LATCP SET — VMS 5.4-3
Additional information available:
LINK
Changes the characteristics of Ethernet links. You must have OPER
privilege to use this command.
Format
SET LINK link-name
Additional information available:
ParameterCommand QualifiersExample
Parameter
link-name
Specifies the name for an Ethernet 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 ($), hyphen (-), period
(.), and underscore (_)
The SHOW LINK command displays the names of the links defined for
a VMS node.
Command Qualifiers
Additional information available:
/LOG
/LOG
/NOLOG
Specifies whether LATCP displays a message confirming that the
link's characteristics were modified. The default is /NOLOG.
/STATE
/STATE=option
Specifies availability of the link for use. There are two options
for STATE:
ON Specifies that the link will be available for use with
the LAT protocol running. This is the default.
OFF Specifies that the link will not be available for use.
Example
LATCP> SET LINK NETWORK_A /LOG
The SET LINK command in this example directs LATCP to start
the controller for link Network_A and to then display a
confirmation message.
NODE
Specifies the LAT characteristics of your local VMS node. You must
have OPER privilege to use this command.
Format
SET NODE [node-name]
Additional information available:
Parameter
node-name
Specifies a node name for your local VMS node. By default, the
node name is the translation of SYS$NODE. A LAT node name should
be the same as the DECnet node name. If the VMS node is not
running DECnet but will be in the future, it is recommended that
you define SYS$NODE and use it for both DECnet and LAT node names.
A node name can be from 1 to 16 ASCII characters. The characters
allowed are as follows:
o Alphanumeric characters: A-Z, a-z, 0-9
o A subset of the international character set: ASCII codes 192-
253
o Punctuation characters: dollar sign ($), hyphen (-), period
(.), and underscore (_)
Qualifiers
Additional information available:
/CIRCUIT_TIMER/CONNECTIONS/CPU_RATING/DEVICE_SEED
/GROUPS/IDENTIFICATION/KEEPALIVE_TIMER/LOG/MULTICAST_TIMER
/NODE_LIMIT/RETRANSMIT_LIMIT/SERVICE_RESPONDER
/SESSION_LIMIT/STATE/UNIT_NUMBER_MAXIMUM/USER_GROUPS
/CIRCUIT_TIMER
/CIRCUIT_TIMER=msecs
Allows you to control the interval in milliseconds (ms) between
messages sent from the local node to other service nodes or
terminal servers while a connection to those nodes are active.
Use this qualifier only if your node allows outgoing connections
(/CONNECTIONS=OUTGOING_ONLY or /CONNECTIONS=BOTH).
A low value for the interval decreases the response time for the
port but increases the demand on service nodes. Set the circuit
timer in the range of 10 to 1000 milliseconds. The default value
of 80 milliseconds gives a generally acceptable response time
while creating a moderately low overhead on the service nodes. The
value for the circuit timer is effective only as a multiple of the
line clock (the power line frequency):
o 16 2/3 ms per clock tick for 60 hertz
o 20 ms per clock tick for 50 hertz
/CONNECTIONS
/CONNECTIONS=option
Allows you to specify the type of connections permissable on the
local node. There are four options for CONNECTIONS:
INCOMING_ONLY Specifies that the local node permits incoming
connections only.
OUTGOING_ONLY Specifies that the local node permits outgoing
connections only. Specify this on systems
that can tolerate the overhead associated with
outgoing connections, such as standalone systems.
BOTH Specifies that the local node permit both
incoming and outgoing connections. Specify
this on systems that can tolerate the overhead
associated with outgoing connections, such as
standalone systems.
NONE Specifies that the local node disallow both
incoming and outgoing connections.
/CPU_RATING
/CPU_RATING=cpu-power
/NOCPU_RATING
The /CPU_RATING qualifier assigns your local VMS node a rating
that represents the power of your node's CPU (central processing
unit) relative to other CPUs in the LAN. The value of cpu-power
can range from 1 (for a CPU with the lowest power) to 100 (for a
CPU with the highest power).
