gtps2m0dACF/SNA Data Communications Reference

TPF Outbound Message Flow

Figure 2 shows TPF's outbound message flow for ALC and SNA terminals. See the TPF Data Communications Services Reference for additional information on message routing and message flow.

Figure 2. TPF Outbound Message Flow


The output message processing starts when the application issues a ROUTC macro. The operands of the ROUTC macro require the user to supply a routing control parameter list (RCPL) and a message block. The RCPL contains the origin and destination of the message, and the message block contains the data stream as it should be sent to the destination. The ROUTC macro code performs the following:

The message is queued on DASD before transmission if:

Queued messages are sent when the transmission media is available. These additional functions are provided for destinations that require queuing the message: