Software Product Description ___________________________________________________________________ PRODUCT NAME:  DECnet/OSI Version 6.1 for OpenVMS AXP  SPD 50.45.05 1  DESCRIPTION DECnet/OSI V6.1 for OpenVMS AXP is an implementation of Phase V of the Digital Network Architecture (DNA) for the OpenVMS Operating System for AXP hardware. DECnet/OSI integrates DECnet and OSI network pro- tocols allowing both stacks to share integrated network functions up to the Transport Layer. Upper Layers have been implemented as sepa- rate "towers" allowing existing DECnet and OSI applications to share the integrated Transport Layer. Existing DECnet Phase IV and new DEC- net and OSI applications are supported by DECnet/OSI. In combination with TCP/IP protocol stacks, OpenVMS systems can participate in mul- tivendor, multiprotocol networks adhering to Open Networking standards. New features for V6.1 include: o  The ability to run DECnet and OSI applications over TCP/IP trans-    ports o  Expanded naming options, allowing the use of a new and larger lo-    cal namespace, DECdns, and/or DNS/bind as naming services o  The Graphical Network Management User Interface for improved net-    work management. Other DECnet/OSI for OpenVMS features include: o  Routing Segregated mode to allow the routing layer to choose a Phase    IV router for those packets having a Phase IV compatible address.    (Packets having a Phase V extended address will be sent to a Phase    V router by default.) This is a configurable option. o  Reverse Path Caching to capture path information for later use in    reaching remote systems. o  Increased network size, supported through the use of ISO OSI ad-    dressing. o  Simplified Installation and Configuration process o  The Network Control Language (NCL). Network management is based on    DNA CMIP, Digital's implementation of the OSI international stan-    dard Common Management Information Protocol. o  An NCP Emulator to facilitate installation of Layered Products writ-    ten for DECnet Phase IV. o  Installation using the POLYCENTER Software Installation utility.                               DIGITAL                 February 1995                                                         AE-Q198F-TE  o  Network naming, allowing the use of either Local Naming or fully    distributed name services. Note that the use of DECdns requires the    presence of an OpenVMS VAX or ULTRIX MIPS system to host the DECdns    Server. The Server is not supported on AXP systems. o  Support for topologies using multicircuit and multihomed end nodes o  Dynamic connections over X.25 networks. o  OSI implementation in accordance with US and UK GOSIPs    -  Application, Presentation, and Session Layers       .  File Transfer Access and Management (FTAM) application       .  Virtual Terminal application       .  ASEs, including ACSE (Association Control Service Element)    -  Transport Layer, Classes 0, 2, and 4    -  Lower Layers       .  OSI Addressing formats, supporting very large network topolo-          gies       .  End System to Intermediate System (ES-IS) routing       .  Connectionless mode Network Service (CLNS) over local area          network (LAN), wide area network (WAN), and X.25       .  LLC2 for CONS over LAN       .  Data Link Layer, supporting HDLC for wide area communications,          ISO 8802-3 (Ethernet CSMA/CD) and FDDI LANs, and DDCMP for          backwards compatibility. HDLC support includes the LAPB pro-          tocol for X.25 communications.       .  Physical Layer, with CSMA/CD, HDLC, and FDDI devices supported. DECnet/OSI for OpenVMS is available in two forms: End System and Ex- tended Function. Extended Function provides all the features of End System plus the OSI Application Gateways (FTAM - DAP gateway, VT-Telnet, VT-LAT) and Cluster Alias. See the SOFTWARE LICENSING section for more details. DECnet/OSI for OpenVMS offers task-to-task communications, file man- agement, downline system and task loading, network command terminals, and network resource sharing capabilities using DNA, ISO and TCP/IP protocols. DECnet/OSI for OpenVMS communicates with adjacent and non- adjacent DECnet Phase IV, PATHWORKS, DECnet/OSI implementations on other OpenVMS, ULTRIX, and DEC OSF/1[R] systems, as well as OpenVMS systems running TCP/IP transports. OpenVMS programs written in native mode programming languages can use DECnet/OSI for OpenVMS capabilities.                                  2  Depending on the system configuration, networks combining DECnet/OSI for OpenVMS systems with other DECnet, OSI and TCP/IP products may limit the functions available if all products do not support equal features. 