Assessing and Improving Interoperability of Distributed Systems

Interoperabilität von verteilten Systemen ist eine Grundlage für die Entwicklung von neuen und innovativen Geschäftslösungen. Sie erlaubt es existierende Dienste, die auf verschiedenen Systemen angeboten werden, so miteinander zu verknüpfen, dass neue oder erweiterte Dienste zur Verfügung gestellt werden können. Außerdem kann durch diese Integration die Zuverlässigkeit von Diensten erhöht werden. Das Erreichen und Bewerten von Interoperabilität stellt jedoch eine finanzielle und zeitliche Herausforderung dar. Zur Sicherstellung und Bewertung von Interoperabilität werden systematische Methoden benötigt. Um systematisch Interoperabilität von Systemen erreichen und bewerten zu können, wurde im Rahmen der vorliegenden Arbeit ein Prozess zur Verbesserung und Beurteilung von Interoperabilität (IAI) entwickelt. Der IAI-Prozess beinhaltet drei Phasen und kann die Interoperabilität von verteilten, homogenen und auch heterogenen Systemen bewerten und verbessern. Die Bewertung erfolgt dabei durch Interoperabilitätstests, die manuell oder automatisiert ausgeführt werden können. Für die Automatisierung von Interoperabilitätstests wird eine neue Methodik vorgestellt, die einen Entwicklungsprozess für automatisierte Interoperabilitätstestsysteme beinhaltet. Die vorgestellte Methodik erleichtert die formale und systematische Bewertung der Interoperabilität von verteilten Systemen. Im Vergleich zur manuellen Prüfung von Interoperabilität gewährleistet die hier vorgestellte Methodik eine höhere Testabdeckung, eine konsistente Testdurchführung und wiederholbare Interoperabilitätstests. Die praktische Anwendbarkeit des IAI-Prozesses und der Methodik für automatisierte Interoperabilitätstests wird durch drei Fallstudien belegt. In der ersten Fallstudie werden Prozess und Methodik für Internet Protocol Multimedia Subsystem (IMS) Netzwerke instanziiert. Die Interoperabilität von IMS-Netzwerken wurde bisher nur manuell getestet. In der zweiten und dritten Fallstudie wird der IAI-Prozess zur Beurteilung und Verbesserung der Interoperabilität von Grid- und Cloud-Systemen angewendet. Die Bewertung und Verbesserung dieser Interoperabilität ist eine Herausforderung, da Grid- und Cloud-Systeme im Gegensatz zu IMS-Netzwerken heterogen sind. Im Rahmen der Fallstudien werden Möglichkeiten für Integrations- und Interoperabilitätslösungen von Grid- und Infrastructure as a Service (IaaS) Cloud-Systemen sowie von Grid- und Platform as a Service (PaaS) Cloud-Systemen aufgezeigt. Die vorgestellten Lösungen sind in der Literatur bisher nicht dokumentiert worden. Sie ermöglichen die komplementäre Nutzung von Grid- und Cloud-Systemen, eine vereinfachte Migration von Grid-Anwendungen in ein Cloud-System sowie eine effiziente Ressourcennutzung. Die Interoperabilitätslösungen werden mit Hilfe des IAI-Prozesses bewertet. Die Durchführung der Tests für Grid-IaaS-Cloud-Systeme erfolgte manuell. Die Interoperabilität von Grid-PaaS-Cloud-Systemen wird mit Hilfe der Methodik für automatisierte Interoperabilitätstests bewertet. Interoperabilitätstests und deren Beurteilung wurden bisher in der Grid- und Cloud-Community nicht diskutiert, obwohl sie eine Basis für die Entwicklung von standardisierten Schnittstellen zum Erreichen von Interoperabilität zwischen Grid- und Cloud-Systemen bieten.Achieving interoperability of distributed systems offers means for the development of new and innovative business solutions. Interoperability allows the combination of existing services provided on different systems, into new or extended services. Such an integration can also increase the reliability of the provided service. However, achieving and assessing interoperability is a technical challenge that requires high effort regarding time and costs. The reasons are manifold and include differing implementations of standards as well as the provision of proprietary interfaces. The implementations need to be engineered to be interoperable. Techniques that assess and improve interoperability systematically are required. For the assurance of reliable interoperation between systems, interoperability needs to be assessed and improved in a systematic manner. To this aim, we present the Interoperability Assessment and Improvement (IAI) process, which describes in three phases how interoperability of distributed homogeneous and heterogeneous systems can be improved and assessed systematically. The interoperability assessment is achieved by means of interoperability testing, which is typically performed manually. For the automation of interoperability test execution, we present a new methodology including a generic development process for a complete and automated interoperability test system. This methodology provides means for a formalized and systematic assessment of systems' interoperability in an automated manner. Compared to manual interoperability testing, the application of our methodology has the following benefits: wider test coverage, consistent test execution, and test repeatability. We evaluate the IAI process and the methodology for automated interoperability testing in three case studies. Within the first case study, we instantiate the IAI process and the methodology for Internet Protocol Multimedia Subsystem (IMS) networks, which were previously assessed for interoperability only in a manual manner. Within the second and third case study, we apply the IAI process to assess and improve the interoperability of grid and cloud computing systems. Their interoperability assessment and improvement is challenging, since cloud and grid systems are, in contrast to IMS networks, heterogeneous. We develop integration and interoperability solutions for grids and Infrastructure as a Service (IaaS) clouds as well as for grids and Platform as a Service (PaaS) clouds. These solutions are unique and foster complementary usage of grids and clouds, simplified migration of grid applications into the cloud, as well as efficient resource utilization. In addition, we assess the interoperability of the grid-cloud interoperability solutions. While the tests for grid-IaaS clouds are performed manually, we applied our methodology for automated interoperability testing for the assessment of interoperability to grid-PaaS cloud interoperability successfully. These interoperability assessments are unique in the grid-cloud community and provide a basis for the development of standardized interfaces improving the interoperability between grids and clouds

Dynamic service composition for telecommunication services and its challenges

As communication networks have evolved towards IP (Internet Protocol) networks, telecommunication operators has expanded its reach to internet multimedia web content services while operating circuit-switch networks in parallel. With the adoption of SOA (Service Oriented Architecture) that enables service capability interfaces to be published and integrated with other service capabilities into new composite service, service composition allows telecommunication providers to accelerate more new services provisioning. From the perspective of telecommunication providers to deliver integrated composite service from different providers and different network protocols, this paper is aimed to present the current service composition based on middleware approaches; discuss the requirements of meeting the challenges; and compare the approaches

Ensuring interoperability between network elements in next generation networks

Next Generation Networks (NGNs), based on the Internet Protocol (IP), implement several services such as IP-based telephony and are beginning to replace the classic telephony systems. Due to the development and implementation of new powerful services these systems are becoming increasingly complex. Implementing these new services (typically software-based network elements) is often accompanied by unexpected and erratic behaviours which can manifest as interoperability problems. The reason for this caused by insufficient testing at the developing companies. The testing of such products is by nature a costly and time-consuming exercise and therefore cut down to what is considered the maximum acceptable level. Ensuring the interoperability between network elements is a known challenge. However, there exists no concept of which testing methods should be utilised to achieve an acceptable level of quality. The objective of this thesis was to improve the interoperability between network elements in NGNs by creating a testing scheme comprising of three diverse testing methods: conformance testing, interoperability testing and posthoc analysis. In the first project a novel conformance testing methodology for developing sets of conformance test cases for service specifications in NGNs was proposed. This methodology significantly improves the chance of interoperability and provides a considerable enhancement to the currently used interoperability tests. It was evaluated by successfully applying it to the Presence Service. The second report proposed a post-hoc methodology which enables the identification of the ultimate causes for interoperability problems in a NGN in daily operation. The new methods were implemented in the tool IMPACT (IP-Based Multi Protocol Posthoc Analyzer and Conformance Tester), which stores all exchanged messages between network elements in a database. Using SQL queries, the causes for errors can be found efficiently. Overall the presented testing scheme improves significantly the chance that network elements interoperate successfully by providing new methods. Beyond that, the quality of the software product is raised by mapping these methods to phases in a process model and providing well defined steps on which test method is the best suited at a certain stage

