17 research outputs found

    A Telephony Gateway REgistration Protocol (TGREP)

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    Implementing a secured IMS-based Identity exchange

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    With the continuous development of telecommunications, networking and the ubiquitous computing the necessity of higher bandwidth and better quality of services is always one of the most important user requirements. In this background, IP Multimedia Subsystem (IMS) is becoming very important for the Next Generation Networking (NGN) and all-Internet Protocol (all-IP) infrastructure. This new tendency provides opportunities for new operators and service providers to enter the market and to be competitive. These developments will generate new challenges related to the user identity assurance. It will be more difficult to rely on the old paradigms of the static operator relationships guaranteeing end-to-end the identity of the users. In this case there is crucial need to find new mechanisms to provide to the end points assurance about the identity of their counterparts. In this work we implemented a solution that establishes a trust between two end points by taking advantage of IMS in a roaming scenario where the visited access network may not be entirely trustworthy. In essence, this means establishing an identity association so that the parties can have operator provided assurance regarding the used identities. This allows local trust decisions and does not rely on the existence of global Public Key Infrastructure (PKI). Concretely in this work we have modified the Session Initiation Protocol (SIP) “INVITE” messages by adding new SIP headers such as the identity and the signature of the SIP entities taking part in a multimedia conversation. Every SIP entity has to add its own identity and signature and also has to verify those of its counterparts in a typical SIP “INVITE” exchange. By this work we show that establishing this kind of identity association is feasible but some scalability issues have to be taken into account such as the time delay or the size of the new messages. In order to accomplish this master thesis work, we have used the Open Source IMS Core (OSIMS) platform developed by FOKUS, SailFin project as the Application Server (AS) and IMS Communicator as the IMS client. /Kir1

    Sip-rtsp Convergence: Rtsp-c

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    Tez (Yüksek Lisans) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 2008Thesis (M.Sc.) -- İstanbul Technical University, Institute of Science and Technology, 2008Bu çalışma ile SIP protokolü iletimde kullanılarak ve RTSP protokolü yetenekleri SIP mesaj gövdesine yerleştirilerek VOIP ağlarında yeni bir medya kontrol modeli öne sürülmüştür. RTSP-C olarak isimlendirilmiş olan bu yeni yakınlaşma modeli sadece SIP ve RTSP protokollerinin bir arada çalışmasını garantilemekle kalmamakta; aynı zamanda medya kontrol isteklerinin asıllanması ve oturum sunum bilgisi (SDP) alış verişindeki bazı açık noktalara çözüm getirmektedir. Bu yeni model RTSP protokolünün NAT geçirimie ait yöntemlere gereksinimini ortadan kaldırmakla beraber, SIP protokolünün NAT geçirim yöntemleri geçerliliğini korumaktadır. Bu modelin sağladığı asıl gelişme medya kontrolü bilgisi ve durum bilgisini SIP protokolüne açık hale getirmesidir. Bu sayede bu model medya yayınına dayalı yeni SIP servislerinin geliştirilmesine olanak sağlamaktadır. Bu proje kapsamında ortaya koyulan yeni modeli örneklendirmek amacıyla bir İsteğe Bağlı Görüntü Yayını (VoD) sistemi geliştirilmiştir. Bu uygulama ile RTSP-C yakınlaştırma modelinin çalışabilirliği doğrolanmıştır. Sonuçlar literatürdeki diğer örnekler ile karşılaştırıldığında modelin daha onceden belirlenen sorunlara uygun çözümleri sağladığı görülmüştür.In this study, using Session Initiation Protocol (SIP) as transport and placing Real Time Streaming Protocol (RTSP) capabilities in the SIP message body, a media control model has been introduced for Voice Over IP (VOIP) networks. This new convergence model does not only guarantee the interoperability of SIP and RTSP protocols but also resolve some open points on media control request authentication and session presentation (SDP) exchange. This new model is also valid for NAT Traversal methods applicable to SIP while it lifts the necessity of NAT Traversal methods for RTSP. The major advancement this model provides is: it makes the media control method/state information available to SIP. By doing that, this model enables the development of new streaming based SIP services. In this project content a Video on Demand (VoD) system is developped to instantiate the new convergence model. The implementation validated the operability of RTSP-C convergence model. The comparison of the results with other models on literature showed that the model provided adequate solutions on the pre-determined problems.Yüksek LisansM.Sc

