OSI/TS Configuration and Management Manual

Configuring the OSI/TS Subsystem

OSI/TS Configuration and Management Manual—424831-001

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TLAM SYSGEN Considerations

The maximum TPDU size to be used for Transport Layer connections over TLAM is

limited to the maximum I/O size supported by TLAM, as specified by the MAXIOSIZE

attribute the MAXIOSIZE default is 32000. Ordinarily, the OSI/TS subsystem

automatically determines each TLAM line’s maximum I/O size. However, you can

override the TLAM MAXIOSIZE value by doing one of the following:

•

Use the TSP^LANIOSIZE PARAM parameter to set the desired size when starting

the TSP process.

•

Alter the OSI/TS LANIOSIZE attribute of the PROCESS object.

Using TLAM with OSI/TS

TLAM is a system I/O process that provides local-area, connectionless-mode

subnetwork service over standard 802.3 and 802.4 networks. It has an application

interface and an interface to an intelligent controller that runs the data-link protocols

(logical link control and CSMA/CD).

Note that when you configure Layer 4 attributes to operate with TLAM processes, you

must specify the transport class 4 protocol.

TLAM Port Management

The following information describes how the OSI/TS subsystem names, creates, and

deletes TLAM ports.

Naming TLAM Subdevices

When interfacing with TLAM, the TSP process builds a TLAM port name by using the

first five characters after the $ sign of its own TSP process name as the prefix, followed

by a two-character alphanumeric string that is associated with the LSAP-selector it uses

(normally FE). This method allows for easy identification and prevents possible

duplicate names created by other TSP processes.

Creating TLAM Ports

The first time a connect request or an attach request is received requiring the TLAM

device specified in the NSPDEVICE attribute, the TSP process adds the following:

•

A normal port to the TLAM subdevice

•

A port to receive broadcast messages, if the ESISENABLE attribute is set to ON

While the naming scheme for TLAM ports guarantees that no two TSP processes can

create ports with identical names, the TLAM subsystem can still potentially reject a port

at this stage. This can happen when the LSAP selector (which is an attribute of the

ports) used by the current TSP process is the same as that used by other TSP processes

that are stopped. In such cases, an event message is generated to point to the source of

the problem.

To avoid this problem, always do the following: