By default, after a user issues a TRANSMIT command:

• TRANSMIT reads the data set to be transmitted, converts the records to a format suitable for transmission, and adds header information. It then routes the data to a punch output class B file that is directed to the receiving node and user ID. There the data is queued on the JES spool.
• The user to whom the data was sent issues a RECEIVE command, and sees a message that identifies the data set to be received. RECEIVE then prompts the user for information to use in restoring the data set.
• RECEIVE restores the data to its original format, and writes it to the data set indicated by the user. If an acknowledgment is requested, RECEIVE sends an acknowledgment to the person who issued the TRANSMIT command. If the security checker is active and the security labels of the sender and receiver are different, the installation can specify whether the acknowledgment is returned at the sender's or receiver's security label through the RECEIVE pre-acknowledgment notification exit INMRZ06R. The default is to use the sender's security label.

TRANSMIT, RECEIVE, and JES exits are given control at various points in the processing. You can use them to:

• Control who can use the TRANSMIT and RECEIVE commands
• Modify acknowledgment processing
• Enable users to transmit and receive data types other than those that TRANSMIT and RECEIVE support
• Control encryption and decryption processing
• Allocate NAMES and log data sets
• Reply to RECEIVE prompts
• Modify users' responses to RECEIVE prompts
• Record network use