AAA architectures applied in multi-domain IMS (IP multimedia subsystem)

There is a group of communication services that use\ud resources from multiple domains in order to deliver their service.\ud Authorization of the end-user is important for such services,\ud because several domains are involved. There are no current\ud solutions for delivering authentication, authorization and\ud accounting (AAA) to multi-domain services. In our study we\ud present two architectures for the delivery of AAA to such\ud services. The architectures are analyzed on their qualitative\ud aspects. A result of this analysis is that direct interconnection of\ud AAA servers is an effective architectural solution. In current\ud multi-domain IP Multimedia Subsystem (IMS) architectures,\ud direct interconnection of AAA servers, such as the Home\ud Subscriber Servers (HSS), is not yet possible. In this paper we\ud argue and recommend to extend the IMS specification by adding\ud a new interface to HSS in order to support the direct\ud interconnection of HSS/AAA servers located in different IMS\ud administrative domains

Redundancy Strategies for a High Splitting Optically Amplified Passive Optical Network

Copyright IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.High splitting, optically amplified, passive optical networks (SuperPONs) are investigated in terms of redundancy provision and protection mechanisms. Options for redundancy, including the important special case of dual homing, are detailed, and it is determined as to which of these options (duplication of the feeder and first distribution section, and N+1 protection of the optical amplifiers in the amplified splitter) would be required to be provided to all attached users to facilitate appropriate availability of the basic telephony service. The distributed amplified splitter dual homing solution is found to outperform the single amplified splitter solution in terms of its survivability. The protection mechanisms necessary to automatically switch to the redundant provision are discussed and it is seen that with the aid of suitable regular precautionary procedures protection switching can generally be provided rapidly (<50 ms). Finally, an availability, and cost versus availability, study confirms the aforementioned redundancy assessment for fiber-to-the-home (FTTH) implementations, but shows fiber-to-the-curb (FTTC) as needing additional redundancyPeer reviewe

Upcoming standards for CDN interconnect, presentation at IP&TV World Forum, 24-3-2011

This presentation was given at IP&TV World Forum, London, 24 March 2011. This presentation provides an overview of upcoming standards for the interconnection of Content Delivery Networks (CDN). The concept of CDN and CDN interconnection is explained by using the metafore of printing companies that may collaborate in the printing of newspapers. The presentation introduces relevant terminology, like the "Upstream CDN" and "Downstream CDN". It also highlights activities, technical approaches and time lines of the standardization activities in ETSI MCD and IETF

Actividad propia del alumno en psicología social de la salud

zip comprimit. Pàgina inicial: 220/index.htmlEl present treball és una Webquest que conté l'explicació de l'Activitat Pròpia de l'Alumnat, on s'exposa com fer una recerca bibliogràfica a través de les bases de dades nacionals i/o internacionals sobre un tema d'interés integrat en el temari de l'assignatura de Psicología de la Salut. Aquesta activitat forma part de la segona unitat (Psicología Social de la Salut) de l'assignatura, que pertany al pla docent de la licenciatura de Psicologia de la Universitat de Barcelona. La present Webquest está formada per cinc parts (introducció, tasques, procés, evolució i conclusions), a través de les quals exposem pas a pas el treball que ha de realitzar l'alumnat, tant de contingut, procediment i avaluació del mateix, amb una guia de materials de consulta (links) per a orientar el seu treball de recerca.El siguiente trabajo es una Webquest que contiene la explicación de la Actividad Propia del Alumnado, donde se expone como hacer una búsqueda bibliográfica con bases de datos nacionales y/o internacionales sobre un tema de interés integrado en el temario de la asignatura de Psicología de la Salud. Esta actividad forma parte de la segunda unidad (Psicología Social de la Salud) de la asignatura, dentro del plan docente de la licenciatura de Psicología de la Universidad de Barcelona. La Webquest está formada por cinco partes (introducción, tareas, proceso, evolución y conclusiones), a través de las que exponemos los pasos que debe seguir el alumnado para realizar el trabajo, en relación al contenido, procedimiento y evaluación del mismo. Añadimos una guía de materiales de consulta (links) para orientar su trabajo de recerca.The following work is a Webquest that contains the explanation of the Own Activity of the Pupils, where is exposed since to make a bibliographical search with national and/or international data bases on a subject of interest integrated in the agenda of the subjet of Psychology of the Health. This activity comprises of the second unit (Social Psychology of the Health) of the subject, within the educational plan of the degree of Psychology of the Universitat of Barcelona. The Webquest is formed by five parts (introduction, tasks, process, evolution and conclusions), through which exposes the steps that must follow the pupils to make the work, in relation to the content, procedure and evaluation of he himself. We added a guide of consultation materials (links) to orient its bibliographical work search

Gevaar VoIP voor telecomsector overdreven

Het is een hype Voice-over-IP (VoIP) voor te stellen als een ontwrichtende technologie die de telecomindustrie ingrijpend zal veranderen. Maar hoe ontwrichtend is VoIP eigenlijk? Oskar van Deventer en Marc van Wegberg analyseren drie vormen van VoIP en laten zien dat alleen ‘VoIP-chat’ potentieel een bedreiging is voor telefoniebedrijven

Experimental demonstration of a simple, optically transparent, add/drop multiplexer at 2.5 Gb/s without local optical source

We present a novel add/drop multiplexer and experimentally demonstrate its operation at 2.5 Gb/s. No local laser is needed since the wavelength- and modulation format transparent 'add' is accomplished by using optical switches, delay lines and the 'dropped' input. Applications are found in flexible, high capacity WDM networks

Evolution of the Converged NGN Service Platforms Towards Future Networks

This article presents a comparison of main characteristics of the Next Generation Networks (NGN) and Future Generation Internet (FGI). The aim is to discuss and compare two approaches to Future Networks (FN) and services: the evolution of NGN, and the revolutionary approach of a new FGI. We present both frameworks from the services point of view as they are delivered to the end-user, as well as from the architectural point of view. We compare selected properties of both approaches to explain commonalities and differences. Their challenges are similar: managing the quality of experience, mobility, security, scalability and providing openness to applications. Based on this comparison, we evaluate possible areas for future convergence in the approach of the two architectures to the Future Network concept. Our analysis shows that despite their different backgrounds, the internet’s FGI and telco’s NGN are not that different after all. The convergence of the two approaches therefore seems the only logical way forward