qRFC communication consists of nothing more than tRFC communication with a preceding inbound queue and outbound queue. tRFC communication is typically constructed as follows:
tRFC Communication
REPORT rstrfct0. ... CALL FUNCTION 'rfc_function' DESTINATION rfcdest IN BACKGROUND TASK ( AS SEPARATE UNIT ) EXPORTING ... TABLES ... ... COMMIT WORK.
All data that belongs to a tRFC call (CALL FUNCTION... IN BACKGROUND TASK) in an LUW is saved to two internal tables with a transaction ID (TID).
At COMMIT WORK time, the contents of these internal tables to the database (ARFCSSTATE and ARFCSDATA). The RFC Manager then requires a DIALOG work process to send this LUW to the partner system.
More Information
You can find detailed information about qRFC design in:
qRFC Variants
Using qRFC with the RFC Library