DECnet Digital Network Architecture Phase IV Network Management Functional Specification

This document, "DECnet Digital Network Architecture Phase IV: Network Management Functional Specification" (Order No. AA-X437A-TK, December 1983), serves as a comprehensive model for implementing Network Management (NM) software within DECnet.

The core purpose of the document is to describe the functions, structures, protocols, algorithms, and operation of DECnet Network Management modules, providing users and programs with control and observation capabilities over network functions.

Key areas covered include:

1. Functional Description: Explains how Network Management enables operators and programs to control and monitor network operations, aiding in network planning, fault detection, isolation, and resolution. It details control functions (loading remote systems, configuring resources, setting parameters, initiating/terminating functions) and monitoring functions (dumping systems, examining configuration status, parameters, operational status, and performance variables).
2. Network Management Models: Presents two perspectives:
   • User Perspective: A simplified view of the network managed through commands using "verb entity entity-option" syntax (e.g., SET, CLEAR, SHOW, LOAD, LOOP). Entities include Nodes, Areas, Logging, Circuits, Lines, and Modules (e.g., X.25 access/protocol/server, link maintenance). Parameters, counters, and events associated with each entity are extensively detailed.
   • DNA Layer Perspective: Describes how NM components are distributed across the Digital Network Architecture's User, Network Management, and Network Application layers, with the NM layer having direct control over lower layers.
3. Network Control Program (NCP): Specifies the commands and operations of NCP, the primary operator interface for network control and observation. This includes commands for changing parameters, gathering information, performing down-line loads, up-line dumps, triggering bootstraps, testing links and networks, and zeroing counters.
4. Internal Operations: Details the internal workings of Network Management components, such as NICE Access Routines, the Network Management Listener, Local Network Management Functions, Link Watcher, Data Link Service Functions, Event Logger, Loopback Mirror, and mechanisms for handling return codes and version compatibility.
5. Network Management Messages: Defines the Network Information and Control Exchange (NICE) protocol, which underpins inter-node communication for NM. This section specifies message formats, function codes for various NM operations, and data formats for events.
6. Binary Formats and Values: Provides a detailed specification of the binary formats for all network entities, their parameters, counters, and events, along with associated values and display notations.
7. Appendices: Include crucial information on version compatibility between DECnet phases, a definition of the minimum subset of NM functions required for implementations, state mapping tables, X.25 native-only subsets, memory image formats for loading/dumping, NICE return codes, NCP command status/error messages, and algorithms for Julian half-day conversions.

In essence, this document is a foundational technical blueprint for developers implementing DECnet Network Management, covering both the user-facing functionality and the underlying architectural and protocol specifications.