This paper discusses the use of link-sharing mechanisms in packet networks and presents algorithms for hierarchical link-sharing. Hierarchical link-sharing allows multiple agencies, protocol families, or traflic types to share the bandwidth on a tink in a controlled fashion. Link-sharing and real-time services both require resource management mechanisms at the gateway. Rather than requiring a gateway to implement separate mechanisms for link-sharing and real-time services, the approach in this paper is to view link-sharing and real-time service requirements as simultaneous, and in some respect complementary, constraints at a gateway that can be implemented with a unified set of mechanisms. White it is not possible to completely predict the requirements that might evolve in the Internet over the next decade, we argue that controlled link-sharing is an essential component that can provide gateways with the flexibility to

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Integrated Services Packet Networks (ISPN) are designed to integrate the network service requirements of a wide variety of computer-based applications. Some of these services are delivered primarily through the packet scheduling algorithms used in the network switches. This paper addresses two questions related to these scheduling algorithms. The first question is: what scheduling services should an ISPN offer? In answer, we propose a scheduling service model for ISPN's which is based on our projections about future application and institutional service requirements. Our service model includes both a delay-related component designed to meet the ergonomic requirements of individual applications, and also a hierarchical link-sharing component designed to meet the economic needs of resource sharing between different entities. The second question we address is: what implications does this service model have for the packet scheduling algorithms? We answer this question by construc...

The Internet is currently being confronted with service demands from a new generation of applications. Supporting these applications effectively and efficiently will require extending the current Internet "best-effort" service model to one that offers an integrated suite of services. The purpose of this memo (which is derived primarily from [34]) is to describe a proposed "core" service model for an integrated services Internet. In the Appendix we discuss the process by which such a service model could be standardized by the Internet.

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This paper examines the issues of implementation and integration in multicast. A framework for multicast forwarding is presented, which separates multicast forwarding from any associated protocols that may affect the forwarding decisions, such as multicast routing, resource management and host membership protocols. This framework allows seamless integration of various associated protocols and provides a unified interface for new development.

Traditionally packet switching networks have supported only best-effort traffic. Newer applications need communication services that allow end clients to transport data with performance guarantees given in terms of delay, delay variation, bandwidth, and loss rate. The choice of the packet scheduling algorithm to be used at switching nodes is very crucial to provide the quality of service We have conducted a literature survey covering various scheduling disciplines that can be used to provide performance guarantees to clients. In this thesis, we have compared select scheduling disciplines in an experimental study using simulation. Weighed fair queueing, Class based queueing, and Rate-controlled static priority queueing, are the scheduling disciplines chosen for the study. The traffic types used in the study are CBR, VBR, ABR and UBR flows. For real-time flows used in the experiments, traffic source models for audio and video traffic were used as candidates for CBR and VBR flows. An ext...

With a new United States Army initiative to exploit commercially developed information technology, there is a heightened interest in using Internet protocols over the military’s geosynchronous satellite links. TCP is the dominant Internet protocol used for reliable data exchange, but its own design limits performance when used over long delay network links such as satellites. Initially this research set out to compare TCP with another proposed protocol, the Satellite Transport Protocol (STP). However through a series of tests, we found that STP does not fulfill its claims of increased throughput over TCP and uncovered a flaw in STP’s founding research. In addition, this thesis proposes and demonstrates novel performance enhancing techniques that significantly improve transport protocol throughput. iii Acknowledgements First, I would like to thank my advisor, Prof. David Cyganski, for sharing his insights in physics, electrical engineering, and the art behind successful presentations. Next, I would like to thank my thesis committee, Prof. Brian King and Prof. William Michalson, for their time and helpful suggestions, and I would like to thank Raytheon’s Network Centric Systems Division for sponsoring the research project which provided ample thesis material