With UPIC as the carrier system you can link CPI-C applications which run on your local system with UTM applications which run on Unix, Linux or Windows systems or BS2000 systems. The UTM service requested by the client can use either the CPI-C or the KDCS interface of openUTM.
This chapter describes:
the general structure of CPI-C client programs
the exchange of messages between client and server
conversion of the exchanged data in heterogeneous links
programming notes for communication with UTM single-step and multi-step services
the encryption procedures
programming client programs that are linked to several services in parallel (multiple conversations). Multiple conversations are only possible if the client is running on a system that supports multithreading.
the security functions of openUTM, which can be used when UPIC client programs are connected.
the CPI-C functions supported by the UPIC carrier system. The individual CPI-C function calls are described in full (the CPI-C Specification of X/Open is therefore not necessary).
First, however, we will explain some CPI-C terms which are used in the following chapters.