This means no new applications and commands need to be learned for network operation. This feature is the most flexible and powerful one that any network software package can provide. It basically allows an applications programmer to split up a program, so that different pieces of the program execute on different machines a network. If the two programs happen to end up on the same machine, the IPCF mechanism still works. The User does not need to understand the detailed mechanisms of communications software in order to communicate.
Calls are device-independent.
Programs on one system can concurrently communicate with programs on other systems using a single communications controller. A single program can establish multiple virtual circuits to other programs in the network. Terminal traffic between two systems is multiplexed over the same physical facilities as inter-program data, so no additional hardware is needed to share terminals between systems. This feature is ordinarily invisible to user programs, which cannot distinguish data entering via a packet network from data coming in over AMLC lines. A variant of the IPCF facility allows users to include the terminal handling protocol code in their own virtual space, thus enabling them to control multiple terminals on the packet network within one program.