Steven Vermeulen

An end to end QoS discovery architecture embedded in a TINA based multimedia platform

In this paper we envisage the issue of quality of service (QoS) management for multimedia services as an end to end QoS discovery problem. With this perception as a basis, we designed and implemented a layered QoS management architecture which handles QoS from the users perspective, as well as from the end systems and the networks perspective. The architecture is decomposed into three layers. First there is the QoS specification, presentation and parameterization layer at which an end user is able to specify his/her QoS requirements in a comprehensible and qualitative way, and at which these QoS requirements are translated into parameterized terminal capabilities. Secondly, there is the QoS matching and negotiation layer at which the parameterized QoS capabilities of different terminal end systems are marched and compared in order to search for a QoS equilibrium. Finally, there is the QoS implementation layer which implements the resolved QoS equilibrium in the network and in the terminals. This generic architecture, which allows a de-abstraction of user defined QoS, has been implemented in the context of a CORBA based TINA platform.

A generic architecture for management and control of end-to-end quality of service over multiple domains

Currently, service providers and network operators are exploring new business opportunities that can be found in offering packages of advanced highly customized services to both residential and corporate subscribers. The semantics of these services will be more sophisticated, their access will be better controlled, their usage will be more flexible in time (scheduled) and space (mobile access), and their delivery will be possible with different grades of Quality of Service (QoS). Multimedia services such as video conferencing, distance learning, tele surgery, or dynamic and scheduled trunk provisioning, subject to certain Subject Level Agreements (e.g. corporate VPNs), are just a few examples of services with higher semantics. Although these services could have a high market potential, their implementation and delivery are hampered by the lack of an efficient, flexible and integrated network and service management system. Particularly, in the network management domain we encounter the following three problems. First, the setup of multimedia streams with end-to-end QoS over multiple administrative business domains is impossible without adequate federating mechanisms between network management systems. Secondly, dynamic and flexible interworking mechanisms between different technology domains is ubiquitous for the automatic provisioning of trails over a set of heterogeneous networked systems (e.g. from ATM in the access to IP in the core, from MPLS to DWDM, or from Frame Relay to ATM). Third, management of end-to-end QoS is not only a matter of network QoS. Management of QoS in end terminals and end devices or at a web server is an integral part of the global QoS delivery process. The Telecommunications Information Networking Architecture (TINA) has defined a distributed and integrated computational platform for the management and delivery of QoS based services. This paper starts from a state of the art TINA system and elaborates potential enhancements and extensions in order to bring a solution for each of the three previous issues.

XML and CORBA, Synergistic or Competitive?

The extensible Markup Language (XML) is gaining a lot of attention in the Internet world and is adopted by major companies (IBM, Microsoft, Oracle). XML, the open-standards child of SGML, promises to provide platform- and language neutral data encapsulation and separates application logic from application data. Meanwhile, various object-oriented technologies and standards such as Java and CORBA have also progressed rapidly in the past few years. Java is being presented as the perfect partner for XML. Java supports the development of Web-aware, platform-neutral applications, and XML is a platform-neutral document description meta-language. But doesn’t CORBA promise exactly the same? This paper describes the XML and CORBA ‘approaches’, and the synergies and/or competition between these technologies, taking into account the “philosophy” of each approach. Different criteria are identified where comparison is possible and relevant, such as: specification (e.g. expressive power), deployment (parsing, marshalling, scalability), and tools. XML is the next step in Web-protocols (after IP, HTML). It is concluded that XML can in conjunction with a multitude of other protocols provide the same functionality as CORBA, but will only replace CORBA in those cases where using CORBA is undesirable.

Dynamically configurable protocol stacks

This paper presents a generic architecture for multimedia terminals with respect to the management and implementation of dynamic and programmable protocol stacks. This architecture is built around the combination of CORBA based management components and real-time multimedia data processing engines. The management objects export a set of easily usable interfaces, which allow cascading and configuring the engines in such a way that they terminate multimedia network connections with the desired protocol stack. Terminal software components, which are designed according to existing multimedia delivery standards (such as TINA or H.323) can be easily integrated with these CORBA components in order to introduce dynamic programmable multimedia endpoints in the terminal(s).