    Proceedings of the 12th International Conference on Digital Preservation

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    The 12th International Conference on Digital Preservation (iPRES) was held on November 2-6, 2015 in Chapel Hill, North Carolina, USA. There were 327 delegates from 22 countries. The program included 12 long papers, 15 short papers, 33 posters, 3 demos, 6 workshops, 3 tutorials and 5 panels, as well as several interactive sessions and a Digital Preservation Showcase

    Proceedings of the 12th International Conference on Digital Preservation

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    The 12th International Conference on Digital Preservation (iPRES) was held on November 2-6, 2015 in Chapel Hill, North Carolina, USA. There were 327 delegates from 22 countries. The program included 12 long papers, 15 short papers, 33 posters, 3 demos, 6 workshops, 3 tutorials and 5 panels, as well as several interactive sessions and a Digital Preservation Showcase

    On the development of Voice over IP

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    This record of study documents the experience acquired during my internship at Sonus Networks, Inc. for the Doctor of Engineering Program. In this record of study, I have surveyed and analyzed the current standardization status of Voice over Internet Protocol (VoIP) security and proposed an Internet draft on secure retargeting and response identity. The draft provides a simple and comprehensive solution to the response identity, call recipient identity and intermediate server retargeting problems in the Session Initiation Protocol (SIP) call setup process. To support product line development and enable product evolution in the quickly growing VoIP market, I have proposed a generic development framework for SIP application servers. The common and open architecture of the framework supports multiple products development and facilitates integration of new service modules. The systematical reuse of proven software design and implementation enables companies to reduce the development cost and shorten the time-to-market. As the development and diffusion of VoIP can never be isolated from the social sphere, I have investigated the current status, influence and interaction of three most important factors: standardization, market forces and government regulation on the development and diffusion of VoIP. The worldwide deregulation and market privatization have caused the transition of the standards development model. This transition in turn influences the market diffusion. Other than standardization, market forces including customer needs, the revenue pressure on carriers and vendors, competitive and economic environment, social culture and regulation uncertainties create both threats and opportunities. I have examined market drivers and obstacles in the current VoIP adoption stage, analyzed current VoIP market players and their strategies, and predicted the direction of VoIP business. The regulation creates the macro environment in which VoIP develops and diffuses. I have explored modern telecommunications regulation principles based on which government makes decisions on most current issues, including 911 support, mergers and acquisitions, interconnection obligation and leasing rights, rate structure and universal service fees

    Representing Trunk Groups in tel/sip Uniform Resource Identifiers (URIs)

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    Integrating Context-Awareness in the IP Multimedia Subsystem for Enhanced Session Control and Service Provisioning Capabilities

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    The 3GPP-defined IP Multimedia Subsystem (IMS) is becoming the de-facto standard for IP-based multimedia communication services. It consists of an overlay control and service layer that is deployed on top of IP-based mobile and fixed networks. This layer encompasses a set of common functions (e.g. session control functions allowing the initiation/modification/termination of sessions) and service logics that are needed for the seamless provisioning of IP multimedia services to users, via different access technologies. As it continues to evolve, the IMS still faces several challenges including: the enabling of innovative and personalized services that would appeal to users and increase network operators' revenues; its interaction with other types of networks (e.g. wireless sensor networks) as means to enhance its capabilities; and the support of advanced QoS schemes that would manage the network resources in an efficient and adaptive manner. The context-awareness concept, which comes from the pervasive computing field, signifies the ability to use situational information (or context) in support to operations and decision making and for the provision of relevant services to the user. Context-awareness is considered to enhance users' experience and is seen as an enabler to adaptability and service personalization - two capabilities that could play important roles in telecommunication environments. This thesis focuses on the introduction of the context-awareness technology in the IMS, as means to enhance its session control and service provisioning capabilities. It starts by presenting the necessary background information, followed by a derivation of requirements and a review of the related work. To ensure the availability of contextual information within the network, we then propose an architecture for context information acquisition and management in the IMS. This architecture leverages and extends the 3GPP presence framework. Building on the capabilities of this architecture, we demonstrate how the managed information could be integrated in IMS operations, at the control and service levels. Showcasing control level integration, we propose a novel context-aware call differentiation framework as means to offer enhanced QoS support (for sessions/calls) in IMS-based networks. This framework enables the differentiation between different categories of calls at the IMS session control level, via dynamic and adaptive resource allocation, in addition to supporting a specialized charging model. Furthermore, we also propose a framework for enhanced IMS emergency communication services. This framework addresses the limitations of existing IP-based emergency solutions, by offering three main improvements: a QoS-enhanced emergency service; a context-aware personalized emergency service; and a conferencing-enhanced emergency service. We demonstrate the use of context awareness at the IMS service level using two new context-aware IMS applications. Finally, to validate our solutions and evaluate their performance, we build various proof-of-concept prototypes and OPNET simulation model

