Software Product Description ________________________________________________________________ PRODUCT NAME: DECserver 250 for VMS, Version 2.0 SPD 25.J5.01 DESCRIPTION The DECserver 250 is a network server for printers for Ethernet Local Area Networks. The DECserver 250 provides a convenient method to connect logically the following: o Two Digital asynchronous parallel printers (using Dataprod- ucts parallel interface standard) o Three Digital asynchronous serial printers o A Digital asynchronous serial printer or terminal with modem control to one or more service nodes (hosts) on an Ethernet The DECserver 250 implements the Local Area Transport (LAT) protocol for communication with service nodes that implement this protocol on the same Ethernet. Software that runs on the DECserver 250 is down-line loaded over the network from a Phase IV DECnet load host. DECserver 250 Option The DECserver 250 hardware consists of a single box that pro- vides the following: o Two Digital Parallel printer ports, each of which uses a male 37 pin connector o Four EIA RS-232-C/CCITT V.24 asynchronous line interfaces for connecting three serial printers and one serial printer or terminal DIGITAL November 1990 AE-NH91B-TE DECserver 250 for VMS, Version 2.0 SPD 25.J5.01 o Ethernet interface transceiver port Features Connection Management A print symbiont on VMS service nodes initiates connections to asynchronous printers connected to DECserver 250 ports. Users can establish a logical connection from any service node that implements the LAT protocol on the same Ethernet LAN. The terminal connected to the server can be used to make multiple connections to the same or to different service nodes on the Ethernet. Only one connection per asynchronous printer can be made. Load Balancing The DECserver 250 offers load balancing, which is a function that dynamically spreads the user load evenly among service nodes that offer the same service. The LAT Control Program (LATCP) is used by the System Manager to establish service definitions. On-line HELP Facility A full on-line reference HELP facility, with tutorial HELP fea- ture, is available on the printer/terminal port. The remaining ports do not have access to the HELP facilities. Permanent Characteristics The DECserver 250 maintains permanent characteristics in non- volatile memory, which is retained even when the power is dis- connected. Port Characteristics Configuration 2 DECserver 250 for VMS, Version 2.0 SPD 25.J5.01 Characteristics governing the operation of the DECserver 250 ports can be displayed interactively from the printer/terminal port when connected to a terminal. Characteristics other than permanent may be setup by the user or Server Manager. Port Access Port access is the characteristic which determines how a port may access or be accessed by interactive users and service nodes. The printer/terminal port of the DECserver 250 is the only asynchronous port with modem control. This port is the only one available for terminal connection and the only one which offers these access modes: o Local - Designed for the interactive terminal to allow the device attached to the port to communicate directly with the server. o Service - Service Mode is used for communications between the server and service nodes. All other ports use remote access, which is designed for ap- plications driven devices such as asynchronous printers, which are allocated by a service node process. This allows the im- plementation of certain shared printers by multiple service nodes. Refer to the System Support Addendum (SSA 25.J5.01-x) for the list of printers, terminals, and modems supported. DECserver 250 Operation The DECserver 250 ROM-based firmware provides the necessary maintenance operation protocols for down-line loading DECserver 250 software from a Phase IV DECnet load host over the Ethernet into server memory. All self-test diagnostics are DECserver 250 ROM-based and are executed prior to a Load request. DECserver 250 Configuration and Performance 3 DECserver 250 for VMS, Version 2.0 SPD 25.J5.01 The performance of a given server is a function of the expected network traffic, the load on hosts to which ports are connected, and resultant processing pursuant to the dedicated function of the unit. Thus performance depends on several factors: o Number of ports in use o Number of host systems with active connections to the server o Printer speeds o Terminal connection/speed on the printer/terminal port o User applications o Number and size of host buffers o Server workload o Network and host loading In terms of throughput to the printer ports, the DECserver 250 supports the equivalent of two 1200 LPM printers, or one 2000 LPM printer running at full speed, or aggregate transfer rates of 19,200 baud on two of the serial ports and 9600 baud on the remaining two serial ports. HARDWARE REQUIREMENTS VAX, MicroVAX, or VAXstation configuration as specified in the System Support Addendum (SSA 25.J5.01-x). SOFTWARE REQUIREMENTS * VMS Operating System DECnet-VAX * Refer to the System Support Addendum (SSA 25.J5.01-x) for the availability and required versions for prerequisite/optional software. ORDERING INFORMATION 4 DECserver 250 for VMS, Version 2.0 SPD 25.J5.01 Software Licenses: QL-VTMA*-** Software Media: QA-VTMA*-** Software Documentation: QA-VTMA*-GZ Software Product Services: QT-VTMA*-** * Denotes variant fields. For additional information on avail- able licenses, services and media, refer to the appropriate price book. SOFTWARE LICENSING This software is furnished under the licensing provisions of Digital Equipment Corporation's Standard Terms and Conditions. For more information about Digital's licensing terms and poli- cies, contact your local Digital office. SOFTWARE PRODUCT SERVICES A variety of service options are available from Digital. For more information, contact your local Digital office. SOFTWARE WARRANTY Warranty for this software product is provided by Digital with the purchase of a license for the product as defined in the Software Warranty Addendum of this SPD. [TM] The DIGITAL Logo, DECserver, DECnet, VMS, MicroVAX, VAXs- tation, VAXserver and VMS are trademarks of Digital Equip- ment Corporation. 5