The local node's LAT driver uses this value to calculate the
dynamic service rating for each service offered on the local
node. When a terminal server or VMS node requests a connection
to a service that is offered on the local node and one or more
other service nodes, the requesting node selects the service node
with the highest (most favorable) service rating. This selection
process is called load balancing.
Specify the /CPU_RATING qualifier to influence the service ratings
calculated for services on your node. If you specify a high value
for cpu_power, the LAT driver will calculate a relatively high
service rating for services on your node (service ratings as high
as 255 are possible). If you specify a low value, the LAT driver
will calculate relatively low service ratings; connections will
most likely be made to the same service that is offered on other
nodes. In either case, the LAT driver can calculate a greater
range of values for dynamic service ratings (the entire range from
(0 to 255). Consequently, the ratings will more accurately reflect
the availability of the service node.
By default, the LAT driver calculates a dynamic rating based on
the estimated CPU power of the local node. So, if you do not
modify the default by specifying the /CPU_RATING qualifier, or
if you specify the /NOCPU_RATING qualifier, services offered on
the local node will generally have lower ratings than services
offered on nodes having more powerful CPUs. Other factors involved
in the rating calculation, such as available memory and current
CPU usage, can further reduce the ratings for local services.
The following example illustrates one of the major benefits of
using the /CPU_RATING qualifier. If your local node has low
CPU power (relative to the range of CPU powers available with
VAX processors) but is the most powerful CPU that is usually
available, you can assign a high value to the /CPU_RATING
qualifier. Then, higher service ratings will be given to the
services offered on your node (as high as 255, the maximum value
for service ratings). For example, if your node is one of several
VAX 11/780s in a cluster which contains only VAX 11/750s and
VAX 11/780s, assign a high value to the /CPU_RATING qualifier.
Then the services offered on your node will have higher service
ratings.
If you do not specify the /CPU_RATING qualifier in the previous
example, the service ratings calculated for the VAX 11/780 will
tend to be low, far below the maximum possible value of 255.
/DEVICE_SEED
/DEVICE_SEED[=value]
The /DEVICE_SEED qualifier overrides the default lower boundary
for new LTA devices. The default is 0, and the maximum is 9999.
By default, if you do not specify a parameter to the LATCP CREATE
PORT command, LTA device unit numbers for LTA ports fall in the
following range (starting at the lower boundary):
( (MAX unit / 2) - 1 ) < n < ( MAX unit )
where:
o n is the device unit number of the LTA device (LTAn:).
o MAX unit is the maximum LTA device unit number. The default is
9999 (the absolute maximum). You can set this value using the
the /UNIT_NUMBER_MAXIMUM qualifier.
The channel numbers fall in this same range when ports are
created by assigning a channel to LTA0: with the $ASSIGN system
service.
/GROUPS
/GROUPS=option[,...]
Gives the listed groups access to services offered on your local
node or prevents the listed groups from accessing services offered
on your local node, depending on the options used.
A network manager organizes terminal server nodes into groups
based on the number of terminal server nodes in the LAT network.
Groups subdivide the LAT network, limiting the number of terminal
server nodes that can connect with a given VMS service node.
There can be as many as 256 groups, numbered 0 through 255.
By default all terminal server nodes and VMS nodes supporting
outgoing connections belong to group 0. If you enter one group
code, you can omit the parentheses. Use the SHOW NODE command for
a list of the groups enabled for your service node.
There are several options for the /GROUPS qualifier. For each
option described, there are two ways to specify more than one
group:
o List them separated by commas
o Specify a range
See Example 2 for the SET NODE command.
ENABLE=group-code[,...] Gives the listed groups access to your
service node.
DISABLE=group-code[,...] Prevents the listed groups from
accessing your service node. The listed
groups had been enabled previously for
access to your node.
ENABLE=group-code[,...], This option lets you enable certain
DISABLE=group-code[,...] groups and disable other groups in
one command line: gives access to
the groups listed with the ENABLE
option, and removes access from
the groups listed with the DISABLE
option. Enclose both ENABLE and
DISABLE in parentheses. For example,
/GROUP=(ENABLE=(10,12),DISABLE=(1-30)).
