DECnet-Plus
Network Control Language Reference

The Routing module provides a Connectionless-mode Network Service (CLNS); for more information, refer to the Routing chapter.

The X.25 Access module, if configured into the system, provides a reliable Connection-Oriented Network Service (CONS); for more information, refer to the X.25 Access chapter.

For RFC 1006 and RFC 1859 on OpenVMS, this feature requires an installed TCP/IP product that supports the PATHWORKS Internet Protocol (PWIP) interface.

For Digital UNIX, any attributes that are specific to CONS will only be accessible if X.25/CONS has been installed and configured into the system. See Section 20.1.4 for more information. The Connectionless Transport Service, known as CLTS or CLTP, allows for the transfer of data between correspondent transport service users on a connectionless basis. The service provides for single-access data transfer for corresponding transport service users, without the overhead of establishing a connection. This protocol benefits those applications that require a one-time, one-way transfer of data toward one transport service user. CLTS runs over CLNS.

Table 20-2 shows the relationship between the transport protocols and the network services.

Table 20-2 Transport Protocols and Network Services
Port Attributes Class 4 (COTS) over CLNS Class 4 (COTS) over CONS Class 2 (COTS) over CONS Class 0 (COTS) over CONS CLTS over CLNS¹ RFC 1006² RFC 1859²

acknowledgment delay time * *

checksums * *

client * * * * * *

CONS template * * *

cr timeout * * * *

direction * * * * * *

er timeout * * * *

expedited data * * * *

extended format * * *

inactivity time * *

initial retransmit time * *

keepalive time * *

local DTE address * * *

local nsap * * * * *

local reference * * * * * *

local RFC 1006 IP address * *

local RFC 1006 port number * *

local transport selector * * * * * * *

maximum nsdu size * * * * *

name * * * * * * *

negotiable classes¹ * * * *

negotiated tpdu size * * * * * *

network port * * * *

network service * * * * * * *

protocol class * * * * * *

remote DTE addres * * *

remote identifier * * * *

remote nsap * * * *

remote reference * * * * * *

remote RFC 1006 IP address * *

remote RFC 1006 port number * *

remote transport selector * * * * * *

request acknowledgment * *

retransmit threshold * *

roundtrip delay estimate * *

type * * * * * * *

uid * * * * * * *

use CLNS error reports *

Template Attributes

acknowledgment delay time * *

checksums * *

classes * * * *

CONS template * * *

cr timeout * * * *

er timeout * * * *

expedited data * * * * *

inbound * * * * * * *

initial retransmit time * * * *

keepalive time * *

local nsap * * * * *

maximum nsdu size * * * * *

name * * * * * * *

network service * * * * * * *

retransmit threshold * *

RFC 1006 port number * *

security * * * *

use CLNS error reports *

**Table 20-2 Transport Protocols and Network Services**
Port Attributes	Class 4 (COTS) over CLNS	Class 4 (COTS) over CONS	Class 2 (COTS) over CONS	Class 0 (COTS) over CONS	CLTS over CLNS¹	RFC 1006²	RFC 1859²
acknowledgment delay time	*	*
checksums	*	*
client	*	*	*	*		*	*
CONS template		*	*	*
cr timeout			*	*		*	*
direction	*	*	*	*		*	*
er timeout			*	*		*	*
expedited data	*	*	*				*
extended format	*	*	*
inactivity time	*	*
initial retransmit time	*	*
keepalive time	*	*
local DTE address		*	*	*
local nsap	*	*	*	*	*
local reference	*	*	*	*		*	*
local RFC 1006 IP address						*	*
local RFC 1006 port number						*	*
local transport selector	*	*	*	*	*	*	*
maximum nsdu size		*	*	*		*	*
name	*	*	*	*	*	*	*
negotiable classes¹	*	*	*	*
negotiated tpdu size	*	*	*	*		*	*
network port	*				*	*	*
network service	*	*	*	*	*	*	*
protocol class	*	*	*	*		*	*
remote DTE addres		*	*	*
remote identifier	*	*	*				*
remote nsap	*	*	*	*
remote reference	*	*	*	*		*	*
remote RFC 1006 IP address						*	*
remote RFC 1006 port number						*	*
remote transport selector	*	*	*	*		*	*
request acknowledgment	*	*
retransmit threshold	*	*
roundtrip delay estimate	*	*
type	*	*	*	*	*	*	*
uid	*	*	*	*	*	*	*
use CLNS error reports	*
Template Attributes
acknowledgment delay time	*	*
checksums	*	*
classes	*	*	*	*
CONS template		*	*	*
cr timeout			*	*		*	*
er timeout			*	*		*	*
expedited data	*	*	*			*	*
inbound	*	*	*	*	*	*	*
initial retransmit time	*	*	*	*
keepalive time	*	*
local nsap	*	*	*	*	*
maximum nsdu size		*	*	*		*	*
name	*	*	*	*	*	*	*
network service	*	*	*	*	*	*	*
retransmit threshold	*	*
RFC 1006 port number						*	*
security	*	*	*	*
use CLNS error reports	*

