NAME

       megaco_udp - Interface module to UDP transport protocol for Megaco/H.248.

DESCRIPTION

       This  module  contains  the  public interface to the UDP/IP version transport protocol for
       Megaco/H.248.

EXPORTS

       start_transport() -> {ok, TransportRef}

              Types:

                 TransportRef = pid()

              This  function  is  used  for  starting   the   UDP/IP   transport   service.   Use
              exit(TransportRef, Reason) to stop the transport service.

       open(TransportRef, OptionList) -> {ok, Handle, ControlPid} | {error, Reason}

              Types:

                 TransportRef = pid() | regname()
                 OptionList = [option()]
                 option()   =   {port,   integer()}   |   {options,  list()}  |  {receive_handle,
                 receive_handle()} | {module, atom()} | {inet_backend, default | inet | socket}
                 Handle = socket_handle()
                 receive_handle() = term()
                 ControlPid = pid()
                 Reason = term()

              This function is used to open an UDP/IP socket.

                module:
                  The option makes it possible for the user to provide their own callback module.
                  The functions receive_message/4 or process_received_message/4 of this module is
                  called when a new message is received. Which one depends on  the  size  of  the
                  message:

                  small:
                    receive_message

                  large:
                    process_received_message

                  Default value is megaco.

       close(Handle, Msg) -> ok

              Types:

                 Handle = socket_handle()
                 Msg

              This function is used for closing an active UDP socket.

       socket(Handle) -> Socket

              Types:

                 Handle = socket_handle()
                 Socket = inet_socket()

              This   function   is   used  to  convert  a  socket_handle()  to  a  inet_socket().
              inet_socket() is a plain socket, see the inet module for more info.

       create_send_handle(Handle, Host, Port) -> send_handle()

              Types:

                 Handle = socket_handle()
                 Host = {A,B,C,D} | string()
                 Port = integer()

              Creates a send handle from a transport handle. The send handle is  intended  to  be
              used by megaco_udp:send_message/2.

       send_message(SendHandle, Msg) -> ok

              Types:

                 SendHandle = send_handle()
                 Message = binary() | iolist()

              Sends    a    message   on   a   socket.   The   send   handle   is   obtained   by
              megaco_udp:create_send_handle/3. Increments  the  NumOutMessages  and  NumOutOctets
              counters  if message successfully sent. In case of a failure to send, the NumErrors
              counter is not incremented. This is done elsewhere in the megaco app.

       block(Handle) -> ok

              Types:

                 Handle = socket_handle()

              Stop receiving incoming messages on the socket.

       unblock(Handle) -> ok

              Types:

                 Handle = socket_handle()

              Starting to receive incoming messages from the socket again.

       upgrade_receive_handle(ControlPid, NewHandle) -> ok

              Types:

                 ControlPid = pid()
                 NewHandle = receive_handle()
                 receive_handle() = term()

              Update the receive handle  of  the  control  process  (e.g.  after  having  changed
              protocol version).

       get_stats() -> {ok, TotalStats} | {error, Reason}
       get_stats(SendHandle) -> {ok, SendHandleStats} | {error, Reason}
       get_stats(SendHandle, Counter) -> {ok, CounterStats} | {error, Reason}

              Types:

                 TotalStats = [total_stats()]
                 total_stats() = {send_handle(), [stats()]}
                 SendHandle = send_handle()
                 SendHandleStats = [stats()]
                 Counter = udp_stats_counter()
                 CounterStats = integer()
                 stats() = {udp_stats_counter(), integer()}
                 tcp_stats_counter()  =  medGwyGatewayNumInMessages  | medGwyGatewayNumInOctets |
                 medGwyGatewayNumOutMessages | medGwyGatewayNumOutOctets | medGwyGatewayNumErrors
                 Reason = term()

              Retreive the UDP related (SNMP) statistics counters.

       reset_stats() -> void()
       reset_stats(SendHandle) -> void()

              Types:

                 SendHandle = send_handle()

              Reset all TCP related (SNMP) statistics counters.