Updated: 11 December 1998

OpenVMS System Manager's Manual

The InfoServer client software fails to start on a system where DECnet has been started and subsequently stopped. The following message will be found in the file SYS$MANAGER:ESS$STARTUP.LOG:

%ESS-I-NONET ESS started before DECnet. 4-MAR-1998 16:36:39.29

If the InfoServer client must be started at this point, the LASTport transport can be started with the Last Control Program using the following command:

$ MCR ESS$LASTCP LASTCP> START

This command will start the transport. You may now execute the InfoServer client startup:

$ @SYS$STARTUP:ESS$STARTUP DISK

Because the transport is already started, the startup will run successfully.

23.5.5 Multiple Controllers Configured But Not All Attached to Media (Alpha Only)

If you have multiple Ethernet and FDDI controllers configured on your OpenVMS Alpha system, you might experience problems with the InfoServer client transport (LASTport) under either of the following conditions:

• Not all of the Ethernet and FDDI controllers are connected to network cabling.
• An FDDI controller is connected to the network cabling, but the FDDI ring is not functional; for example, some FDDI hardware may be powered down or broken.

Problems can range from not being able to access all the services available on the network, if you have four or more controllers configured, to a system crash.

To avoid these problems, specify only the controllers that are attached to media. Compaq recommends that you do this by first editing your SYS$STARTUP:ESS$LAST_STARTUP.DAT data file to specify only the controllers that are attached and then restarting your system.

With certain controller configurations, if you specify controllers that are not attached, your system might crash when you issue the following command sequence:

$ MC ESS$LASTCP LASTCP> STOP

An example of how to edit the SYS$STARTUP:ESS$LAST_STARTUP.DAT file follows. The unedited file is shown first, followed by an edited file.

!++ ! This file will be used to set the appropriate LASTCP qualifiers. The following ! LASTCP qualifiers: ALL_CONTROLLERS, CHECKSUM, TRANSMIT_QUOTA, or SLOW_MODE ! can be set by using the following statement format: ! LASTCP qualifier = 1 to enable e.g. SLOW_MODE = 1 enables SLOW_MODE ! LASTCP qualifier = 0 to disable e.g. SLOW_MODE = 0 disables SLOW_MODE ! The remaining LASTCP qualifiers will require the appropriate value settings. ! DEVICE = (list-of-devices) ! TIMEOUT = n minimum interval in seconds ! CIRCUIT_MAXIMUM = n maximum number of nodes ! GROUP = n Group number ! NODE_NAME = name Node name ! CONTROLLERS = ([{controller letter,}...]) Controller list ! TRANSMIT_QUOTA = n Number of transmit buffers !-- ALL_CONTROLLERS = ON

The edited SYS$STARTUP:ESS$LAST_STARTUP.DAT file follows. This example assumes you have ESA, ETA, EXA, EZA controllers configured on your system and that only the ESA controller is attached to the Ethernet wire.

!++ ! This file will be used to set the appropriate LASTCP qualifiers. The following ! LASTCP qualifiers: ALL_CONTROLLERS, CHECKSUM, TRANSMIT_QUOTA, or SLOW_MODE ! can be set by using the following statement format: ! LASTCP qualifier = 1 to enable e.g. SLOW_MODE = 1 enables SLOW_MODE ! LASTCP qualifier = 0 to disable e.g. SLOW_MODE = 0 disables SLOW_MODE ! The remaining LASTCP qualifiers will require the appropriate value settings. ! DEVICE = (list-of-devices) ! TIMEOUT = n minimum interval in seconds ! CIRCUIT_MAXIMUM = n maximum number of nodes ! GROUP = n Group number ! NODE_NAME = name Node name ! CONTROLLERS = ([{controller letter,}...]) Controller list ! TRANSMIT_QUOTA = n Number of transmit buffers !-- ALL_CONTROLLERS = OFF DEVICE = (ESA)

If PATHWORKS or Remote System Manager (RSM) or both are installed, the InfoServer Client for OpenVMS startup must be run before the startup for PATHWORKS or RSM, or both. For example:

$ @SYS$MANAGER:STARTNET . . . $ @SYS$STARTUP:ESS$STARTUP DISK TAPE $ @SYS$STARTUP:PCFS_STARTUP $ @SYS$STARTUP:RSM$SERVER_STARTUP

InfoServer Client for OpenVMS software provides device drivers and control programs that are shared by both the PATHWORKS and RSM products. All InfoServer Client for OpenVMS components are prefixed with ESS$. The drivers and control programs supplied with InfoServer Client for OpenVMS software provide all necessary support for both PATHWORKS and RSM in addition to InfoServer Client support. You must execute the InfoServer Client for OpenVMS startup in the site-specific startup before executing either the PATHWORKS or RSM startup procedure.

23.5.7 Startup Restrictions: SYSMAN

You cannot start InfoServer Client for OpenVMS from a subprocess. Because the OpenVMS System Management utility (SYSMAN) uses subprocesses to complete its tasks on remote nodes, SYSMAN cannot be used to execute the SYS$STARTUP:ESS$STARTUP procedure.

23.5.8 User Account Requirements

To work with InfoServer Client for OpenVMS software, user accounts on your system must have the following privileges and quotas:

• GRPNAM privilege to use the /GROUP qualifier of the LADCP command BIND; SYSNAM privilege to use the command's /SYSTEM qualifier.
• At a minimum, default UAF account quotas.

Refer to the AUTHORIZE section in the OpenVMS System Management Utilities Reference Manual for an explanation of how to verify and change account privileges and quotas.

23.5.9 System Parameter MAXBUF Requirement

To use all the LASTport Control Program (LASTCP) utility's SHOW functions, you must set the value of the system parameter MAXBUF to 32000 or greater.

23.6 Understanding LADCP Utility Functions

Use the LAD Control Program (LADCP) utility to configure and control the LASTport/Disk and LASTport/Tape protocols on OpenVMS systems. OpenVMS systems that use LASTport/Disk and LASTport/Tape services are called client systems. You can use LADCP to perform the following tasks:

• Establish bindings to services. A binding creates a new DADn: virtual disk unit or a new MADn: virtual tape unit on the local OpenVMS system.
• Remove bindings to services.

You can control service access by using a service access password. You can also write-protect services. In this case, local OpenVMS users of a DADn: or MADn: device unit receive an error if they attempt a write operation to the unit.

The protocols allow you to access storage devices that reside on an InfoServer system as though they are locally connected to your OpenVMS system. Thus, several OpenVMS client systems can share the same read-only media, eliminating the need for duplicate drives and media.

DADn: and MADn: device units are also referred to as virtual device units. They represent the local OpenVMS context for a volume that resides on a remote server. The OpenVMS driver that controls the DADn: units is called ESS$DADDRIVER. The OpenVMS driver that controls the MADn: units is called ESS$MADDRIVER.

The LASTport/Disk and LASTport/Tape protocols depend on the LASTport transport. The ESS$STARTUP.COM command procedure in SYS$STARTUP automatically loads ESS$DADDRIVER and ESS$MADDRIVER as well as ESS$LASTDRIVER, the LASTport transport driver.

To invoke LADCP, enter the following command:

$ RUN SYS$SYSTEM:ESS$LADCP LADCP>

You can enter LADCP commands at the LADCP> prompt.

You can also execute a single LADCP command by using a DCL string assignment statement, as shown in the following example:

$ LADCP :== $ESS$LADCP $ LADCP BIND CD_DOC_00661 /NOWRITE

LADCP executes the BIND command and returns control to DCL command level.

To exit LADCP, enter EXIT or press Ctrl/Z after the LADCP> prompt.

23.6.2 LADCP Command Summary

Table 23-3 summarizes LADCP commands and their functions.

