# Erlang -- megaco_tcp

# megaco_tcp

###
Module

megaco_tcp

###
Module Summary

Interface module to TPKT transport protocol for Megaco/H.248.

###
Description

This module contains the public interface to the TPKT (TCP/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 TCP/IP transport service. Use exit(TransportRef, Reason) to stop the transport service.

####
listen(TransportRef, ListenPortSpecList) -> ok

### Types

TransportRef = pid() | regname()
OptionListPerPort = [Option]
Option = {port, integer()} | {options, list()} | {receive_handle, term()} | {inet_backend, default | inet | socket}

This function is used for starting new TPKT listening socket for TCP/IP. The option list contains the socket definitions.

inet_backend

  Choose the inet-backend.

  This option make it possible to use a different inet-backend ('default', 'inet' or 'socket').

  Default is default (system default).

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

### Types

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

This function is used to open a TPKT connection.

module

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

  small

    receive_message

  large

    process_received_message

  Default value is megaco.

inet_backend

  Choose the inet-backend.

  This option make it possible to use a different inet-backend ('default', 'inet' or 'socket').

  Default is default (system default).

####
close(Handle) -> ok

### Types

Handle = socket_handle()

This function is used for closing an active TPKT connection.

####
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.

####
send_message(Handle, Message) -> ok

### Types

Handle = socket_handle()
Message = binary() | iolist()

Sends a message on a connection.

####
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) -> ok

### Types

ControlPid = pid()

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

Retreive the TCP related (SNMP) statistics counters.

####
reset_stats() -> void()

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

### Types

SendHandle = send_handle()

Reset all TCP related (SNMP) statistics counters.