A VAX supercomputer gateway provides a similar interconnection to Cray supercomputers, which are often linked to DECnet engineering LANs for running structural analyses, simulations, and other CPU-intensive programs.
DEC's DECnet-Ultrix communications software permits DEC computers running the VMS and Ultrix operating systems to communicate in Ethernet LANs and DECnet WANs.
Like DECnet, the layered functions defined by TCP/IP approximate, but are not identical to, ISO/OSI model functions, the upper layers of which have not yet been fully defined.
As shown at the center in Figure 1, DECnet software provides the basic networking functions in layers 3, 4, and 5, while the application programs running in the network include the functions in layers 6 and 7.
DEC workstations and high-end computers equipped with DECnet-Ultrix software can communicate in an Ethernet LAN with any computers using either the DECnet or TCP/IP protocols above the two lowest layers.
As was the case within stress analysis's group LAN, message packets based on the DECnet and TCP/IP upper-layer protocols now coexist throughout the extended LAN.
Phase IV DECnet has all the features of Phase III, but expands the maximum number of supported nodes from 255 to 1000.
Last October, Digital announced software products running on the full range of VAX computer systems that provide more extensive links between DECnet and SNA networks.
It enables users on a DECnet network to access both final form document distribution and library services of an IBM System 370 host computer supported by DISOSS/370.
Users of non-Digital computers and terminals will soon be able to communicate with Digital host computers within DECnet environments, thanks to a product developed by Stuart Wecker and his colleagues at Technology Concepts.
Portable DECnet has already been ported to two operating systems: VRTX, a small, real-time operating system that runs on 8086 and 68000-based processors, designed and marketed by Hunter and Ready of Palo Alto, California; and PSOS, a 68000-based, real-time operating system designed and marketed by Software Component Group of Santa Clara, California, for multi-tasking applications.