LATCP$HELP.HLB  —  CREATE

1  –  LINK

    Creates the LAT data links, which are connections to LAN devices,
    such as Ethernet or FDDI (fiber distributed data interconnect)
    controllers, that you want your node to use. You must have OPER
    privilege to use this command.

    Format

      CREATE LINK  link-name

1.1  –  Parameter

 link-name

    Specifies a name for a LAT data link. A link name can have up to
    16 ASCII characters. The characters allowed are as follows:

    o  Alphanumeric characters: A-Z, a-z, 0-9

    o  A subset of the international character set: ASCII codes 192-
       253

    o  Punctuation characters: dollar sign ($), hyphen (-), period
       (.), and
       underscore (_)

    You can create a maximum of eight links on your local node.
    Use the SHOW LINK command for a list of the link names that are
    defined for your node.

1.2  –  Qualifiers

1.2.1    /DECNET

       /DECNET
       /NODECNET

    Directs LAT protocol to use the DECnet data link address (
    /DECNET) or the hardware address (/NODECNET) when starting the
    LAN controller. If you do not specify the /DECNET or /NODECNET
    qualifier, the default is that the LAT protocol will use the
    DECnet data link address.

    Note that if you enter the CREATE LINK command with the /DECNET
    qualifier and receive an error message indicating a "bad
    parameter value," it means the SCSSYSTEMID system parameter is
    set to an illegal value. To change the value of this parameter,
    use the following formula:

    (1024 * a) + n

    In the formula, a is the DECnet area and n is the DECnet computer
    number. If the value is outside the range of 1025 to 65535, the
    LAT protocol cannot start.

    When you use the /NODECNET qualifier, the LAN device driver code
    determines which address to use. For example:

    o  If SCSSYSTEMID is set to 0 but DECnet is already running on an
       Ethernet controller, the LAN device code allows LAT to use the
       same address as DECnet (AA-00-04-00-xx-xx).

    o  If SCSSYSTEMID is set to 0 and DECnet is not running, the 08-
       00-2B-xx-xx-xx address is used (a different address format is
       used depending on the vendor of your LAN controller).

    o  If the setting for SCSSYSTEMID is the same as the DECnet node
       number and DECnet is not running, the LAN device code forces
       LAT to use the AA-00-04-00-xx-xx address.

    If DECnet is configured on the system (or if the system is part
    of a cluster), SCSSYSTEMID may contain a nonzero value. This
    is a problem only when the system has 2 or more LAN controllers
    connected to the same logical LAN.

    For example, if your system has an FDDI controller and an
    Ethernet controller, your site may be configured so that the
    FDDI ring attached to the FDDI controller and the Ethernet
    segment attached to the Ethernet controller are bridged by a
    10/100 LAN bridge (FDDI-to-Ethernet). In this configuration, it
    is impossible to run LAT over both controllers.

    In such a configuration, you must run LAT and DECnet over the
    same controller if SCSSYSTEMID is not 0. If you fail to do so,
    DECnet starts first, which in turn causes the LAT startup on
    the other controller to fail. This failure occurs because LAT
    startup tries to use the AA-00-04-00-xx-xx address (the DECnet
    LAN address) but is prevented from doing so by the data link
    layer. The LAT startup fails because DECnet is already using
    this address on a different controller. (In a single logical
    LAN, all data link addresses must be unique. In this setup,
    both controllers try to use the same address, which is then not
    unique.)

    The following command (which creates the LAT link) also fails
    because the LAN driver tries to use the address based on
    SCSSYSTEMID:

    LATCP> CREATE LINK LAT$LINK_2 /NODECNET

    If SCSSYSTEMID is set to 0, configuring LAT and DECnet on
    different controllers is possible. However, in a cluster
    environment, SCSSYSTEMID cannot be set to 0.

1.2.2    /DEVICE

       /DEVICE=device-name

    Specifies the LAN controller device name for a LAT data link (for
    example, XEB0:). Only one LAT data link can be associated with a
    LAN controller. If you enter the CREATE LINK command without the
    /DEVICE qualifier, LATCP attempts to find an available controller
    by using a list of possible LAT data link device names.
    VSI advises that you specify a default device name by defining
    the LAT$DEVICE logical name.

1.2.3    /LOG

       /LOG
       /NOLOG

    Specifies whether LATCP displays a message confirming that
    the link was created. If you do not specify the /LOG or /NOLOG
    qualifier, the default is that no message will be displayed.

