# megaco_udp

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Module

megaco_udp

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Module Summary

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.

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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.

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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.

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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.

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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.

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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}

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

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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.

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reset_stats() -> void()

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reset_stats(SendHandle) -> void()

### Types

SendHandle = send_handle()

Reset all TCP related (SNMP) statistics counters.