(1) In programming, a statement that requests services from a subroutine or other program. The call is physically made to the subroutine by a branch instruction or some other linking method that is created by the assembler, compiler or interpreter. The routine that is called is responsible for returning control to the calling program after it has finished processing. See
stack.
(2) In a communications network, the action taken by the transmitting station to establish a connection with the receiving station.