/IDENTIFICATION
/IDENTIFICATION[="identification-string"]
Describes and identifies a VMS node. Service nodes include the
identification string in service announcements. A VMS service
node announces its services at regular intervals established
with the SET NODE command. The LATCP SHOW NODE and server SHOW
NODE displays include this identification string. By default, the
identification string is the translation of SYS$ANNOUNCE.
An identification string can have up to 64 ASCII characters.
Enclose the string in quotation marks (").
/KEEPALIVE_TIMER
/KEEPALIVE_TIMER=secs
Allows you to control the maximum interval between idle run
messages sent by your local node to another service node to which
it has a LAT connection. The interval is in seconds. Your node
sends these messages when no other traffic is being generated
over the virtual circuit. If the service node acknowledges
these messages, your node will continue to monitor the status
of the circuit. If your node does not receive acknowledgement, it
responds as if the circuit is down.
Use this qualifier only if your node allows outgoing connections
(/CONNECTIONS=OUTGOING_ONLY or /CONNECTIONS=BOTH).
The default value is 20. Digital recommends this value for normal
Ethernet environments. For a heavily loaded Ethernet, consider
using a higher value. Set the timer in the range of 1 to 255. For
applications that require quick notification and possible failover
of a service node failure, use a lower value.
/LOG
/LOG
/NOLOG
Specifies whether LATCP displays a message confirming that the
node's characteristics were modified. The default is /NOLOG.
/MULTICAST_TIMER
/MULTICAST_TIMER=secs
Specifies the time, in seconds, between multicast messages sent
by a VMS service node. A multicast message announces the services
offered by a VMS service node. The minimum value is 10 seconds;
the maximum is 255 seconds. The default value is 60.
/NODE_LIMIT
/NODE_LIMIT=value
/NONODE_LIMIT
Specifies the maximum number of service nodes that your
local node can store in its service and node database. Use
this qualifier only if your node allows outgoing connections
(/CONNECTIONS=OUTGOING_ONLY or /CONNECTIONS=BOTH).
When the database reaches the node limit, no more nodes are added
to the database when your local node receives service announcement
messages. You can ensure that the node limit is not reached by
using the /USER_GROUPS qualifier to restrict access from the local
node to other service nodes on the network.
A value of 0 can also be used to mean no limit.
/RETRANSMIT_LIMIT
/RETRANSMIT_LIMIT=count
Specifies the number of times your local node repeats transmission
of a message to a service node after a transmission fails. If
the transmission is still unsuccessful after these attempts,
the virtual circuit between your local node and the service node
terminates, along with all sessions associated with the virtual
circuit.
Use this qualifier only if your node allows outgoing connections
(/CONNECTIONS=OUTGOING_ONLY or /CONNECTIONS=BOTH).
Specify a value in the range of 1 to 255. The default is 20. The
value you choose depends on the type of physical link used for
your network, as well as the amount of traffic on the network. See
your network manager for a suggested value.
/SERVICE_RESPONDER
/SERVICE_RESPONDER
/NOSERVICE_RESPONDER
Specifies whether your VMS system responds to special LAT
multicast messages that request service information. Some terminal
servers do not have their own service and node database. When a
user on such a terminal server requests a connection to a service,
the server sends a LAT multicast message requesting names of nodes
that offer the requested service. Service responder nodes reply
with the requested information.
If you specify /SERVICE_RESPONDER, your system responds to the
special LAT multicast messages. Only one or two nodes in the LAN
should be set up as service responder nodes. The nodes should have
the largest databases in the LAN. Use this option only if your
node allows outgoing connections (/CONNECTIONS=OUTGOING_ONLY or
/CONNECTIONS=BOTH).
If you specify /NOSERVICE_RESPONDER, your system does not respond
to the special LAT multicast messages. This is the default.
/SESSION_LIMIT
/SESSION_LIMIT=option
Specifies the maximum number of simultaneous sessions across
all local-access ports. This limit does not affect the use of
dedicated and application ports. It affects interactive port
creation only, limiting the amount of resources consumed by
interactive users creating new sessions.
There are several options for the /SESSION_LIMIT qualifier:
INCOMING=value Sets the session limit for incoming
connections only.
OUTGOING=value Sets the session limit for outgoing
connections only.
INCOMING=value,OUTGOING=valSets the limit for both outgoing and
incoming connections. Enclose this in
parentheses. For example, /SESSION_
LIMIT=(INCOMING=20, OUTGOING=25)
o A high limit allows users to have more sessions but increases
memory utilization on your local node.
o A low limit decreases memory utilization on your local node but
limits user access to services on the network.
If the limit is reached, interactive users cannot create new
sessions. In this case, you need to increase the session limit
or disconnect any connections that are no longer being used.
Specify a value in the range of 0 to 255. Specifying 0 leaves no
limit on the number of sessions that can be created. To prevent
sessions from being created, use the /CONNECTIONS qualifier.
/STATE
/STATE=option
Specifies whether LAT connections are allowed. There are three
options for STATE:
ON Starts the LAT port driver (and LAT protocol software).
OFF Stops the LAT port driver (and LAT protocol software) on
your node. Any existing LAT connections are aborted. Any
characteristics that you changed or set with LATCP are
lost.
To start the LAT protocol on your node again, invoke
LAT$SYSTARTUP.COM. The LAT characteristics defined in
LAT$SYSTARTUP.COM will take effect.
SHUT Specifies that new LAT connections cannot be created on
your local node, but existing connections may continue.
The LAT protocol continues running only until the last
active session disconnects. At that time, your node
changes to the OFF state.
/UNIT_NUMBER_MAXIMUM
/UNIT_NUMBER_MAXIMUM=value
Specifies the maximum unit number for a LAT device. For example,
if you specify 40, then LTA40: will be the device with the highest
unit number. Specify a value that is high enough to accommodate
all devices that may be in use simultaneously. When the number
of devices in use exceeds the value you specify, the system gives
certain LAT devices unit numbers that exceed your maximum.
/USER_GROUPS
/USER_GROUPS=option[,...]
Restricts access (from the local node) to service nodes in the
network that belong to the specified groups. Your local node can
access only those service nodes associated with the user groups
specified. The /USER_GROUPS qualifier also serves to limit the
number of nodes stored in your node's node database. (The local
node only stores information about the nodes and services that
belong to at least one of the specified user groups.) By default,
all LAT service nodes belong to group 0.
This qualifier affects your local node when outgoing connections
are enabled (/CONNECTIONS=OUTGOING_ONLY or /CONNECTIONS=BOTH).
Use the SHOW NODE command for a list of the user groups (service
groups) enabled for your node.
There are several options for the /USER_GROUPS qualifier. For each
option described here, there are two ways to specify more than one
group:
o List them separated by commas
o Specify a range.
ENABLE=group-code[,...] Gives your node access to the listed
user groups.
DISABLE=group-code[,...] Prevents your node from accessing the
listed groups. The listed groups were
enabled previously.
ENABLE=group-code[,...], This option lets you enable certain
DISABLE=group-code[,...] groups and disable other groups in one
command line: gives your node access
to the groups listed with the ENABLE
option, and prevents your node from
accessing the groups listed with the
DISABLE option. Enclose both ENABLE and
DISABLE in parentheses. For example,
/GROUP=(ENABLE=(10,12),DISABLE=(1-30)).
Examples
1. LATCP> SET NODE DUKE /IDENT="NODE DUKE, SALES VAXCLUSTER"
The SET NODE command in this example specifies node name DUKE
for your local VMS node. The identification string "NODE DUKE,
SALES VAXCLUSTER" is multicast from node DUKE.
2. LATCP> SET NODE /MULTICAST_TIMER=50 /GROUPS=(ENABLE=(1-3,8,11),
DISABLE=5)
The SET NODE command in this example causes your local node
to send multicast messages every 50 seconds to announce
DUKE's services to terminal servers. The command also enables
groups 1, 2, 3, 8, and 11 for access to the local node, and
it disables group 5 from accessing the local node. Group 5 had
been previously enabled.
