DECnet Digital Network Architecture Phase IV Ethernet Node Product Architecture Specification

This document, the "DECnet Digital Network Architecture Phase IV Ethernet Node Product Architecture Specification" (Order No. AA-X440A-TK), published by Digital Equipment Corporation in December 1983, defines the minimum functional requirements for a Digital Equipment Corporation (DEC) node connecting to an Ethernet network within the DECnet Phase IV architecture.

The document's primary purpose is to ensure these nodes are maintainable and provide a foundational base for developing additional product-specific functions. It addresses key functional areas including:

• Initialization and Self-test
• Communication Services
• Communication and System Diagnosis
• Down-line Loading and Up-line Dumping

The specification outlines detailed requirements, design goals (e.g., efficiency, simplicity, network manager control, continued operation during problems), and explicit non-goals to define its scope. It describes the integration of these functions within the Digital Network Architecture (DNA)'s User, Network Management, and Data Link Layers.

A significant aspect is the Ethernet Node Type Model, which classifies nodes based on how they are maintained and controlled (locally or remotely). This model informs the specific functional requirements for different node categories, including:

• All Nodes (general principles, Data Link, Network Management, and User Layer requirements)
• Remote Control Nodes
• Remote Dump/Load Nodes
• Remote Diagnosis Nodes

Finally, the document details the Network Auto-configuration algorithm, explaining how nodes automatically determine network topology and identify themselves through periodic system identification messages, ensuring low overhead and reliability in a dynamic network environment.