A method for application programs to communicate on a local system, or between a local system and a remote system using the intersystem communications function (ICF). Examples of these communications methods include (a) asynchronous communications, (b) binary synchronous communications (BSC), (c) intrasystem communications, or (d) Systems Network Architecture (SNA), such as advanced program-to-program communications (APPC) and SNA upline facility (SNUF).