Designing and prototyping WebRTC and IMS integration using open source tools

WebRTC, or Web Real-time Communications, is a collection of web standards that detail the mechanisms, architectures and protocols that work together to deliver real-time multimedia services to the web browser. It represents a significant shift from the historical approach of using browser plugins, which over time, have proven cumbersome and problematic. Furthermore, it adopts various Internet standards in areas such as identity management, peer-to-peer connectivity, data exchange and media encoding, to provide a system that is truly open and interoperable. Given that WebRTC enables the delivery of multimedia content to any Internet Protocol (IP)-enabled device capable of hosting a web browser, this technology could potentially be used and deployed over millions of smartphones, tablets and personal computers worldwide. This service and device convergence remains an important goal of telecommunication network operators who seek to enable it through a converged network that is based on the IP Multimedia Subsystem (IMS). IMS is an IP-based subsystem that sits at the core of a modern telecommunication network and acts as the main routing substrate for media services and applications such as those that WebRTC realises. The combination of WebRTC and IMS represents an attractive coupling, and as such, a protracted investigation could help to answer important questions around the technical challenges that are involved in their integration, and the merits of various design alternatives that present themselves. This thesis is the result of such an investigation and culminates in the presentation of a detailed architectural model that is validated with a prototypical implementation in an open source testbed. The model is built on six requirements which emerge from an analysis of the literature, including previous interventions in IMS networks and a key technical report on design alternatives. Furthermore, this thesis argues that the client architecture requires support for web-oriented signalling, identity and call handling techniques leading to a potential for IMS networks to natively support these techniques as operator networks continue to grow and develop. The proposed model advocates the use of SIP over WebSockets for signalling and DTLS-SRTP for media to enable one-to-one communication and can be extended through additional functions resulting in a modular architecture. The model was implemented using open source tools which were assembled to create an experimental network testbed, and tests were conducted demonstrating successful cross domain communications under various conditions. The thesis has a strong focus on enabling ordinary software developers to assemble a prototypical network such as the one that was assembled and aims to enable experimentation in application use cases for integrated environments

Study, Analysis and Modeling of IP Multimedia systems on next generation networks providing mobile and fixed multimedia services

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Inter-domain interoperability framework based on WebRTC

