Media Gateway Overview

Media Gateway (MG) Framework implements the media mapping and transformation function identified in the decomposed Gateway architecture proposed by ETSI TIPHON and adopted by IETF. Media Gateway Framework from Aricent can be combined with its Media Gateway Controller (MGC), Softswitch and Gatekeeper Frameworks to quickly build converged voice/data solutions.

MG Framework Context	MG Framework Architecture

Media Gateway Framework is a portable software building block that can be used to build different types of gateway platforms in the converged next generation networks. The Media Gateway Framework alleviates the need to develop a new solution or to integrate multiple stacks from different vendors.

Aricent's Media Gateway Framework: Context

The Media Gateway framework is designed as an integrated unit that provides external interfaces to hardware and DSP firmware as well as functionality for configuration, control and management. The Media Gateway Framework can be interfaced to different hardware platforms by building a thin adaptation layer to map the framework DSP/Signaling driver to the platforms API hardware. Media Gateway Framework can be easily extended to support new packages by developing specific APIs and End-Point controllers. Context of the Media Gateway Framework is shown below:

Media Gateway Framework Context in System

Aricent's Media Gateway Framework: Functions

MEGACO Protocol Functions

• Manages associations with one or more Media Gateway Controllers in a network. This includes registration, de-registration, failure and changeover management
• Manages transactions with each of the Media Gateway Controllers it has registered with. Transaction management includes transaction creation, transaction deletion, in sequence and reliable transaction transport and execution of commands in a transaction

Resource Management Function

• Manages media resources like terminations, codecs, announcement servers, etc., contained within it. This involves reservation, release, provisioning, maintenance and reporting of status to the Media Gateway Controller of these resources

Media Stream Processing Functions

• Performs various media processing functions like media transcoding, media insertion, echo cancellation, modulation/demodulation, voice activity detection
• Responsible for transport of voice to the other end of the packet network using RTP/RTCP to another Media Gateway or a Terminal
• Handles creation & deletion of media connections among media resources of Media Gateway
• Reports usage and QoS statistics for each connection established by it to the Media Gateway Controller
• Reports all events occurring in the media streams, and also applies signals to the media streams when requested by the Media Gateway Controller
• Collects digits received in the media stream based on the digit map downloaded by the Media Gateway Controller when it is required to send digits en bloc

Media Gateway Framework can be interfaced to different hardware by developing specific APIs and End-Point controllers (elements outlined in Red). A high level architecture of the Media Gateway Framework is depicted below:

Media Gateway Framework high level architecture

Administration and Maintenance Functions

• Provides configuration interface to the user to provision Media Gateway with different resources
• The Media Gateway software is responsible for maintenance functions such as health and status monitoring, failure management and failure reporting to the user
• Permits different levels of tracing of the Media Gateway software
• Responsible for accumulation of different statistics that can be used for optimal provisioning of the Media Gateway and enhancing its performance