SilcStream silc_socket_udp_stream_create(SilcSocket sock,
                                             SilcBool ipv6,
                                             SilcBool connected,
                                             SilcSchedule schedule);

    Creates UDP socket stream of the UDP connection indicated by `sock'.
    The stream can be destroyed by calling the silc_stream_destroy.
    The `connected' defines whether the socket is in connected or in
    connectionless state.

    Note that, UDP packets may be read only through the notifier
    callback (see silc_stream_set_notifier), when SILC_STREAM_CAN_READ
    is returned to the callback.  Because of this the notifier callback
    must be set.

    Note that, UDP packet sending using silc_stream_write and receiving
    with silc_stream_read works only if the `sock' is a UDP socket in a
    connected state.  In connectionless state sending packets with
    silc_stream_write is possible only if the remote address and port
    has been set with silc_socket_stream_set_info.  If it is not set
    in connectionless state packets may be sent only by using the
    silc_net_udp_send function.  In connectionless state packets may be
    received only by using silc_net_udp_receive.

    This function returns the created SilcStream or NULL on error.

    If the silc_stream_set_notifier is called the stream is set to
    non-blocking mode.