Table 23-3 Summary of LADCP Commands

Command	Function
BIND	Establishes a service binding and creates a device unit
DEALLOCATE	Terminates any active connection to a service without deleting the unit control block (UCB)
EXIT	Returns the user to DCL command level
HELP	Displays help text for LADCP commands
SHOW SERVICES	Displays services offered by InfoServer systems on the LAN
UNBIND	Terminates an established service binding

LADCP provides a Help facility that contains information about each LADCP command, including parameters, qualifiers, and examples of its use. For detailed descriptions of LADCP commands, refer to the InfoServer Client for OpenVMS LASTCP and LADCP Utilities manual.

23.6.3 Making InfoServer Devices Available Automatically

You can make remote InfoServer devices available on your system each time the system boots. To do so, add to SYSTARTUP_VMS.COM a series of LADCP BIND commands. For more information about the BIND command, refer to the InfoServer Client for OpenVMS LASTCP and LADCP Utilities manual.

How to Perform This Task

1. Edit SYSTARTUP_VMS.COM and find the command that starts InfoServer Client software. For example:

   @SYS$STARTUP:ESS$STARTUP DISK TAPE

   
   This command starts the software with disk and tape functions.

2. Add the following command to invoke LADCP:

   $ RUN SYS$SYSTEM:ESS$LADCP

3. Immediately after this command, add BIND commands in the following format to make InfoServer compact discs or read/write disks available as virtual device units:

   BIND [/QUALIFIER,...] service-name

   
   To make tape devices available, you must specify the /TAPE qualifier in addition to any other desired qualifiers:

   BIND/TAPE [/QUALIFIER,...] service-name

   
   For service-name, specify the name of the InfoServer device service. Usually a service name is the label of the volume to which the InfoServer system is providing access. For more information about the BIND command, refer to the InfoServer Client for OpenVMS LASTCP and LADCP Utilities manual.

4. Add an EXIT command to exit LADCP.
5. Add MOUNT commands in the following format to make available as public devices the virtual device units created in the previous step:

   MOUNT/SYSTEM/NOASSIST device-name volume-label

   
   For device-name, specify the name of the device. For volume-label, specify a volume label to assign to the device. For more information about the MOUNT command, refer to the MOUNT section in the OpenVMS System Management Utilities Reference Manual.

Example

The following commands, executed in SYSTARTUP_VMS.COM, start the InfoServer Client software and make available to client systems the InfoServer device DAD$OPENVMSV72.

. . . $ @SYS$STARTUP:ESS$STARTUP DISK $ RUN SYS$SYSTEM:ESS$LADCP BIND OPENVMSV72 EXIT $ MOUNT/SYSTEM/NOASSIST DAD$VMS055 VMS055 . . .

In this example, the OpenVMS Version 7.2 consolidated distribution (CONdist) compact disc loaded in a compact disc drive connected to an InfoServer system, is made available on the server as a virtual device unit and mounted as a public device.

This chapter describes how the LAT software works and the tasks you must perform to implement and manage the LAT software on your system.

Information Provided in This Chapter

This chapter describes the following tasks:

Task	Section
Starting up the LAT protocol	Section 24.5
Customizing LAT characteristics	Section 24.6
Creating a service	Section 24.6.1
Setting up ports	Section 24.6.2
Setting up printers	Section 24.6.2.1
Setting up special application services	Section 24.6.2.2
Enabling queued incoming requests	Section 24.6.3
Enabling outgoing LAT connections	Section 24.6.4
Managing the LATACP database size	Section 24.7

This chapter explains the following concepts:

Concept	Section
LAT protocol	Section 24.1
LAT network	Section 24.2
LAT configurations	Section 24.3
LAT Control Program utility	Section 24.4

24.1 Understanding the LAT Protocol

The operating system uses the LAT (local area transport) software to communicate with terminal servers and other systems within a local area network (LAN). Terminal servers are communication devices dedicated for connecting terminals, modems, or printers to a LAN. They offer the following features:

• Provide a cost-effective method of connecting many user terminals to a computer
• Save on cable requirements
• Maximize the number of devices that can access a computer

With the LAT software, which implements the LAT protocol, the operating system can offer resources, or services, that the terminal servers can access. A system that offers LAT services is called a service node. In addition, nodes can access LAT services by enabling outgoing connections (using LATCP) and using the DCL command SET HOST/LAT. (In the remainder of this chapter, "servers" refers both to dedicated terminal servers and to nodes that allow outgoing access to other LAT services.)

