this paper, we will assume that all window sizes are measured in units of maximum size packets, instead of bytes. In the original TCP specification [10], the window used by the sender, which we will denote by wnd, is the 1

We present an artificial workload model of wide-area internetwork traffic. The model can be used to drive simulation experiments of communication protocols and flow and congestion control experiments. The model is based on analysis of wide-area TCP/IP traffic collected from one industrial and two academic networks. The artificial workload model uses both detailed knowledge and measured characteristics of the user application programs responsible for the traffic. Observations drawn from our measurements contradict some commonly held beliefs regarding wide-area TCP/IP network traffic.

This document is an Internet-Draft and is in full conformance with all provisions of Section 10 of RFC2026. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet-Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress". The list of current Internet-Drafts can be accessed at

This memorandum is a companion document to the current version of the RTP protocol specification draft-ietf-avt-rtp-*.ftxt,psg. It discusses protocol aspects of transporting real-time services (for example, voice or video) over packet-switched networks such as the Internet. It compares and evaluates design alternatives for a real-time transport protocol, providing rationales for the design decisions made for RTP. Also covered are issues of port assignment and multicast address allocation. An appendix provides a comprehensive glossary of terms related to multimedia conferencing. This document is a product of the Audio-Video Transport working group within the Internet Engineering Task Force. Comments are solicited and should be addressed to the working group's mailing list at rem-conf@es.net and/or the author(s). INTERNET-DRAFT draft-ietf-avt-issues-02.ps May 9, 1994 Contents 1 Introduction 4 2 Goals 7 3 Services 9 3.1 Control and Data : : : : : : : : : : : : : : : : : : : : : : : : ...

Work on network-attached peripherals (NAPs) can be divided into essentially three areas -- device interfaces and protocols, multimedia use and mass storage use. This paper is an extended abstract reviewing some of the current work and provides references and WWW pointers to many of the projects. The impact of this technological advance on operating systems is discussed. The primary purpose of this paper is to broaden understanding of the advantages and pitfalls of NAPs and encourage further research in the design and use of network-attached peripherals and NAP-capable systems. This paper 1 and an extended abstract are available on the web or from the author. 2 Note: This is a preliminary version of inprogress, unreviewed and incomplete work. Data, conclusions and verbiage may all change. Not yet for public distribution. 1

Congestion control for best effort service in the Internet and other packet-switched networks (e.g., ATM) has been intensely studied in recent years. Many different congestion control mechanisms have been proposed and analyzed. In this paper we step back from the details of the various proposals and ask a more fundamental question: what principles should guide the design and implementation of best effort service in future packet-switched commercial networks? We ask this question because the current paradigm in congestion control, which is to trust end users to follow mandated congestion control algorithms, may no longer be viable in future public networks. Instead, we believe that the fundamental paradigm for best effort congestion control should be based on two principles. The first principle is that the network should enable users to achieve good service. This requires that the network provide adequate feedback so that end users can use the available bandwidth effectively. The second...

Introduction The real-time transport protocol (RTP) discussed in this note aims to provide provide services commonly required by interactive multimedia conferences, in particular playout synchronization, demultiplexing, media identification and active-party identification. In this context and for a lack of a better concise term, a conference is meant as a catch-all terms to describe associations that are characterized by the participation of two or more agents, interacting in real time with one or more media of potentially different types. The agents are anticipated to be human, but may as well be measurement devices, remote media servers, simulators and the like. Both two-party and multiple-party associations are to be supported, where one or more agents can take active roles, i.e., generate data. Thus, applications not commonly considered a conference fall under our wider definition, for example, one-way media such as the network equivalent of closedcircuit t

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Simulation is the main tool for studying networking protocols before deploying them in a wide scale, or for understanding how they are expected to behave under various conditions. IRLSim is a new packet level network simulator that we developed in the hope to study several Internet protocols. From its modest inception as a simulator for the RSVP signaling protocol, IRLSim has evolved into a more general purpose, easy to use, scalable simulator that can be used as a guide for studying existing network protocols as well as a research tool for developing new protocols. This paper describes the architecture of IRLSim in detail, presents its use in the study of a few specific networking problems and argues about its usefulness amongst the variety of other simulators.