JBoss.orgCommunity Documentation

Chapter 1. Introduction to the JBoss Communications Media Server

1.1. Introduction
1.2. The Justification for S/w Media Server
1.3. What is JBoss Communications Media Server
1.4. Media Server Use Case

In the world of telephony, a media server is the name given to the computing component that processes the audio and/or video streams associated with telephone calls or connections. Conference services are a particular example of how media servers can be used, as a special 'engine' is needed to mix audio streams together so that conference participants can hear all of the other participants. Conferencing servers may also need other specialized functions like "loudest talker" detection, or transcoding of audio streams, and also interpreting DTMF tones used to navigate menus also known as Interactive Voice Response (IVR). For video processing, it may be needed to change video streams, for example transcode from one video codec to another or rescale (transrate) a picture from one size to another. This media processing functions are the core responsibility of a media server. Few of the real Media Server Use Cases are defined here.

Media Server can be Hardware Media Server or Software Based. The Hardware Media Server uses the hardware components for processing the audio/video. Depending on which hardware media server, there would be individual hardware dedicated to do specific job for example reduction of echo etc. In case of Software Media Server all the audio/video processing is done by a software, no specifc hardware is used.

Today, all communications can be routed through computers. Widespread access to broadband Internet and the ubiquity of Internet Protocol (IP) enable the convergence of voice, data and video. Media Servers provide the ability to switch voice media between a network and its access point. Using Digital Subscriber Line (DSL) and fast-Internet cable technology, a software media server converts, compresses and packetizes voice data for transmission back-and-forth across the Internet backbone for landline and wireless phones. Media gateways sit at the intersection of Public Switched Telephone Networks ( PSTNs) and wireless or IP-based networks.

Multiple market demands are pushing companies to converge all of their media services using media gateways with Voice-over-IP ( VoIP ) capabilities. Companies have expectations for such architectures, which include:

With telephony networks moving more towards VoIP technology, and using Session Initiation Protocol (SIP), the idea of media servers has started to gain some traction. Typically, an application (the 'application server') has the controlling logic, and controls a remote media server (or multiple servers) over an IP connection using various industry recognized standard protocols like MGCP, MEGACO (H.248), MSML, VoiceXML etc. The JBoss Communications Media Server is first and only open source media server available as of today that has support for MGCP. The Mobicents also has JSR-309 Standard Api implementation to control media servers irrespective of underlying protocol used. Hence Application's developed on any platform can control JBoss Communications Media Server using JSR-309 API.

The Mobicents Media Server core is based on software components only. This property allows to easy scale from development environment on a single server to production deployment in a distributed network environment. Mobicents Media Server binary is distributed in two forms: standalone server which is recommended for production deployments and integrated with JBoss 5 Application server which is more preferred for development purposes.

Because Mobicents Media Server is Java based, it is cross platform, easy to install and run on any operating system that supports Java. The available source code is a powerful tool to debug the server and understand processing logic. It also gives you the flexibility to create customized components and configurations for your personal or business use.

Media Server's are heavily used in conventional applications across various market segments for example the Mobile / PSTN service provider have media server's to play announcements like "The user is busy, please call after some time" or to record the voice message when the called party is busy and to re-play the same message when asked for.

The IVR Applications used by various segments of industry, for example IVR system used in banks to let their customers know their balance by calling a Toll-Free-Number or do other banking transactions.

Developing a converged application has now become very easy with availability of Open Source JBoss Communications Media Server. Appart from conventional Applications like IVR, Conferencing, various Tone (like busy, congestion etc) generation/detection below are few Use Cases that can be developed using Mobicents Media Server and Mobicents Platform.

Developing Converged Applications

A Converged Application delivers data, voice, video to end user on any device like Public Switch Telephone Network (land line/mobile) or VoIP Phones or any other device on any network like SS7, IP etc. There is no limitation on what kind of Converged Application can be developed by using the Mobicents Media Server.

Innovation in Traditional Telco Value Added Service

As explained in above paragraphs, traditional telco value added service's like Ring Back Tone (RBT), Voice Message, Call Forwarding, Call Blocking are quite common terms now. But to subscribe/unsbscribe for each of these service, to manage these service is hassle as each of them are different service in it-self. How about a Portal where customer can log in and manage all its service that he/she is subscribed to? The Portal also gives an Rule based call routing option to let user decide where the call gets routed (his/her mobile,land phone,business phone,home phone etc) depending on which time of day the call arrives. How about letting the user record the converstaion by press of a button and latter through Portal user can listen, download, forward mail as attachment. Let user upload his/her favorite mp3 songs on portal which then can be used as personalized RBT for individual callers calling the user. Let user record the message like "This Phone is out of service for next 6 months. Please call after 6 months" and play it when any unwanted caller calls ;). Basically its a call-blocking service but with much more flexibility! Even Presence service can be leveraged to develop more interesting apps.

Capitalize on next Generation Netwrok - IMS

In order to create innovative, cost effective and felxible applications and to reduce time to market and meet customer demands, the transition should happen from legacy SS7 network to IP based Multimedia Subsystem (IMS). Mobicents Media Server can act as IMS - Media Resource Function (MRF) that caters to media needs within IP based home netwroks.

Mobicents Media Server can also be deployed as PSTN gateway that converst the SIP signalling to SS7 signals (ISUP etc). On one side the Media Server is able to send and receive IMS media over the Real-Time Protocol (RTP). On the other side the Media Server uses one or more PCM (Pulse Code Modulation) time slots to connect to the SS7 network