¹Digital UNIX
²OpenVMS

20.1 osi transport

The osi transport entity is the top-level entity in the hierarchy of entities belonging to the OSI transport module.
add [node node-id] osi transport {nsap addresses [set] | cons filters [set] | RFC1006 listener ports [set] (OpenVMS) }
create [node node-id] osi transport
delete [node node-id] osi transport
disable [node node-id] osi transport
enable [node node-id] osi transport
enable [node node-id] osi transport [cons filters [set] (Digital UNIX)
remove [node node-id] osi transport {cons nsap addresses [set] | cons filters [set] | RFC1006 listener ports [set] (OpenVMS) }
set [node node-id] osi transport {cltp nsap selector integer (Digital UNIX) | congestion avoidance boolean | CONS filters [set] | CONS nsap address [set] | delay factor integer | delay weight integer | disconnect holdback seconds | maximum cltp ports integer (Digital UNIX) | maximum listeners integer (Digital UNIX) | maximum multiplexing integer | maximum network connections integer | maximum receive buffers integer (OpenVMS) | maximum remote nsaps integer | maximum transport connections integer | maximum window integer | nsap selector integer | RFC1006 listener ports [set] (OpenVMS) }
show [node node-id] osi transport [all [attributes] | all characteristics | all status ]

20.1.1 Characteristic Attributes

CLNS classes supported

Default: Class {4} Value: Bit-set

Set of protocol classes supported on the Connectionless Network Service (CLNS). You cannot modify this characteristic.
cltp nsap selector (Digital UNIX)

Default: 0 Value: 0--255 (except 32)

The NSAP selector to use for CLTS when running over CLNS. If the value is 0 or 1, a single NSAP is shared between the Connection-Oriented Transport Service (COTS), and the connectionless transport protocol according to the osi transport attribute nsap selector. If both nsap selectors are 0 or 1, then COTS and CLTS over CLNS are disabled.
This attribute cannot be set either to 32, which is the value of the NSP NSAP selector, or to the current setting of the osi transport attribute, nsap selector, if the attribute has a value other than 0 or 1.
This attribute cannot be modified when transport is enabled.
congestion avoidance

Default: True Value: True or false

Enables the use of the automatic congestion avoidance mechanism to reduce the transport window size in response to an indication from the Network layer when operating on the Connectionless Network Service (CLNS).
CONS classes supported

Default: Classes {0, 2, 4} Value: Bit-set

Set of protocol classes supported on the Connection-Oriented Network Service (CONS). You cannot modify this characteristic. See Section 20.1.4 for more information.
CONS filters

Default: { } Value: Set of simple names

The names of X.25 Access module filters used to determine which inbound network connection requests should be directed to the transport entity. You can modify this characteristic only when the entity is disabled.
For each cons filter, there must be a corresponding x25 access template with the same name. One or more of these filters must be specified in order to run COTS over CONS. The X.25 access filter osi transport is typically used. See Section 20.1.4 for more information.
CONS nsap addresses

Default: { } Value: Set of NSAP addresses

The set of valid NSAP addresses for use with CONS. One or more NSAPs must be specified to run COTS over CONS. See the DECnet-Plus Planning Guide for more information.
delay factor

Default: 4 Value: 2--15

Factor by which to multiply the current value of the round-trip delay estimate status attribute in order to set a value for the retransmission timer. This attribute works with protocol class 4 only.
delay weight

Default: 5 Value: 0--255

Relative weighting to apply to the current estimate and to a new sample when estimating round-trip delay. This attribute works with protocol class 4 only.
disconnect holdback

Default: 0 Value for Digital UNIX: 0-- (2 ^ ³¹ - 1 )

Default: 0 Value for OpenVMS: 0-- (2 ^ ³² - 1 )