1.1  Data Link Layer DECnet/OSI for OpenVMS uses synchronous, Ethernet, and FDDI communi- cations controllers to interface with other network nodes. LAN connectivity is provided by the CSMA/CD and FDDI controllers and drivers supporting ISO 8802-2 Logical Link Control (LLC) type 1 con- nectionless service. DECnet/OSI also supports Ethernet V2 packets on CSMA/CD devices. Use of FDDI packets larger than 1500 bytes requires a Phase V router on the FDDI LAN. As with Cluster Alias support, the Phase V router may be configured to run the Phase IV distance vector routing protocol or the Phase V link state routing protocol. WAN connectivity is provided by WAN Device Drivers supporting host- based synchronous communications options for wide area networking. All the data link devices support HDLC/LAPB and SDLC protocols. WAN Device Drivers are required by X.25 to establish host-based wide area connections. DECnet/OSI for OpenVMS allows up to four circuits to be defined and operational on an End System. This capability allows a single end sys- tem to be connected to up to four separate LANs or WANs. Note that all circuits must be equal in capacity and connectivity. 1.2  X.25 The X.25 software allows DECnet/OSI for OpenVMS AXP systems to con- nect to PSDNs conforming to CCITT Recommendation X.25 (1980, or 1984) and/or ISO 7776 and 8208, and to support CONS over Local Area Networks using LLC2 as the Datalink protocol for X.25. It allows process-to- process as well as terminal-to-process communications between AXP sys- tems and a remote DTE over a PSDN. Use of the X.25 software to provide direct access to a PSDN (using the supported WAN device drivers) requires a X.25 license. See the OPTIONAL SOFTWARE section. For more details on the X.25 software for OpenVMS AXP systems, refer to the X.25 V1.0 for OpenVMS AXP Software Product Description (SPD 47.37.xx). 1.3  Network Layer DECnet/OSI for OpenVMS supports both the Connectionless mode Network Service (CLNS) and the Connection mode Network Service (CONS). DEC- net/OSI supports end system routing only.                                  3  Exchange of routing information between end systems and routers uses the ISO 9542 ES-IS routing protocol. This allows DECnet/OSI systems to autoconfigure as end systems with supported others supporting ISO 9542. Addresses conform to the ISO 8348 Addendum 2 specification allowing the support of large network topologies. As long as the system address stays within the addressing range of Phase IV systems (up to 1,023 sys- tems per area and up to 63 areas per network), and uses the same Ini- tial Domain Part (IDP), Phase IV or Phase V routers may be used. The network layer supports the capability of an end system to be mul- ticircuited and multihomed. Multicircuit support allows multiple cir- cuits to be active simultaneously. This increases network reliabil- ity and data throughput. Multihomed end system support allows a sys- tem to have up to three Network Entity Titles. Segregated Routing Mode is a settable attribute. It will direct rout- ing to choose a Phase IV router for those packets having a destina- tion address that can be translated to the Phase IV format. All other packets will be sent to a Phase V router, if available. The routing layer is able to cache information about the paths that are used to reach remote nodes. 1.4  Transport Layer DECnet/OSI for OpenVMS provides support for: o  OSI Transport protocol as specified in ISO 8073 o  RFC 1006 and 1006 Extensions (Internet Draft) to allow DECnet and    OSI applications to run over TCP/IP o  Network Services Protocol (NSP) NSP, RFC 1006 and OSI transports support communications between DEC- net, TCP/IP and OSI systems. NSP provides backwards compatibility with Phase IV DECnet systems. RFC 1006 support for DECnet applications is provided via a kernel in- terface that has been implemented on all TCP/IP stacks available for use on OpenVMS. The supported applications include all licensed DEC- net applications as well as layered products, and user-written appli- cations that conform to the documented DECnet programming interfaces. Internet RFC1006 defines a specification for running OSI applications over TCP/IP. Operation of the FTAM and Virtual Terminal applications over a TCP/IP network is supported along with other layered OSI ap- plications such as X.400 and X.500. A separate TCP/IP stack is required on the same system with DECnet/OSI. See the OPTIONAL SOFTWARE section of this SPD for information on sup- ported TCP/IP products. OSI Transport supports Transport Classes 0, 2, and 4 on Connection Ori- ented networks and Class 4 on Connectionless networks.                                  4  OSI Transport uses two types of network service: o  The Connectionless-mode Network Service (CLNS) using the Internet    protocol (ISO 8473) and ES-IS protocol (ISO 9542) to communicate    across linked subnetworks. The inactive subset of ISO 8473 (null    internet) is also supported for communications over a single ISO    8802-3 local area network. o  The Connection Oriented Network Service (CONS). 1.5  Upper Layers DECnet/OSI for OpenVMS software provides the OSI upper layer stack con- sisting of Session, Presentation and Application layers. The Appli- cation layer provides Association Control Service Element (ACSE), File Transfer, Management and Access (FTAM), and Virtual Terminal (VT). DECnet/OSI for OpenVMS also provides a range of DECnet applications and services including file and record access, remote terminal access, mail, and phone. 1.6  Applications Transport O