1.2.4    /STATE

       /STATE=option

    Specifies whether the link will be available for use. STATE can
    have two options:

    ON    Specifies that the created link will be available for use
          with the LAT protocol running.
    OFF   Specifies that the created link will not be available for
          use.

    If you do not specify the /STATE=option qualifier, the default is
    that the created link will be available for use (ON).

1.3  –  Example

  LATCP> CREATE LINK NETWORK_A /DEVICE=XEB0: /STATE=ON

      The CREATE LINK command in this example creates an Ethernet
      link named NETWORK_A. It specifies the Ethernet controller
      device XEB0 for that link. The link will be available for use.

2  –  PORT

    Creates a logical port on your local node that connects with a
    remote device on a terminal server. Alternatively, this command
    creates a logical port on your local node that connects with a
    specific service. The service can be offered by a terminal server
    or associated with one or more dedicated ports on a remote LAT
    service node.

    You must have OPER privilege to use this command.

    Format

      CREATE PORT  [port-name]

2.1  –  Parameter

 port-name

    Specifies the port name in the form LTAn:, where n is a unique
    number from 1 through 9999. If the port you specify already
    exists, LATCP returns the following error message:

    %LAT-W-CMDERROR, error reported by command executor
    -SYSTEM-F-DUPLNAM, duplicate name

    If you do not specify the port name, you must specify the
    /LOGICAL qualifier.

                                  NOTES

       When creating a port, note the following:

       o  VSI recommends that you assign a logical name when
          creating a port, instead of specifying a specific LTA
          device.

       o  You cannot use the CREATE PORT and SET PORT commands,
          along with the DCL command SET TERMINAL, to change the
          characteristics of a DECserver port unless there is an
          existing LAT connection to that DECserver.

2.2  –  Qualifiers

2.2.1    /APPLICATION

    Specifies that a logical port on your node is an application
    port. It can be used to connect to a remote device (typically a
    printer) on a terminal server or to a dedicated port on another
    LAT service node.

    If you do not specify a port type, the default port type is
    APPLICATION.

                                   NOTE

       By default, LATCP creates application LAT devices with
       the HANGUP terminal characteristic. However, if you want
       to apply the NOHANGUP characteristic to application LAT
       devices, you can do so by entering specific LATCP and DCL
       commands. For example:

       $ LCP :== $LATCP
       $ LCP CREATE PORT LTA1234
       $ LCP SET PORT LTA1234 /APPLICATION /NODE=terminal_server /PORT=server_port
       $ SET TERMINAL LTA1234 /PERMANENT /NOHANGUP

       Note that you can insert the SET TERMINAL command in the
       SYS$MANAGER:LAT$SYSTARTUP.COM file (enter the command for
       each LAT device that requires the NOHANGUP characteristic).

2.2.2    /DEDICATED

    Specifies that a logical port on your local node is dedicated
    to an application service. When users on a terminal server (or
    on another node that supports outgoing connections) request
    a connection to this service name, they are connected to the
    dedicated port. See the OpenVMS I/O User's Reference Manual for a
    description of programming an application service.

    After creating a dedicated port on a node, use the SET PORT
    /SERVICE command to map this port to a service.

2.2.3    /LIMITED

    Specifies that a logical port on your local node is limited to
    a service in the same way a port created using the /DEDICATED
    qualifier is dedicated to an application service. The difference
    is that ports created using the /LIMITED qualifier are under the
    control of the system login image (LOGINOUT.EXE) instead of an
    application program (a user who connects to a limited service and
    is assigned to a limited port receives the "Username:" prompt).

    Using the /LIMITED qualifier, you can create a limited number
    of ports and map them to a specific service offered by the host
    system. If users are logged in to all of the limited ports for
    the service, no more connections are allowed to that service
    (terminal server users receive a "service in use" message).

2.2.4    /LOG

       /LOG
       /NOLOG

    Specifies whether LATCP displays a message confirming that
    the port was created. If you do not specify the /LOG or /NOLOG
    qualifier, the default is that no message will be displayed.

2.2.5    /LOGICAL

       /LOGICAL=(NAME=logical-name[,TABLE=table][,MODE=mode])

    Specifies a logical name to be associated with the actual name of
    the created port. You must specify a logical name if you do not
    specify a port name.

                                   NOTE

       If you have sufficient privileges to create a port, but lack
       the privilege to assign a logical name, the port will still
       be created.

