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

    The client interface to the Portmapper service for a remote call
    and broadcast service. This routine allows a program to do a
    lookup and call in one step.
    Format
      #include  <rpc/pmap_clnt.h>
      enum clnt_stat  pmap_rmtcall(struct sockaddr_in *addr, u_long
                      prognum, u_long versnum, u_long procnum,
                      xdrproc_t inproc, char * in xdrproc_t outproc,
                      char * out, struct timeval timeout, u_long
                      *port );

1 - Arguments

 addr
    A pointer to a sockaddr_in structure containing the internet
    address of the host where the remote Portmapper resides.
 prognum
    The program number associated with the remote procedure.
 versnum
    The version number associated with the remote procedure.
 procnum
    The procedure number associated with the remote procedure.
 inproc
    The XDR routine used to encode the remote procedure's arguments.
 in
    A pointer to the remote procedure's arguments.
 outproc
    The XDR routine used to decode the remote procedure's results.
 out
    A pointer to the remote procedure's results.
 timeout
    A timeval structure describing the time allowed for the results
    to return to the client.
 port
    A pointer to a location for the returned port number. Modified
    to the remote program's port number if the pmap_rmtcall routine
    succeeds.

2 - Description

    A client interface to the Portmapper, which instructs the
    Portmapper on the host at the internet address *addr to make
    a call on your behalf to a procedure on that host. Use this
    procedure for a ping operation and nothing else. You can use
    the clnt_perrno routine to print any error message.

                                   NOTE
       If the requested procedure is not registered with the remote
       Portmapper, the remote Portmapper does not reply to the
       request. The call to pmap_rmtcall will eventually time out.
       The pmap_rmtcall does not perform authentication.

3 - Return Values

    enum clnt_stat     Returns the buffer containing the status of
                       the operation.