I. Introduction to the Internet Multimedia

IEEE Communications Surveys & Tutorials, 2000

One of the major challenges for next generation IP networks is to provide multimedia teleconferencing services. Moreover, the introduction of new services includes the take over of traditional telephony. Besides the general problems with supporting realtime services in the IP network (e.g. QoS), this puts a special interest on the control of supplementary services and on the mechanisms for their fast and efficient development and deployment. The two most promising approaches in the multimedia over IP area are the protocol suites H.323 (ITU-T) and SIP (IETF). Several comparisons of these two protocols have been published already, but their service architectures have been rarely addressed. This survey provides a comparison of H.323 and SIP, focussing on their service architectures. The basic protocol architectures are reviewed, followed by an in-depth evaluation of their service implementation mechanisms. The studies are backed up by detailed examples for the control of supplementary services in H.323 and SIP. Although the two protocol architectures are quite similar, it is shown that there are considerable differences regarding their supplementary service architectures. H.323/H.450, which is still the more mature standard, has been focussed on supplementary services, smooth interworking with the PSTN and interoperability between different implementations. It has clear advantages for IP telephony applications. SIP has been designed with a broader scope, providing more generic syntax and semantics regarding feature definition and session description. Since the standards do not describe all details for broad range of possible applications and services, this bears the danger of interoperability problems. SIP has advantages for non-VoIP services. A coexistence of both protocols can be foreseen, stressing the importance of interworking between them.

Communications - Scientific letters of the University of Zilina, 2004

Proceedings IEEE INFOCOM 2000. Conference on Computer Communications. Nineteenth Annual Joint Conference of the IEEE Computer and Communications Societies (Cat. No.00CH37064)

2008

Since the late 90's IP telephony, commonly referred to as Voice over IP (VoIP), has been presented as a revolution on communications enabling the possibility to converge historically separated voice and data networks, reducing costs, and integrating voice, data and video on applications. This paper presents a study over the standard VoIP protocols H.323, session initiation protocol (SIP), media gateway control protocol (MGCP), and H.248/Megaco. Given the fact that H.323 and SIP are more widespread than the others, we focus our study on them. For each of these protocols we describe and discuss its main capabilities, architecture, stack protocol, and characteristics. We also briefly point their technical limitations. Furthermore, we present the advanced multimedia system (AMS) project, a new system that aims to operate on Next Generation Networks (NGN) taking the advantage of its features, and it is viewed as the successor to H.323 and SIP.

Elektrotechnik Und Informationstechnik, 2006

This paper describes the IP Multimedia Subsystem (IMS), a Service Delivery Platform architecture for providing multimedia applications in converging fixed and mobile IP networks, called Next Generation Networks (NGN). It introduces the IMS architecture, which represents a combination of the classic Intelligent Network concept of the telecom world and current Internet protocols, and highlights the main IMS components and control features for the provision of multimedia information and communication services. Furthermore, the paper is focusing on the IMS Quality of Service (QoS) aspects defined within 3GPP IMS and ETSI TISPAN NGN. Dieser Artikel beschreibt die IP-Multimedia-Subsystem(IMS)-Architektur als Dienstplattform für multimediale Informations- und Kommunikationsanwendungen in konvergierenden Netzen, auch Next Generation Networks (NGN) genannt. Nach einer Einführung der IMS-Architektur, die auf einer Kombination der klassischen Intelligenten Netze- und aktuellen Internetprotokollen basiert, werden die IMS-Hauptkomponenten sowie die Kontrollflüsse zur Bereitstellung von Multimediadiensten beleuchtet. Weiterhin konzentriert sich der Artikel auf die in der 3GPP und ETSI TISPAN NGN standardisierten IMS-Dienstgüteaspekte.

IP Multimedia services provide a dynamic combination of voice, video, messaging, data, etc. within the same session. By increasing the number of basic applications and the media that it is possible to combine, it is possible to increase the number of services offered to the end users, and thus to enrich the interpersonal communication experience. IPTV is a system used to deliver digital television services to the consumers through broadband. This delivery of digital television is made possible by using Internet Protocol over a broadband connection, usually in a managed network rather than the public Internet to preserve quality of service guarantees. The Internet Protocol (IP) Multimedia Subsystem, better known as "The IMS", is based on the specification of the Session Initiation Protocol (SIP) as standardized by the Internet Engineering Task Force (IETF). The IMS is an architecture for the convergence of data, speech and mobile networks and is based on a wide range of protocols, of which most have been developed by the IETF. It combines and enhances them to allow real time services on top of the Universal Mobile Telecommunications System (UMTS) packet-switched domain. This paper presents what IPTV is, its requirements, how IPTV will be merged with IMS and various standardization efforts for IPTV. It further also deals the advantage of IMS based IPTV, its implementation challenges, performance and capacity, and testing requirement.

The IP Multimedia Subsystem (IMS) is the evolution of the UMTS network towards an All-IP network supporting all the services working today through switched circuits plus new multimedia services (video call, VoIP, video streaming, presence, instant messaging, web access, etc.). As new services may require high restrictions in network parameters, the support for Quality of Service (QoS) is necessary. This paper reviews the evolution towards All-IP convergent environments of the main mobile telecommunication systems and introduces a SIP-IMS simulation model to allow performance evaluation of different IMS scenarios.

Bell Labs Technical Journal, 2004

Media services have played an important role in the traditional time division multiplexing (TDM)-based telephone network. As the network migrates to an Internet Protocol (IP)-based environment, media services are also moving to new environments. This paper reviews the background of media services and examines current trends in the telecommunications and Internet industries to identify implications for the future of such services in IP networks, especially in Session Initiation Protocol (SIP)-based environments. One of the most exciting trends is the emergence and adoption of complementary modular standards that leverage the Internet to enable media services to be developed, deployed, and updated more rapidly than before in a network architecture that supports concepts we call provisioning on demand and scaling on demand. This paper discusses how these new standards facilitate these concepts and how the concepts can be applied to create a media server that requires no preprovisioned service-specific logic or service-specific resources (e.g., announcements and grammars). It also provides an overview of the Bell Labs media server prototype, which has been developed to support and explore this vision. © 2004 Lucent Technologies Inc.

Mobile Information Systems, 2007

2007

Internet access has been, until now, the main driver for the generalization of broadband connections in the residential market. Simple IP based services like email and web browsing were, during many years, the typical services provided to residential customers. Today the telecommunications market is changing and operators are looking for ways to provide, through those same IP broadband connections, value added services. These will, in one hand, increase their revenues and on the other hand, provide to the customer a wider range of services until now inaccessible. Triple Play is already a reality, although, the convergence between mobile and fixed networks is bringing to the home a new range of IP Multimedia Subsystem (IMS) based services, which used to be exclusive of the mobile world. Although, to successfully achieve the delivery of these new services, the interface between residential and operator’s networks must be meticulously defined and implemented, by what is usually called ...