Sends a single message over a connection.

    The $ICC_TRANSMITW service completes synchronously; that is, it
    returns to the caller when the underlying transport layer has
    released use of the Transmit buffer. This does not mean that the
    data has been received by the partner application.

    For asynchronous completion, use the $ICC_TRANSMIT service.
    The $ICC_TRANSMIT service returns to the caller as soon as the
    transmission request has been queued to the transport layer,
    without waiting for notification that the transport layer has
    released control of the data buffer.

    On Alpha and Integrity server systems, this service accepts 64-
    bit addresses.

    Format

      SYS$ICC_TRANSMITW  conn_handle ,ios_icc ,[astadr] ,[astprm]

                         ,send_buf ,send_len

    C Prototype

      sys$icc_transmitw  (unsigned int conn_handle, struct _ios_icc

                         *ios_icc, void (*astadr)(__unknown_params),

                         __int64 astprm, char *send_buf, unsigned int

                         send_len);