==Phrack Inc.== Volume Two, Issue 18, Phile #4 of 11 ------------------------------------------------------------------------- - - - - - PRIMOS: - - NETWORK COMMUNICATIONS - - - - PRIMENET, RJE, DPTX - - - - - - Presented by Magic Hasan June 1988 - ------------------------------------------------------------------------- PRIME's uniform operating system, PRIMOS, supports a wide range of communications products to suit any distributed processing need. The PRIMENET distributed networking facility provides complete local and remote network communication services for all PRIME systems. PRIME's Remote Job Entry (RJE) products enable multi-user PRIME systems to emulate IBM, CDC, Univac, Honeywell and ICL remote job entry terminals over synchronous communication lines. PRIME's Distributed Processing Terminal Executive (DPTX) allows users to construct communication networks with PRIME and IBM-compatible equipment. PRIMENET -------- PRIMENET provides complete local and remote network communication services for all PRIME systems. PRIMENET networking software lets a user or process on one PRIME system communicate with any other PRIME system in the network without concern for any protocol details. A user can log in to any computer in the network from any terminal in the network. With PRIMENET, networking software processes running concurrently on different systems can communicate interactively. PRIMENET allows transparent access to any system in the network without burdening the user with extra commands. PRIMENET has been designed and implemented so that user interface is simple and transparent. Running on a remote system from a local node of the network or accessing remote files requires no reprogramming of user applications or extensive user training. All the intricacies and communication protocols of the network are handled by the PRIMENET software. For both the local and remote networks, PRIMENET will allow users to share documents, files, and programs and use any disk or printer configured in the network. For a local network between physically adjacent systems, PRIME offers the high-performance microprocessor, the PRIMENET Node Controller (PNC). The controller users direct memory access for low overhead and allows loosely coupled nodes to share resources in an efficient manner. The PNCs for each system are connected to each other with a coaxial cable to form a high-speed ring network, with up to 750 feet (230 meters) between any two systems. Any system in the PNC ring can establish virtual circuits with any other system, making PNC-based networks "fully connected" with a direct path between each pair of systems. The ring has sufficient bandwidth (1 MB per second) and addressing capability to accomodate over 200 systems in a ring structure; however, PRIMENET currently supports up to sixteen systems on a ring to operate as a single local network. The PRIMENET Node Controller is designed to assure continuity of operation in the event that one of the systems fails. One system can be removed from the network or restored to online status without disturbing the operations of the other system. An active node is unaware of messages destined for other nodes in the network, and the CPU is notified only when a message for that node has been correctly received. Synchronous communications over dedicated leased lines or dial-up lines is provided through the Multiple Data Link Controller (MDLC). This controller handles certain protocol formatting and data transfer functions normally performed by the operating system in other computers. The controller's microprogrammed architecture increases throughput by eliminating many tasks from central processor overhead. The communications controller also supports multiple protocols for packet-switched communications with Public Data Networks such as the United States' TELENET and TYMNET, the Canadian DATAPAC, Great Britain's International Packet Switching Service (IPSS), France's TRANSPAC, and the European Packet Switching Network, EURONET. Most Public Data Networks require computers to use the CCITT X.25 protocol to deal with the management of virtual circuits between a system and others in the network. The synchronous communications controller supports this protocol. PRIME can provide the X.25 protocol for use with the PRIMENET networking software without modification to the existing hardware configuration. PRIMENET software offers three distinct sets of services. The Inter-Program Communication Facility (IPCF) lets programs running under the PRIMOS operating system establish communications paths (Virtual circuits) to programs in the same or another PRIME system, or in other vendors' systems supporting the CCITT X.25 standard for packet switching networks. The Interactive Terminal Support (ITS) facility permits terminals attached to a packet switching network, or to another PRIME system, to log-in to a PRIME system with the same capabilities they would have if they were directly attached to the system. The File Access Manager (FAM) allows terminal users or programs running under the PRIMOS operating system to utilize files physically stored on other PRIME systems in a network. Remote file operations are logically transparent to the application program. This means no new applications and commands need to be learned for network operation. The IPCF facility allows programs in a PRIME computer to exchange data with programs in the same computer, another PRIME computer, or another vendor's computer, assuming that that vendor supports X.25. This feature is the most flexible and powerful one that any network software package can provide. It basically allows an applications programmer to split up a program, so that different pieces of the program execute on different machines a network. Each program component can be located close to the resource (terminals, data, special peripherals, etc.) it must handle, decode the various pieces and exchange data as needed, using whatever message formats the application designer deems appropriate. The programmer sees PRIMENET's IPCF as a series of pipes through which data can flow. The mechanics of how the data flows are invisible; it just "happens" when the appropriate services are requested. If the two programs happen to end up on the same machine, the IPCF mechanism still works. The IPCF offers the following advantages: 1) The User does not need to understand the detailed mechanisms of communications software in order to communicate. 2) Calls are device-independent. The same program will work over physical links implemented by the local node controller (local network), leased lines, or a packet network. 3) Programs on one system can concurrently communicate with programs on other systems using a single communications controller. PRIMENET handles all multiplexing of communications facilities. 4) A single program can establish multiple virtual circuits to other programs in the network. PRIMENET's ITS facility allows an interactive terminal to have access to any machine in the network. This means that terminals can be connected into an X.25 packet network along with PRIME computers. Terminal traffic between two systems is multiplexed over the same physical facilities as inter-program data, so no additional hardware is needed to share terminals between systems. This feature is ordinarily invisible to user programs, which cannot distinguish data entering via a packet network from data coming in over AMLC lines. A variant of the IPCF facility allows users to include the terminal handling protocol code in their own virtual space, thus enabling them to control multiple terminals on the packet network within one program. Terminals entering PRIMOS in this fashion do not pass through the usual log-in facility, but are immediately connected to the application program they request. (The application program provides whatever security checking is required.) The result is the most effective available means to provide multi-system access to a single terminal, with much lower costs for data communications and a network which is truly available to all users without the expense of building a complicated private network of multiplexors and concentrators. By utilizing PRIMENET's File Access Manager (FAM), programs running under PRIMOS can access files on other PRIME systems using the same mechanisms used to access local files. This feature allows users to move from a single-system environment to a multiple-system one without difficulty. When a program and the files it uses are separated into two (or more) systems the File Access Management (FAM)is automatically called upon whenever the program attempts to use the file. Remote file operations are logically transparent to the user or program. When a request to locate a file or directory cannot be satisfied locally, the File Access Manager is invoked to find the data elsewhere in the network. PRIMOS initiates a remote procedure call to the remote system and suspends the user. This procedure call is received by an answering slave process on the remote system, which performs the requested operation and returns data via subroutine parameters. The slave process on the remote system is dedicated to its calling master process (user) on the local system until released. A master process (user) can have a slave process on each of several remote systems simultaneously. This means that each user has a dedicated connection for the duration of the remote access activity so many requests can be handled in parallel. FAM operation is independent of the specific network hardware connecting the nodes. There is no need to rewrite programs or learn new commands when moving to the network environment. Furthermore, the user need only be logged-in to one system in the network, regardless of the location of the file. Files on the local system or remote systems can be accessed dynamically by file name within a program, using the language-specific open and close statements. No external job control language statements are needed for the program to access files. Inter-host file transfers and editing can be performed using the same PRIMOS utilities within the local system by referencing the remote files with their actual file names. REMOTE JOB ENTRY ---------------- PRIME's Remote Job Entry (RJE) software enables a PRIME system to emulate IBM, CDC, Univac, Honeywell and ICL remote job entry terminals over synchronous communication lines. PRIME's RJE provides the same communications and peripheral support as the RJE terminals they emulate, appearing to the host processor to be those terminals. All PRIME RJE products provide three unique benefits: * PRIME RJE is designed to communicate with multiple remote sites simultaneously. * PRIME RJE enables any terminal connected to a PRIME system to submit jobs for transmission to remote processors, eliminating the requirement for dedicated terminals or RJE stations at each location. * PRIME's mainframe capabilities permit concurrent running of RJE emulators, program development and production work. PRIME's RJE supports half-duplex, point-to-point, synchronous communications and operates over dial-up and dedicated lines. It is fully supported by the PRIMOS operating system. DISTRIBUTED PROCESSING TERMINAL EXECUTIVE (DPTX) ------------------------------------------------ PRIME's Distributed Processing Terminal Executive (DPTX) allows users to construct communication networks with PRIME and IBM-compatible equipment. DPTX conforms to IBM 3271/3277 Display System protocols, and can be integrated into networks containing IBM mainframes, terminals and printers without changing application code or access methods and operates under the PRIMOS operating system. DPTX is compatible with all IBM 370 systems and a variety of access methods and teleprocessing monitors: BTAM, TCAM, VTAM, IMS/VS, CIC/VS, and TSO. They provide transmission speeds up to 9600 bps using IBM's Binary Synchronous Communications (BSC) protocol. DPTX is comprised of three software modules that allow PRIME systems to emulate and support IBM or IBM compatible 3271/3277 Display Systems. One module, Data Stream Compatibility (DPTX/DSC), allows the PRIME system to emulate the operation of a 3271 on the IBM system. This enables both terminal user and application programs (interactive or batch) on the PRIME System to reach application programs on an IBM mainframe. A second module, Terminal Support Facility (DPTX/TSF), allows a PRIME system to control a network of IBM 3271/3277 devices. This enables terminal users to reach application programs on a PRIME computer. The third module, Transparent Connect Facility (DPTX/TCF), combines the functions of modules one and two with additional software allowing 3277 terminal users to to reach programs on a IBM mainframe, even though the terminal subsystem is physically connected to a PRIME system, which is connected to an IBM system. [PRIMOS offers a variety of different Communication applications. Being able to utilize these applications to their fullest extent can make life easy for a Primos 'enthusiast'. If you're a beginner with Primos, te best way to learn more , as with any other system, is to get some "hands-on" experience. Look forward to seeing some beginner PRIMOS files in the near future. -MH] ------------------------------------------------------------------------------ Special thanks to PRIME INC. for unwittingly providing the text for this article. Please forward any mail to me at Forgotten Realm BBS: 618-943-2399. ------------------------------------------------------------------------------ =============================================================================== Downloaded From P-80 International Information Systems 304-744-2253 12yrs+