DECnet-Plus

This "DECnet-Plus Planning Guide" (November 1996) provides a comprehensive overview of the transition process from DECnet for OpenVMS (Phase IV) to DECnet-Plus for OpenVMS (Phase V) and DECnet/OSI for Digital UNIX.

The primary goal of the transition is to enable networks to support Open Systems Interconnection (OSI) and TCP/IP applications, offering greater scalability, advanced addressing, and enhanced network management capabilities beyond Phase IV limitations.

Key aspects covered in the guide include:

1. Transition Definition and Strategy: Explains the migration of node-name-to-address mapping (from Phase IV local databases to DECdns, DNS/BIND, or Local namespace) and network management (from NCP to NCL). It emphasizes a flexible, multi-step process allowing mixed Phase IV and DECnet-Plus environments.
2. Addressing: Details the new OSI Network Service Access Point (NSAP) address format, which can be Phase IV-compatible or extended. It covers the structure (Initial Domain Part (IDP), Domain-Specific Part (DSP)), how to obtain unique IDPs, and the conversion between Phase IV and NSAP addresses. Features like multihoming and address autoconfiguration are also discussed.
3. Routing: Describes the coexistence of Phase IV routing vector and Phase V link state protocols, including interdomain routing capabilities and the use of interphase links for communication between different routing algorithms.
4. Name Services (DECdns, Local Namespace, and DNS/BIND): Explains how DECnet-Plus uses these services for node-name-to-address translation. It provides extensive guidelines for planning and configuring a distributed DECdns namespace, including directory hierarchies, access control policies, replication strategies, and server placement. The document also introduces the Local namespace as an alternative.
5. Time Services (DECdts): Introduces the Digital Distributed Time Service for synchronizing system clocks across the network, highlighting its benefits (correctness, fault tolerance, automatic configuration, external time-provider support) and planning considerations for various network topologies (LAN, extended LAN, WAN).
6. Network Management and Tools: Details the shift from Network Control Program (NCP) to Network Control Language (NCL) for managing DECnet-Plus nodes. It also introduces various transition tools like decnet_migrate and decnet_register for configuration reporting, database conversion (Phase IV objects, proxy, MOP), and namespace management.
7. Compatibility and Non-Migration: Clarifies backward compatibility with DECnet Phase IV, while noting non-interoperability with Phase II/III and listing specific products and hardware that do not migrate to DECnet-Plus.

The guide is aimed at network planners, managers, and system administrators responsible for planning, implementing, and managing the migration to a DECnet-Plus environment.