    You can specify one of the following options for the TABLE
    keyword:

    GROUP      Places the logical name in the group logical name
               table. You must have GRPNAM or SYSPRV privilege to
               place the logical name in the group logical name table.
    JOB        Places the logical name in the jobwide logical name
               table.
    PROCESS    Places the logical name in the process logical name
               table. This is the default.
    SYSTEM     Places the logical name in the system logical name
               table. You must have SYSNAM or SYSPRV privilege to
               place a name in the system logical name table.

    You can also specify the name of a specific table. For example,
    you could specify LNM$PROCESS, which would be the equivalent of
    specifying PROCESS.

    Options for the MODE keyword are:

    EXECUTIVE   Creates an executive mode logical name. You must have
                SYSNAM privilege to create an executive mode logical
                name.
    SUPERVISOR  Creates a supervisor mode logical name.
    USER        Creates a user mode logical name.

    The access mode associated with the logical name is determined
    by maximizing the access mode of the caller with the access mode
    specified by the MODE keyword: the mode with the lower privilege
    is used.

    You cannot specify an access mode with a privilege higher than
    that of the table containing the logical name. However, if your
    process has SYSNAM privilege, then the specified access mode is
    associated with the logical name regardless of the access mode of
    the caller.

    If you omit the MODE keyword, the access mode of the caller is
    associated with the logical name.

    You can also create the port as a limited port, using the
    /LIMITED qualifier.

2.3  –  Examples

    1.LATCP> CREATE PORT LTA22: /APPLICATION

      The CREATE PORT command in this example creates an application
      port named LTA22: on a service node. You can associate the port
      with a specific printer on a terminal server (use the SET PORT
      /NODE /PORT command) or with a set of printers on a terminal
      server (use the SET PORT /NODE /SERVICE command). Or, you can
      associate the port with a dedicated port on a remote service
      node. In this case, use the SET PORT /NODE /SERVICE command,
      where the /SERVICE qualifier specifies an application service
      associated with a dedicated port on the remote node. See the
      examples for the SET PORT command.

    2.LATCP> CREATE PORT LTA21: /DEDICATED

      The CREATE PORT command in this example creates the LTA21:
      port. It will be used as a dedicated port that offers a
      specific service rather than a general timesharing service.

    3.LATCP> CREATE PORT /LOG /APPLICATION -
      _LATCP> /LOGICAL=(NAME=MAIL_PORT, TABLE=PROCESS, MODE=SUPERVISOR)

      The CREATE PORT command in this example creates an application
      port. It assigns the name of the new port to the specified
      logical name (MAIL_PORT). The logical is created as a
      supervisor mode logical name in the LNM$PROCESS_TABLE logical
      name table. LATCP displays a confirmation message.

    4.$ LCP :== $LATCP
      $ LCP CREATE SERVICE/LIMITED ONLY_ONE
      $ LCP CREATE PORT/LIMITED LTA1234:
      $ LCP SET PORT LTA1234: /SERVICE=ONLY_ONE

      This series of commands creates a limited service that allows
      only one user to log in to the system through that service.
      When a user connects to service ONLY_ONE by responding to the
      terminal server prompt (Local>), the user is assigned port
      LTA1234 and then prompted for the user name. Any user who
      attempts to connect to the same service while LTA1234 has a
      user logged in receives the "service in use" message.

3  –  SERVICE

    Creates a service on a service node. You must have OPER privilege
    to use this command.

    Format

      CREATE SERVICE  [service-name]

3.1  –  Parameter

 service-name

    Specifies a LAT service name. By default, a service name is the
    name of the local node you defined with the SET NODE command.

    The service name can be from 1 to 16 ASCII characters in length.
    The characters allowed are as follows:

    o  Alphanumeric characters: A-Z, a-z, 0-9

    o  A subset of the international character set: ASCII codes 192-
       253

    o  Punctuation characters: dollar sign ($), hyphen (-), period
       (.), and underscore (_)

3.2  –  Qualifiers

3.2.1    /APPLICATION

    Specifies that the created service is an application service. An
    application service offers a specific application on the service
    node rather than a general interactive service. You can define a
    dedicated port for the service by using the CREATE PORT and SET
    PORT commands.

3.2.2    /IDENTIFICATION

       /IDENTIFICATION[="identification-string"]

    Describes and identifies a service. Service nodes include the
    identification string in service announcements. A service node
    announces its services at regular intervals established with the
    SET NODE command. Entering the LATCP SHOW NODE command or the
    DECserver SHOW NODE command generates a display that includes
    this identification string. By default, the identification string
    is a translation of SYS$ANNOUNCE.

    You cannot specify more than 64 ASCII characters in an
    identification string (a SYS$ANNOUNCE longer than that will be
    truncated to the first 64 characters). Enclose the string in
    quotation marks (").

3.2.3    /LIMITED

    Specifies that the service is a limited service, using devices
    assigned the limited characteristic and associated with (mapped
    to) this limited service. This qualifier is used in conjunction
    with the SET PORT /LIMITED command (see example).

3.2.4    /LOG

       /LOG
       /NOLOG

    Specifies whether LATCP displays a message confirming that the
    service was created. If you do not specify the /LOG or /NOLOG
    qualifier, the default is that no message will be displayed.

3.2.5    /STATIC_RATING

       /STATIC_RATING=rating
       /NOSTATIC_RATING

    Enables or disables dynamic service ratings. A dynamic service
    rating means that a LAT algorithm calculates the availability
    of a service dynamically, based on the overall level of activity
    of the node that offers the service and the amount of memory.
    When a terminal server or node requests a connection to a service
    that is offered on two or more service nodes, the requesting
    node selects the service node with the highest (most favorable)
    service rating. This selection process is called load balancing.

    The dynamic service rating, which is the default, is usually
    adequate for efficient load balancing on the LAT network.
    However, when necessary, you can use the /STATIC_RATING qualifier
    to disable dynamic service ratings so that you can specify a
    static (fixed) rating. That static rating value does not change
    until the dynamic service rating is reenabled.

    Use the static rating to direct users away from or toward your
    node temporarily. Static ratings range from 0 to 255. Specify a
    low value to make the local service node less likely to be used;
    specify a high value to make the local service node more likely
    to be used.

    If you do not specify either the /STATIC_RATING or /NOSTATIC_
    RATING qualifier, the default is that the LAT software uses the
    dynamic service rating.

    Limited and application services do not rely exclusively on
    the dynamically calculated service rating. Instead, they use
    a portion of the dynamic rating based on how many ports are
    available for the service. For example, if a limited service has
    50% of its ports available, the dynamic service rating will be
    scaled, halved, and then added to 105. When ports are available,
    the rating will always be above the value 105.

    When all ports for a limited or application service are in use,
    the rating will be based on the scaled dynamic rating and the
    number of free queue slots on the local node. The rating will
    always be less then 90.

    This rating procedure for limited and application services
    follows the terminal server rating algorithm for services and
    available ports that the service offers, while at the same time
    taking into account the availability of the node (which is the
    factor used to calculate the dynamic rating).

    If your system is licensed for a specific number of units (where
    only a fixed number of users can log in to the system regardless
    of how the login limit is set), then all dynamic ratings become 0
    when all OpenVMS license units have been consumed. (This forces
    all node service ratings to the lowest possible value when logins
    are not possible because all OpenVMS license units have been
    consumed.)

    Note as well that the LAT software transmits a service
    announcement message when a user logs in to or out of the system.
    This allows the system to more quickly provide information
    about service rating changes that result from a login or logout
    operation.

3.3  –  Examples

    1.LATCP> CREATE SERVICE/STATIC_RATING=195 SALES

      The CREATE SERVICE command in this example creates the service
      SALES on a service node. This command assigns a static rating
      of 195 so terminal servers (and nodes that support outgoing
      connections) can assess the availability of services on the
      node.

    2.LATCP> CREATE SERVICE/APPLICATION GRAPHICS

      This command creates the service GRAPHICS on the local node.
      Use the CREATE PORT/DEDICATED and SET PORT/SERVICE=GRAPHICS
      commands to create a port that is dedicated to this service.

    3.$ LCP :== $LATCP
      $ LCP CREATE SERVICE/LIMITED ONLY_ONE
      $ LCP CREATE PORT/LIMITED LTA1234:
      $ LCP SET PORT LTA1234: /SERVICE=ONLY_ONE

      This series of commands creates a limited service that allows
      only one user to log in to the system through that service.
      When a user connects to service ONLY_ONE by responding to the
      terminal server prompt (Local>), the user is assigned port
      LTA1234 and then prompted for the user name. Any user who
      attempts to connect to the same service while LTA1234 has a
      user logged in receives the "service in use" message.
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