3. LATCP> SET NODE /CONNECTIONS=BOTH /USER_GROUPS=(ENABLE=(24,121-127)
,DISABLE=0)
The SET NODE command in this example sets up your local node
to allow both incoming and outgoing connections. Users on your
local node can access those service nodes belonging to user
groups 24 and 121 through 127. Users cannot access service
nodes in user group 0.
4. LATCP> SET NODE /CIRCUIT_TIMER=80 /KEEPALIVE_TIMER=20 -
_LATCP> /RETRANSMIT_LIMIT=20 /CONNECTIONS=BOTH /MULTICAST_TIMER=60-
_LATCP> /GROUPS=(DISABLE=0,ENABLE=73) /SESSION_LIMIT=(OUTGOING=10,
INCOMING=0)
The SET NODE command in this example sets many characteristics
at once for node DUKE.
PORT
Logically associates a logical port on the local VMS node with
a remote port on a terminal server that supports a device.
Alternatively, it associates a logical port on the local VMS node
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
SET PORT port-name
Additional information available:
Parameter
port-name Specifies the name of the port. A port name must be in the form LTAn:, where n is a unique number from 1 through 9999.
Qualifiers
Additional information available:
/APPLICATION/DEDICATED/LOG/NODE/PORT
/QUEUED/SERVICE
/APPLICATION
Specifies that a port on the local VMS node is an application port, logically associated with a port on a terminal server or a dedicated port on another LAT service node. The terminal server port supports a device, for example, a printer. If the port is used to support a printer, the print queue is established in a startup command procedure. See the description of configuring remote printers on a terminal server in the Guide to Maintaining a VMS System. The port must have been created with the CREATE PORT command. The default port type is /APPLICATION.
/DEDICATED
Specifies that a logical port on your local VMS node is dedicated
to an application service. The /DEDICATED qualifier requires the
/SERVICE qualifier.
To set up an application service for a logical port on a LAT
service node:
1. Create the service (CREATE SERVICE/APPLICATION) and define the
dedicated port (CREATE PORT/DEDICATED). You can include these
commands in LAT$SYSTARTUP.COM.
2. Start the application program. Within the program, allocate
dedicated ports with the same name as those defined in
LAT$SYSTARTUP.COM.
/LOG
/LOG
/NOLOG
Specifies whether LATCP displays a message confirming that the
port's characteristics were modified. The default is /NOLOG.
/NODE
/NODE=remote-node-name
Specifies the name of a terminal server (or a remote VMS node that
supports outgoing connections) to be logically associated with the
specified application port on your VMS node. The server supports
a remote device. Note that you can set up an application port on
your local VMS node and associate the port with a dedicated port
on a remote LAT service node. The remote port is dedicated to an
application service.
/PORT
/PORT=remote-port-name
Specifies the name of the remote port on a terminal server that
supports a remote device, or specifies the name of a remote port
dedicated to a special service on a remote LAT service node. In
either case, the remote port is logically associated with the
specified application port on your local VMS node.
/QUEUED
/QUEUED
/NOQUEUED
Specifies queued or nonqueued access to the server port. The
default is /QUEUED.
A queued or nonqueued request is accepted by a terminal server if
a remote port is free. If the remote port is busy and queuing is
enabled on the terminal server, then the server queues the remote
request. If you do not want your remote requests to be queued on
the server, specify /NOQUEUED.
/SERVICE
/SERVICE=service-name
Specifies either of the following:
o The name of the remote service offered at a terminal server
port that will be associated with the specified application
port (/APPLICATION) on the local node
o A service name for an application program being offered on a
dedicated port (/DEDICATED) on a LAT service node
To specify the name of a remote service offered at a terminal
server port, use the /NODE and the /SERVICE qualifiers. To specify
a particular port for a service, use the /NODE, /PORT, and
/SERVICE qualifiers. Ask the terminal server manager for these
names.