A LAT service can consist of all the resources of a computer system, or it can be a specific resource on a computer system, such as an application program. You can set up your system as a general timesharing service, meaning that all of its resources are available to users in the LAN, or you can restrict access to a specific service (application program) on the system. This chapter and the OpenVMS I/O User's Reference Manual outline the procedure you use to set up access to a dedicated application program.

24.1.1 How the LAT Protocol Works

The LAT protocol allows the terminal servers and computers to communicate within a LAN, such as the Ethernet or the Fiber Distributed Data Interconnect (FDDI). The LAT protocol matches terminals and other devices to the computing resources (services) of the LAN. Because LAT terminals are not connected directly to the computer (service node) they are accessing, the local server must listen for service requests from its terminals and be able to match the terminals with computers that provide the desired services.

Using the LAT protocol, then, the operating system announces its available services over the LAN. Servers listen to the LAN announcements and build a database of service information so that they can locate an appropriate system when a user terminal requests computing services. For example, a user terminal might request general processing service or a data entry program on the operating system. A server uses the LAT protocol to establish and maintain a connection between the requesting terminal and the operating system.

Sometimes the operating system can request services from a terminal server. The LAT protocol allows systems to ask for connections to printers or other devices attached to a terminal server.

24.1.2 Advantages of the LAT Protocol

Using the LAT protocol on your system has many advantages:

• The LAT protocol lets you make the resources of any computer on a local area network available to any user in that network.
• In addition to general processing resources, you can set up terminals, printers, and modems so they are available from multiple systems in the local area network. This lets you efficiently use these resources and keep them available even if one of the systems in the network must be shut down.
• You can also set up application programs, such as data entry programs or news services, as resources. When a user requests a connection to the resource, the LAT protocol sets up a connection directly to the application program. No login procedure is necessary.
• The LAT protocol provides load balancing features and recovery mechanisms so users get the best, most consistent service possible. In their broadcast messages, systems rate the availability of their services so that servers can establish connections to computing resources on the least busy node. If a node becomes unavailable for any reason, the servers attempt to provide access to alternate services.
• Users can establish multiple computing sessions on their terminals, connecting to several different computers and switching easily from one computing session to another. After switching from one session to another, users can return to the previous session and pick up where they left off. This saves users the time normally required to close out and reopen files or accounts and to return to the same point in a session.
• Finally, the LAT protocol can provide improved system performance. Because the servers bundle messages onto a single LAN interface, a server interface decreases the network traffic and reduces the number of computer interrupts realized in systems where terminals, modems, and printers each have a physical connection to the computer.

A LAT network is any local area network where terminal servers and operating systems use the LAT protocol. A LAT network can coexist on the same LAN with other protocols. The LAT protocol, which operates on both terminal servers and the operating systems, is designed to ensure the safe transmission of data over the LAN.

The LAT network consists of the following components:

Component	For More Information
Service nodes	Section 24.2.1
Terminal server nodes	Section 24.2.2
Nodes allowing outgoing connections	Section 24.2.3
LAN cable	Section 24.2.4

Service nodes supply computing resources for the local network, while terminal server nodes (or nodes allowing outgoing connections) port their terminals, modems, or printers to those resources upon request from a user terminal or an application program.

Note that in a LAT network, nodes that access services are often referred to as master nodes, which distinguishes them from nodes that only provide services.

You can use the LAT Control Program (LATCP) to configure the LAT characteristics for your system. LATCP allows you to set up your system to support:

• Incoming access only
• Outgoing access only
• Both incoming and outgoing access

The systems that support incoming LAT connections are service nodes. (Using LATCP, you can also set up your system so that it supports neither incoming nor outgoing access.)

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