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

 addr
    A pointer to a buffer containing the internet address where the
    remote program is located.
 prognum
    The program number associated with the remote procedure.
 versnum
    The version number associated with the remote procedure.
 wait
    The amount of time used between call retransmission if no
    response is received. Retransmission occurs until the ONC RPC
    calls time out.
 sockp
    A pointer to the socket number to be used for the remote
    procedure call. If sockp is RPC_ANYSOCK, then this routine opens
    a new socket and sets sockp.
 sendsize
    The size of the send buffer. If you specify 0, the routine
    chooses a suitable default.
 recvsize
    The size of the receive buffer. If you specify 0, the routine
    chooses a suitable default.