This feature allows you to write UNIX applications to communicate with downstream legacy SNA PU type 2 systems, without requiring a mainframe. This allows you to completely eliminate the mainframe or to offload some of the mainframe processing on to less expensive UNIX systems.
SNAP-IX provides the subset of PU5 functions required to host the downstream PUs, while the Primary RUI Application Programming Interface allows you to write UNIX applications that communicate with downstream LU0 and LU2 applications.
A UNIX application uses SNAP-IX's Primary RUI API to communicate with a group of downstream PU2 systems, attached via SDLC, X.25 or LLC2 protocols.