To name a service for a particular application program to be
offered locally on a dedicated port, use the /DEDICATED and the
/SERVICE qualifiers. The service must have been created with the
CREATE SERVICE command. Assign only one service to a dedicated
port. Several ports can have the same service assigned.
Examples
1. LATCP> SET PORT LTA22: /APPLICATION /NODE=TS33EW /PORT=LN02
The SET PORT command in this example sets up port LTA22: as
an application port to be associated with the port named LN02
on the terminal server named TS33EW. This command associates
port LTA22: with a specific printer on the server. In the next
example, the SET PORT command associates a port with a set of
printers (designated by the service name PRINTER) on a terminal
server.
2. LATCP> SET PORT LTA19:/APPLICATION/NODE=TLAT1/SERVICE=PRINTER/QUEUED
The SET PORT command in this example shows how to associate
a local logical port with a service (several printers) on a
terminal server. The command associates the application port
LTA19: with the service PRINTER on terminal server TLAT1. The
service PRINTER can be associated with one or more ports on
TLAT1. The /QUEUED qualifier specifies that the server offering
the service PRINTER can queue the remote connection request if
all ports offering the service are in use. See the description
of print operations in the Guide to Maintaining a VMS System
for information on setting up print queues.
3. LATCP> SET PORT LTA21: /DEDICATED /SERVICE=GRAPHICS
The SET PORT command in this example specifies that the
application port LTA21: on the local VMS service node offers
the service GRAPHICS to users on terminal servers or on
VMS nodes that support outgoing connections. GRAPHICS is a
particular utility or application program.
4. LATCP> SET PORT MAIL_PORT /SERVICE=MAIL/NODE=BIGVMS
The SET PORT command in this example associates the port whose
logical name is MAIL_PORT with the dedicated service MAIL on
remote node BIGVMS. The port logically named MAIL_PORT was
created with the CREATE PORT command (see Example 3 in the
discussion of the CREATE PORT command). The logical port could
also have been created with a VMS DCL ASSIGN or DEFINE command.
On node BIGVMS, a port must be dedicated to the service MAIL by
using the SET PORT port-name /DEDICATED/SERVICE=MAIL command.
SERVICE
Dynamically changes the characteristics of a locally offered
service. You must have OPER privilege to use this command.
Format
SET SERVICE [service-name]
Additional information available:
Parameter
service-name Specifies the service whose characteristics are to be modified. If a service name is omitted, the default service name is the name of the local node you defined using the SET NODE command.
Qualifiers
Additional information available:
/APPLICATION/IDENTIFICATION/LOG/STATIC_RATING
/APPLICATION
Sets up the service as an application service. An application service offers a specific application on the service node rather than all of the resources on the service node. Define a dedicated port for the service, using the CREATE PORT and SET PORT commands.
/IDENTIFICATION
/IDENTIFICATION[="identification-string"]
Describes and identifies a VMS service. Service nodes include
the identification string in service announcements. A VMS service
node announces its services at regular intervals established with
the SET NODE command. The LATCP SHOW NODE and server SHOW NODE
displays include this identification string.
By default, the identification string is the translation of
SYS$ANNOUNCE. A VMS service node announces its services at regular
intervals established with the SET NODE command.
An identification string can have up to 64 ASCII characters.
Enclose the string in quotation marks.
/LOG
/LOG
/NOLOG
Specifies whether or not to display a message confirming that the
command was executed. The default is /NOLOG.
/STATIC_RATING
/STATIC_RATING=rating
/NOSTATIC_RATING
Enables or disables dynamic service ratings. The default is
/NOSTATIC_RATING. 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, the amount of memory, and the processor type. When
a terminal server or VMS 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.
When you use the /STATIC_RATING qualifier, you disable dynamic
service ratings so that you can specify a static rating. 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 your node less likely to be used; specify a high
value to make the node more likely to be used.
Example
LATCP> SET SERVICE SALES /IDENT="SALES FORCE TIMESHARING SERVICES"
The SET SERVICE command in this example specifies a new
identification string "SALES FORCE TIMESHARING SERVICES" for
the service SALES. This string is announced with the service
SALES in the multicast messages sent by a VMS service node.