Nowadays, the communications paradigm is changing with the convergence of communication services to a model based on IP networks. Applications such as messaging or voice over IP are increasing its popularity and Communication Service Providers are focusing on offering this kind of services. Moreover, Web Real Time Communication (WebRTC) has emerged as a technology that eases the creation of web applications featuring Real-Time Communications over IP networks without the need to develop and install any plug-in. It lacks of specifications in the control plane, leaving the possibility to use WebRTC over tailored web signalling solutions or legacy networks such as IP Multimedia Subsystem (IMS). This technology brings a wide range of possibilities for web developers, but Communication Service Providers are adviced to develop solutions based on the WebRTC technology as described in the Eurescom Study P2252. The lack of WebRTC specifications on the signalling platform together with the threats and opportunities that this technology represents for Communication Service Providers, makes evident the need of research on interoperability solutions for the different kind of signalling implementations and experimentation on the best way for Communication Service Providers to obtain the maximum benefit from WebRTC technology. The main goal of this thesis is precisely to develop a WebRTC interoperability framework and perform experiments on whether the Communication Service Providers should use their existing IMS solutions or develop tailored web signalling platforms for WebRTC deployments. In particular, the work developed in this thesis was completed under the framework of the Webrtc interOperability tested in coNtradictive DEployment scenaRios (WONDER) experimentation for the OpenLab project. OpenLab is a Large-scale integrating project (IP) and is part of the European Union Framework Programme 7 for Research and Development (FP7) addressing the work programme topic Future Internet Research and Experimentation.Actualmente, el paradigma de comunicaciones está cambiando gracias a la convergencia de los servicios de comunicaciones hacia un modelo basado en redes IP. Aplicaciones tales como la mensajería y la voz sobre IP están creciendo en popularidad mientras los proveedores de servicios de comunicaciones se centran en ofrecer este tipo de servicios basados en redes IP. Por otra parte, la tecnología WebRTC ha surgido para facilitar la creación de aplicaciones web que incluyan comunicaciones en tiempo real sobre redes IP sin la necesidad de desarrollar o instalar ningún complemento. Esta tecnología no especifica los protocolos o sistemas a utilizar en el plano de control, dejando a los desarrolladores la posibilidad de usar WebRTC sobre soluciones de señalizaci on web específicas o utilizar las redes de señalización existentes, tales como IMS. WebRTC abre un gran abanico de posibilidades a los desarrolladores web, aunque también se recomienda a los proveedores de servicios de comunicaciones que desarrollen soluciones basadas en WebRTC como se describe en el estudio P2252 de Eurescom. La falta de especificaciones en el plano de señalización junto a las oportunidades y amenazas que WebRTC representa para los proveedores de servicios de comunicaciones, hacen evidente la necesidad de investigar soluciones de interoperabilidad para las distintas implementaciones de las plataformas de señalización y de experimentar c omo los proveedores de servicios de comunicaciones pueden obtener el máximo provecho de la tecnología WebRTC. El objetivo principal de este Proyecto Fin de Carrera es desarrollar un marco de interoperabilidad para WebRTC y realizar experimentos que permitan determinar bajo que condiciones los proveedores de servicios de comunicaciones deben utilizar las plataformas de se~nalizaci on existentes (en este caso IMS) o desarrollar plataformas de señalización a medida basadas en tecnologías web para sus despliegues de WebRTC. En particular, el trabajo realizado en este Proyecto Fin de Carrera se llevó a cabo bajo el marco del proyecto WONDER para el programa OpenLab. OpenLab es un proyecto de integración a gran escala en el cual se desarrollan investigaciones y experimentos en el ámbito del futuro Internet y que forma parte del programa FP7 de la Unión Europea.Ingeniería de Telecomunicació

SMS over LTE : interoperability between legacy and next generation networks

To increase the trust and acceptance of Next Generation Networks (NGN) by new and existing subscribers, it is necessary to ensure that the most popular services of legacy networks (GSM/GPRS) are still in place. The Short Message Service (SMS) is a widespread data service with high revenue for telecommunication operators, which allows the exchange of short messages between fixed, mobile and, indirectly, Internet subscribers. In this context, it is essential to extend this service for the NGN and allow its interaction with the new messaging services. With that in mind, a study was carried out to ensure the coexistence between SMS and the Instant Messaging (IM) service present in NGN. The present study identifies the relevant technical specifications impacting on the functionality of the IP Multimedia Subsystem (IMS) messaging services so that the interoperability with SMS can be ensured. The results of this study, covered in this article, aim to help the comprehension of the proposed interoperability solution, and demonstrate that the exchange of messages between legacy and NGN messaging services or equipment can be successfully accomplished. In this context, both SMS and IMS messaging services are detailed, along with the main protocols they involve. Finally, the entity responsible for ensuring message interoperability - the IP Short Message Gateway (IP-SM-GW) - is presented and tested in a commercial delivery content testbed.(undefined

Towards a scalable video interactivity solution over the IMS

Includes bibliographical references (leaves 72-76).Rapid increase in bandwidth and the interactive and scalability features of the Internet provide a precedent for a converged platform that will support interactive television. Next Generation Network platforms such as the IP Multimedia Subsystem (IMS) support Quality of Service (QoS), fair charging and possible integration with other services for the deployment of IPTV services. IMS architecture supports the use of the Session Initiation Protocol (SIP) for session control and the Real Time Streaming Protocol (RTSP) for media control. This study aims to investigate video interactivity designs over the Internet using an evaluation framework to examine the performance of both SIP and RTSP protocols over the IMS over different access networks. It proposes a Three Layered Video Interactivity Framework (TLVIF) to reduce the video processing load on a server

AD39 Learning Design UML Profile

This document shows the UML Profile modelled for Learning Design, so it can be used as input for the Telcert Test System. The focus is not so much on the Learning Design as on the modelling of it