Browse Prior Art Database

DCN local-network protocols (RFC0891)

IP.com Disclosure Number: IPCOM000003940D
Original Publication Date: 1983-Dec-01
Included in the Prior Art Database: 2000-Sep-13
Document File: 25 page(s) / 65K

Publishing Venue

Internet Society Requests For Comment (RFCs)

Related People

D.L. Mills: AUTHOR

Abstract

This document describes the local-net architecture and protocols of the Distributed Computer Network (DCN), a family of local nets based on Internet technology and an implementation of PDP11-based software called the Fuzzball. DCN local nets have been in operation for about three years and now include clones in the USA, UK, Norway and West Germany. They typically include a number of PDP11 or LSI-11 Fuzzballs, one of which is elected a gateway, and often include other Internet-compatible hosts as well.

This text was extracted from a ASCII document.
This is the abbreviated version, containing approximately 4% of the total text.

Network Working Group D.L. Mills

Request for Comments: 891 December 1983

DCN Local-Network Protocols

This RFC is a description of the protocol used in the DCN local

networks to maintain connectivity, routing, and timekeeping

information. These procedures may be of interest to designers and

implementers of other networks.

1. Introduction

This document describes the local-net architecture and protocols

of the Distributed Computer Network (DCN), a family of local nets

based on Internet technology and an implementation of PDP11-based

software called the Fuzzball. DCN local nets have been in operation

for about three years and now include clones in the USA, UK, Norway

and West Germany. They typically include a number of PDP11 or LSI-11

Fuzzballs, one of which is elected a gateway, and often include other

Internet-compatible hosts as well.

The DCN local-net protocols are intended to provide connectivity,

routing and timekeeping functions for a set of randomly connected

personal computers and service hosts. The design philosophy guiding

the Fuzzball implementation is to incorporate complete functionality

in every host, which can serve as a packet switch, gateway and service

host all at the same time. When a set of Fuzzballs are connected

together using a haphazard collection of serial, parallel and

contention-bus interfaces, they organize themselves into a network

with routing based on minimum delay.

The purpose of this document is to describe the local-net

protocols used by the DCN to maintain connectivity, routing and

timekeeping functions. The document is an extensive revision and

expansion of Section 4.2 of [1] and is divided into two parts, the

first of which is an informal description of the architecture,

together with explanatory remarks. The second part consists of a

semi-formal specification of the entities and protocols used to

determine connectivity, establish routing and maintain clock

synchronization and is designed to aid in the implementation of cohort

systems. The link-level coding is described in the appendix.

2. Narrative Description

The DCN architecture is designed for local nets of up to 256

hosts and gateways using the Internet Protocol (IP) and client

protocols. It provides adaptive routing and clock synchronization

functions in an arbitrary topology including point-to-point links and

multipoint bus systems. It is intended for use in connecting personal

computers to each other and to service machines, gateways and other

hosts of the Internet community. However, it is not intended for use

in large, complex networks and ...