Routing messages

The following topics introduce the routing fields in the SNA-defined FM headers and describes how IMS uses these fields to route messages (and thus support distributed processing).

FM headers for message routing
ISC message routing information is provided within SNA-defined function management (FM) headers.
IMS use of routing parameters
IMS ISC without the Front-End Switch exit routine does not provide for automatic transaction routing when IMS is the front-end subsystem.
Routing examples
The following routing examples show typical functions that can be accomplished between two subsystems using ISC and how routing parameters are used to accomplish these functions.
Routing messages through MSC to an ISC LTERM
You can route messages across an MSC link to an ISC half session.

Parent topic: Accessing existing application programs with ISC