DTJ Number 3 September 1987 - Digital Technical Journals

The DECnetjSNA Gateway ProductDECnetSYSTEMI RINPUT JOBFILESJOB WORKSTATION DECnet' AcE_-_______oPE__-RAoR-__________ --;---OUTPUT FROMPRINT/PUNCHSTREAMS1F LE--(DECnetNETWORK)ICDEC netSYS TEMco NTAININGGAT EWAYRJESERVERISNAPROTOCOLEMULATORIjSNA/SDLCDATA LINKCONTROLFigure 10Structure of Remote jo b Entry Fa cilityThe functional layer for DDXF handles both theDIA protocols and the conve rsion to and fromDCA document formats. The functional layeruses the LU6 .2 component of the SNA interfacelayer. Internally, the LU6.2 interface uses the servicesof the extended-mode interface, which inturn is supported by the basic-mode interface.The basic mode of the SNA interface layer must inturn communicate with the common networklayer; the latter is located in the DECnetjSNAGateway node, and communication takes placeusing the SNA gateway access mechanism discussedearlier.The common network layer uses the servicesof the SDLC module in the data link layer. Inturn, this layer uses whichever physical layermodule is appropriate to the communicationshardware.R]E as an Example of the Server ModelThe functional and SNA interface layers for RJEboth appear in the RJ E server process, which executesin the gateway. Figure 10 depicts the structureof RJE. The functional layer converts data toand from the formats used by SNA remote jobentry. This layer uses the DECnet remote fileaccess facility to read and write files located onthe DECnet host node. The SNA interface layerimplements the LUI protocol for remote workstations.The RJE SNA interface layer uses thecommon interface layer software in the gatewaynode, as does the SNA gateway module.The end user communicates with the RJ Eserver by using one of two command interfaces(workstation operator or unprivileged user) residenton the DECnet host node. These interfaceprograms use a private protocol, operated over aDECnet logical link, to pass commands to theserver .46Digital TecbnicaJJournaJNo. 3 September 1986