VMS Help TCPIP Services, Programming Interfaces, RPC Client Routines, clnt_control, Description  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    For UDP and TCP transports specify any of the following for code:

    CLSET_TIMEOUT      struct         Set total timeout
                       timeval
    CLGET_TIMEOUT      struct         Get total timeout
                       timeval
    CLGET_SERVER_ADDR  struct         Get server address
                       sockaddr_
                       in
    CLGET_FD           int            Get associated socket
    CL_FD_CLOSE        void           Close socket on clnt_destroy
    CL_FD_NCLOSE       void           Leave socket open on clnt_
                                      destroy

    If you set the timeout using clnt_control, ONC RPC ignores the
    timeout parameter in all future clnt_call calls. The default
    total timeout is 25 seconds.

    For the UDP transport two additional options are available:

    CLSET_RETRY_       struct         Set retry timeout
    TIMEOUT            timeval
    CLGET_RETRY_       struct         Get retry timeout
    TIMEOUT            timeval

    The timeout value in these two calls is the time that UDP waits
    for a response before retransmitting the message to the server.
    The default time is 5 seconds. The retry timeout controls when
    UDP retransmits the request, the total timeout controls the total
    time that the client should wait for a response. For example,
    with the default settings, UDP will retry the transmission four
    times at 5-second intervals.