Science Foundation\u27s GENI initiative seeks to develop a national experimental facility that would include virtualized network platforms that can support many concurrent experimental networks. Some researchers seek to make virtualization a central architectural component of a future Internet, so that new network architectures can be introduced at any time, without the barriers to entry that currently make this difficult. This paper focuses on how to extend the concept of virtualized networking through LAN-based access networks to the end systems. Our objective is to allow virtual networks that support new network services to make those services directly available to applications, rather than force applications to access them indirectly through existing network protocols. We demonstrate that this approach can improve performance by an order of magnitude over other approaches and can enable virtual networks that provide end-to-end quality of service

An Evaluation of the Amoeba Group Communication System

The Amoeba group communication system has two unique aspects: (1) it uses a sequencer-based protocol with negative acknowledgements for achieving a total order on all group messages; and (2) users choose the degree of fault tolerance they desire. This paper reports on our design decisions in retrospect, the performance of the Amoeba group system, and our experiences using the system. We conclude that sequencer-based group protocols achieve high performance (comparable to Amoeba's fast remote procedure call implementation), that the scalability of our sequencer-based protocols is limited by message processing time, and that the flexibility and modularity of user-level implementations of protocols is likely to outweigh the potential performance loss

Building an active node on the Internet

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1997.Includes bibliographical references (p. 63-65).by David M. Murphy.M.Eng