When operating over the Connection-Oriented Network Service (CONS), the length of the time to maintain a network connection for possible reuse after all transport connections multiplexed upon it have been disconnected. Specified in seconds. This characteristic may not be changed while the transport entity is enabled. See Section 20.1.4 for more information.
iso version

Default: None Value: 1

Version number of ISO 8073 to which the implementation conforms. You cannot modify this characteristic.
maximum cltp ports (Digital UNIX)

Default: 128 Value: 0-- (2^ ³² -1)

Maximum number of CLTS ports at one time. This characteristic can be increased only while transport is enabled. You can modify this characteristic to a lower value only when the entity is disabled.
maximum listeners (Digital UNIX)

Default: 32 Value: 1--65535

Maximum number of listeners at one time. This characteristic can be increased only while transport is enabled. You can modify this characteristic to a lower value only when the entity is disabled.
maximum multiplexing

Default for Digital UNIX: 1023 Value: 1--1023

Default for OpenVMS: (2 ^ ³² - 1 ) Value: 1-- (2 ^ ³² - 1 )

When operating over the Connection-Oriented Network Service (CONS), the maximum number of transport connections that can be multiplexed on any single network connection. This characteristic can be increased only when the transport entity is enabled. You can modify this characteristic to a lower value only when the entity is disabled. See Section 20.1.4 for more information.
maximum network connections

Default for Digital UNIX: 1023 Value: 0--1023

Default for OpenVMS: (2 ^ ³² - 1) Value: 0-- (2 ^ ³² - 1)

When operating over the Connection-Oriented Network Service (CONS), the maximum number of network connections that can be in use concurrently by DNA OSI transport. This characteristic can be increased only when the transport entity is enabled. See Section 20.1.4 for more information.
maximum receive buffers (OpenVMS)

Default: 2000 Value: 1-- (2 ^ ³² - 1)

Maximum number of receive buffers that can store received DT transport PDUs. You can modify this characteristic only when the entity is disabled. Also, you can only increase the characteristic value.
maximum remote nsaps

Default for Digital UNIX: 160 Value: 1-65536

Default for OpenVMS: 201 Value: 0-- (2^ ³² -1)

Maximum number of remote NSAPs that can exist concurrently. This value must be greater than the current value of maximum transport connections. You can modify this characteristic to a lower value only when the entity is disabled. This characteristic can be increased when enabled.
maximum transport connections

Default for Digital UNIX: 128 Value: 0--1023

Default for OpenVMS: 200 Value: 0-- (2^ ³² -1)

Maximum number of active transport connections allowed at one time. Must be less than the current value of maximum remote nsaps. You can modify this characteristic to a lower value only when the entity is disabled.
maximum window

Default for Digital UNIX: 20 Value: 1--65535

Default for OpenVMS: 8 Value: 1--65535

Maximum credit window that can be granted on a transport connection. This is used for control of the number of data segments (PDUs) allowed to be transmitted over a particular transport connection before at least one acknowledgment must be returned from the destination system. If the number of PDUs already transmitted equals the maximum window and no corresponding acknowledgments have been received, transport stops sending PDUs over the transport connection and waits for an acknowledgment message. You can modify this characteristic to a lower value only when the entity is disabled.
nsap selector

Default: 33 Value: 0--255 (except 32)

The NSAP selector to use for the Connection-Oriented Transport Service (COTS) when running over CLNS. If 0 or 1, COTS over CLNS is not enabled. This attribute cannot be set to 32, which is the value of the NSP NSAP selector. Or, on Digital UNIX, to the current setting of the osi transport attribute cltp nsap selector if it is other than 0 or 1.
This attribute cannot be modified when transport is enabled.
RFC 1006 listener ports (OpenVMS)

Default: { 102, 399 } Value: Set of TCP/IP port numbers

The names of the TCP listener ports used to receive inbound RFC 1006 connection requests. Port 102 is applicable for RFC 1006 (OSI over TCP/IP) connections, and port 399 is applicable for RFC 1859 (DECnet over TCP/IP) connections. You can only remove RFC 1006 listener ports when the entity is disabled.
support map

Default: None Value: False

Specifies whether the implementation supports the MAP (Manufacturing Automation Protocol) entity. You cannot modify this characteristic.
version

Default: None Value: V1.1.0

Version number of the DNA OSI transport architecture specification to which the implementation conforms. You cannot modify this characteristic.

