Remote LTERMs

A remote LTERM is a logical terminal that does not reside on the local system.

Recommendation: In remote IMS systems, define the input LTERM from the local IMS system as a remote LTERM only to send message switches, remote broadcasts, or messages from an application program to an alternate remote terminal (alternate PCB). In other cases, IMS remembers the input LTERM and can return response messages from remote systems to the input LTERM without the input LTERM being defined in the remote system.

You can define remote LTERMs by using ETO MSC descriptors. The ETO MSC descriptor relates remote LTERMs to statically defined MSC links.

You can also define remote LTERMs dynamically by using the type-2 CREATE LTERM command.

To help return response messages to the input (source or origin) LTERM, IMS carries the source LTERM name and SYSID in the remote message. To send a response message to an LTERM other than the source LTERM, you must define a remote LTERM.

If you use the NAME macro, in the remote system, define NAME macros that have the name of the local terminal in the local system. Associate the NAME macro with the MSNAME that defines the destination SYSID of the local system.
If you use the CREATE LTERM command to dynamically create the remote LTERM in the remote system, define the remote LTERM name with the same name as the local terminal in the local system. Associate the remote LTERM with the logical link path (MSNAME) that defines the destination SYSID of the local system.

For example, in the following figure, IMS A has local LTERMA, IMS B has local LTERMB, and IMS D has local LTERMD. IMS B can send message switches and remote broadcasts from LTERMB to LTERMD because LTERMD is defined remotely in IMS B. LTERMD is not actually defined with SYSID=(5,2), but it assumes those SYSIDs when the message is issued. LTERMD is associated with MSNAME BAD, which is defined with SYSID=(5,2) in IMS B. This association is established by placing the NAME macro for LTERMD after the following MSNAME macro:

BAD MSNAME SYSID=(5,2)
        NAME LTERMD

This naming differs from remote transaction definitions, which are explicitly defined with remote and local SYSIDs.

Also, LTERMA in IMS A can send message switches or remote broadcasts to LTERMD in IMS D. Similarly, LTERMD in IMS D can send message switches or remote broadcasts to LTERMA in IMS A. Both IMS A and IMS D have remote LTERM specifications for the other system's local LTERM.

TRAND in IMS D can send alternate messages to LTERMB in IMS B or to LTERMA in IMS A. MSNAMEs are defined with names for the purpose of:

Displaying the queue counts for the named logical link path
Stopping the sending of all messages from a terminal except those continuing a conversation
Starting the logical link path
Purging the logical link path in an MSC network for which input is stopped
Allowing application programs to use directed routing
Reassigning them to different links by using either the type-1 command /MSASSIGN MSNAME msname LINK link# or the type-2 command UPDATE MSNAME NAME(msname) SET(MSLINK(linkname))

In the following figure, the name of each MSNAME is the two-character name preceding MSNAME.

Begin figure description: This figure was described in the preceding text. End description.