A getclientid() call returns the identifier by which the calling application is known to the TCP/IP address space. Do not be confused by the term client in the name of this call; the call always returns the ID of the calling process, be it client or server. For example, in CICS® TCP/IP, this call is issued by the IBM® listener; the identifier returned in that case is that of the listener (a server). This identifier is used in the givesocket() and takesocket() calls.