20.1.2 Status Attributes

currently active cltp ports (Digital UNIX)
Number of active CLTS ports.
currently active connections
Number of active transport connections.
currently active listeners (Digital UNIX)
Number of active listeners. The Session Control listener (local transport selector 'DEC0'H) can exist even when osi transport is disabled. All other listeners are deactivated when transport is disabled.
state
Status of the osi transport entity.

off The osi transport entity is disabled.

on The osi transport entity is enabled.

uid
Entity's unique identifier, which is generated when the entity is created.

20.1.3 Exception Messages

For create:

already exists
An osi transport entity already exists.
For delete:
wrong state
Disable the osi transport entity before trying to delete it.
For enable:
CONS filters unavailable
Attempt to enable the OSI transport module failed because the X.25 access filters, specified by the cons filters attribute, either do not exist or are already in use.
OSI transport disabled (Digital UNIX)
Cannot enable a set of cons filters unless OSI transport has already been enabled.
routing unavailable
Attempt to enable the OSI transport module failed because the port to routing (CLNS) could not be opened.

20.1.4 X.25/CONS Configuration

Certain transport attributes apply only when X.25 is installed and configured in the system. These attributes are indicated by references in each attribute description.

To use osi transport over X.25:

Set the osi transport entity attribute cons filters. Verify that an X.25 access filter with the same name exists.
Set the osi transport entity attribute cons nsap addresses.
Create one or more OSI transport templates for use over CONS.
In the new OSI transport template, set the inbound characteristic to true.
In the new OSI transport template, set the network service to cons or any (allowed for incoming connections only).
In the new OSI transport template, check the cons template. Verify that an X.25 access template with the same name exists.
To write a program that uses OSI transport over CONS, see the DECnet-Plus Planning Guide.

20.1.5 RFC 1006 and RFC 1859 Configuration (OpenVMS)

Certain transport attributes only apply when operating over TCP/IP and are indicated by references in each attribute description. To use RFC 1006 and/or RFC 1859:

Set the OSI transport entity attribute RFC 1006 listener ports to 102 (for RFC 1006) and 399 (for RFC 1859). Verify that the installed TCP/IP provider has TCP port 102 and 399 bound.
Create one or more OSI transport templates for use over RFC 1006.
In the new OSI transport template, set the network service to RFC 1006 and the inbound characteristic to true.

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Default: 0	Value for Digital UNIX: 0-- (2 ^ ³¹ - 1 )
Default: 0	Value for OpenVMS: 0-- (2 ^ ³² - 1 )

Default for Digital UNIX: 1023	Value: 1--1023
Default for OpenVMS: (2 ^ ³² - 1 )	Value: 1-- (2 ^ ³² - 1 )

Default for Digital UNIX: 1023	Value: 0--1023
Default for OpenVMS: (2 ^ ³² - 1)	Value: 0-- (2 ^ ³² - 1)

Default for Digital UNIX: 160	Value: 1-65536
Default for OpenVMS: 201	Value: 0-- (2^ ³² -1)

Default for Digital UNIX: 128	Value: 0--1023
Default for OpenVMS: 200	Value: 0-- (2^ ³² -1)

Default for Digital UNIX: 20	Value: 1--65535
Default for OpenVMS: 8	Value: 1--65535

off	The osi transport entity is disabled.
on	The osi transport entity is enabled.

DECnet-PlusNetwork Control Language Reference

20.1 osi transport

20.1.1 Characteristic Attributes

CLNS classes supported

cltp nsap selector (Digital UNIX)

congestion avoidance

CONS classes supported

CONS filters

CONS nsap addresses

delay factor

delay weight

disconnect holdback

iso version

maximum cltp ports (Digital UNIX)

maximum listeners (Digital UNIX)

maximum multiplexing

maximum network connections

maximum receive buffers (OpenVMS)

maximum remote nsaps

maximum transport connections

maximum window

nsap selector

RFC 1006 listener ports (OpenVMS)

support map

version

20.1.2 Status Attributes

currently active cltp ports (Digital UNIX)

currently active connections

currently active listeners (Digital UNIX)

state

uid

20.1.3 Exception Messages

already exists

wrong state

CONS filters unavailable

OSI transport disabled (Digital UNIX)

routing unavailable

20.1.4 X.25/CONS Configuration

20.1.5 RFC 1006 and RFC 1859 Configuration (OpenVMS)

DECnet-Plus
Network Control Language Reference