Service Oriented Architecture for VoIP Conferencing”, to be

Voice/Video over IP (VoIP) systems to date have been either highly centralized or dependent on the IP multicast in nature. Global Multimedia Collaboration System is a scalable, integrated and service-oriented VoIP conferencing system, based on the XGSP col

Service Oriented Architecture for VoIP conferencing

Wenjun Wu1, Geoffrey Fox1 , Hasan Bulut1 , Ahmet Uyar2, Tao Huang1

1 Community Grids Computing Laboratory, Indiana University, USA 2 Department of Electrical Engineering and Computer Science, Syracuse University, USA

{wewu, gcf, hbulut, auyar, taohuang}@indiana.edu

Indiana University Research Park, 501 N Morton St. 222, Bloomington, IN, 47408, USA

Abstract

Voice/Video over IP (VoIP) systems to date have been either highly centralized or dependent on the IP multicast in nature. Global Multimedia Collaboration System is a scalable, integrated and service-oriented VoIP conferencing system, based on the XGSP collaboration framework and NaradaBrokering messaging middleware. This system can provide media and session services to heterogeneous endpoints such as H.323, SIP, Access Grid, RealPlayer as well as cellular phone. In this paper, we address the challenges of scalability, interoperablity and heterogeneity in massive VoIP conferencing system. We believe that our approach opens up new opportunities for leveraging classic VoIP systems by using new technologies in service-oriented computing.

Keywords

Videoconference, Service-Oriented Architecture, Global-MMCS, XGSP, NaradaBrokering,

1. Introduction

VoIP and videoconferencing systems are increasingly becoming a very important and popular application on the Internet. There are various solutions to such multimedia communication applications, among which H.323 [1], SIP [2], and Access Grid [3] are well-known. It will bring substantial benefits to Internet users if we can build an integrated collaboration environment, which combines these systems into a single easy-to-use, intuitive environment. These emerging advanced distributed multimedia services demand a scalable, robust and adaptive service infrastructure. However, both the traditional telecommunication architecture based on client/server model and multicast based Internet model can’t naturally offer such a platform. Currently, service-oriented architecture is regarded as a promising solution to Internet applications such as peer-to-peer computing, Grid and Web-Services computing. It suggests a powerful vision for the future VoIP and videoconferencing systems.

We propose a service-oriented VoIP conferencing framework which can interoperate with standards –based VoIP systems to forge an open software solution that will leverage existing conferencing resources. XGSP (XML based General Session Protocol) [4] is an interoperable framework based on Web services technology for creating and controlling audio and videoconferences. Just like the text messages in SIP, XML should be used to describe the XGSP protocol because it makes the protocol easier to be understood and to interact with other Web based components.

Based on this framework, Global-MMCS (Global Multimedia Collaboration System) [5] is developed to support scalable web-service based interoperable VoIP conferences and integrate various services including videoconferencing, instant messaging and streaming. Global-MMCS uses a unified, scalable, QoS aware “overlay” network – NaradaBrokering [6], to support audiovisual and data group communication over heterogeneous networking environments. Using XGSP schema, Global-MMCS specifies a distributed flexible conference management mechanism for integration of various VoIP conferencing services, and a common audiovisual signaling protocol for interactions between different conferencing endpoints. Instead of following the telecommunication monolithic service provision which usually mixes the packet delivery, call control functions and service logic intelligence in the central hardware boxes, it separates the MCU/Softswitch in VoIP into distinct services for media delivery, media processing and session management. These services can be distributed and if needed replicated for performance and fault tolerance. On top of the messaging and VoIP media services infrastructure, rich multimedia collaborations can be built to meet the demands in different application scenarios. Also several Gateway services are developed to enable multimedia clients to interact with the core services.

The paper is organized in the following way. Section 2 introduces related work and our design principles. System architecture is discussed in Section 3. Section 4 presents the implementation of the system and performance evaluation. Section 5 gives the conclusion and points out the future work.

Voice/Video over IP (VoIP) systems to date have been either highly centralized or dependent on the IP multicast in nature. Global Multimedia Collaboration System is a scalable, integrated and service-oriented VoIP conferencing system, based on the XGSP col

2. Related Work

The VoIP conference has been existed over years. The well-known solutions include H.323, SIP and IETF MMUSIC [7]. Here we introduce them briefly and compare them with our design principles.

2.1 H.323 and SIP

H.323 is a communication standard produced by the ITU, initiated in late 1996, and aimed at the emerging area of multimedia communication over LANs. It is widely supported by many commercial vendors and used throughout the world in commercial and educational markets. H.323 is defined as an umbrella standard specifying the components to be used within an H.323-based environment. It provides conference management functionality for VoIP conferences using the call signaling functionality of H.225

[8], H.245 [9]. These protocols provide call set-up and call transfer of real-time connections to support small-scal …… 此处隐藏：44836字，全部文档内容请下载后查看。喜欢就下载吧 ……