APPC/MVS is an SNA application that extends APPC support to the z/OS operating system. APPC/MVS provides full LU 6.2 capacity to z/OS applications to allow communication with other applications across a distributed SNA network.
APPC/MVS provides programming support by providing an API based on the CPI-C interface. This interface is implemented in a lower-level API that is z/OS-specific:
CPI-C calls all begin with CM. For example, CMALLC (Allocate).
z/OS calls all begin with ATB. For example, ATBSEND (Send_data).
The CPI-C calls are portable to non-z/OS platforms. ATB calls are not portable to non-z/OS platforms.
