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Introduction

Håkan Mattsson Håkan Mattsson Håkan Mattsson
2007-06-15
%VSN% megaco_intro.xml

Megaco/H.248 is a protocol for control of elements in a physically decomposed multimedia gateway, enabling separation of call control from media conversion. A Media Gateway Controller (MGC) controls one or more Media Gateways (MG).

This version of the stack supports version 1, 2 and 3 as defined by:

version 1 - RFC 3525 and H.248-IG (v10-v13)

version 2 - draft-ietf-megaco-h248v2-04 & H.248.1 v2 Corrigendum 1 (03/2004)

version 3:

prev3a - as defined by TD-33 (except segments)

prev3b - TD-33 updated to be backward compatible with v2 (except segments)

prev3c - As defined by ITU H.248.1 (09/2005) (except segments)

v3 - Full version 3 as defined by ITU H.248.1 (09/2005) (including segments)

The semantics of the protocol has jointly been defined by two standardization bodies:

IETF - which calls the protocol Megaco

ITU - which calls the protocol H.248

## Scope and Purpose

This manual describes the Megaco application, as a component of the Erlang/Open Telecom Platform development environment. It is assumed that the reader is familiar with the Erlang Development Environment, which is described in a separate User's Guide.

## Prerequisites

The following prerequisites is required for understanding the material in the Megaco User's Guide:

the basics of the Megaco/H.248 protocol

the basics of the Abstract Syntax Notation One (ASN.1)

familiarity with the Erlang system and Erlang programming

The application requires Erlang/OTP release R10B or later.

## About This Manual

In addition to this introductory chapter, the Megaco User's Guide contains the following chapters:

Chapter 2: "Architecture" describes the architecture and typical usage of the application.

Chapter 3: "Internal form and its encodings" describes the internal form of Megaco/H.248 messages and its various encodings.

Chapter 4: "Transport mechanisms" describes how different mechanisms can be used to transport the Megaco/H.248 messages.

Chapter 5: "Debugging" describes tracing and debugging.

## Where to Find More Information

Refer to the following documentation for more information about Megaco/H.248 and about the Erlang/OTP development system:

version 1, RFC 3525

old version 1, RFC 3015

Version 2 Corrigendum 1

version 2, draft-ietf-megaco-h248v2-04

TD-33 (Draft H.248.1 version 3)

H.248.1 version 3

the ASN.1 application User's Guide

the Megaco application Reference Manual

Concurrent Programming in Erlang, 2nd Edition (1996), Prentice-Hall, ISBN 0-13-508301-X.