    Design and implementation aspects of open source next generation networks (NGN) test-bed software toolkits

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    Informations- und Kommunikationstechnologien bilden seit langem das immer wichtiger werdende Rückgrat der weltweiten Wirtschaft und Telekommunikation, in der speziell Telekommunikationsnetze und -dienste einen elementaren Anteil tragen. Durch die Konvergenz von Telekommunikations- und Internettechnologien hat sich die Telekommunikationslandschaft in der letzten Dekade drastisch verändert. Bislang geschlossene Telekommunikationsumgebungen haben sich imWandel zum sogenannten Next Generation Network (NGN) hinsichtlich unterstützter Zugangsnetztechnologien und angebotener multimedialer Anwendungen sowie der eingesetzten Protokolle und Dienste zu komplexen, hochdynamischen, Multi-Service Infrastrukturen gewandelt. Die Kontrollschicht solcher NGNs ist dabei von übergeordneter Bedeutung, da diese zwischen den Zugangsnetzen und den Anwendungen sitzt. Der Einsatz und die Optimierung des IP-Multimedia Subsystem (IMS) wurde in diesem Kontext Jahrelang erforscht und diskutiert und es repräsentiert heute die weltweit anerkannte Kontrollplattform für feste und mobile Telekommunikationsnetze. Die Forschung an Protokollen und Diensten in diesen NGN Umgebungen ist aufgrund der Konvergenz von Technologien, Anwendungen und Business Modellen sowie der hohen Dynamik aber kurzen Innovationszyklen hochkomplex. Der frühzeitigen Zugang zu herstellerunabhängigen – aber dicht an der Produktwelt angelehnten - Validierungsinfrastrukturen, sogenannten offenen Technologietest-beds, kurz Test-beds, ist daher für Forschungs- und Entwicklungsabteilungen unerlässlich Die vorliegende Dissertation beschreibt die umfangreiche Forschungsarbeit des Autors auf dem Gebiet der offenen NGN Test-beds über die letzten neun Jahre und konzentriert sich dabei auf Entwurf, Entwicklung und Bereitstellung des Open Source IMS Core Projekt, das seit Jahren die Grundlage für eine Vielzahl von NGN Test-beds und zahllose NGN Forschungs- und Entwicklungsprojekte im akademischen als auch Industrienahen Umfeld rund um den Globus darstellt. Dabei wird ein großer Schwerpunkt auf die Anforderungen hinsichtlich Flexibilität, Leistung, Funktionalitätsumfang und Interoperabilität, sowie elementare Designprinzipien von Test-bedwerkzeugen gelegt. Die Arbeit beschreibt und bewertet darüberhinaus den Einsatz von Open Source Prinzipien und veranschaulicht die Vorteile dieses Ansatzes hinsichtlich Einfluss und Nachhaltigkeit der Forschung anhand des Aufbaus einer globalen Open Source IMS Core (OpenIMSCore) Forschungs-Community. Außerdem veranschaulicht die Arbeit zum Ende die Wiederverwendbarkeit der wesentlichen angewendeten Designprinzipien an anderen maßgeblich durch den Autor entwickelten Test-bed Werkzeugen, insbesondere dem Open Evolved Packet Core (OpenEPC) für die nahtlose Integration verschiedener Breitbandnetztechnologien.Information and Communication Technologies provide for a long time already the backbone of telecommunication networks, such that communication services represent an elementary foundation of today’s globally connected economy. The telecommunication landscape has experienced dramatic transformations through the convergence of the Telecom and the Internet worlds. The previously closed telecommunication domain is currently transforming itself through the so-called NGN evolution into a highly dynamic multiservice infrastructure, supporting rich multimedia applications, as well as providing comprehensive support for various access technologies. The control layer of such NGNs is then of paramount importance, as representing the convergent mediator between access and services. The use and the optimization of the IP-Multimedia Subsystem (IMS) was researched and considered in this domain for many years now, such that today it represents the world-wide recognized control platform for fixed and mobile NGNs. Research on protocols and services for such NGN architectures, due to the convergence of technologies, applications and business models, as well as for enabling highly dynamic and short innovation cycles, is highly complex and requires early access to vendor independent - yet close to real life systems - validation environments, the so-called open technology test-beds. The present thesis describes the extensive research of the author over the last nine years in the field of open NGN test-beds. It focuses on the design, development and deployment of the Open Source IMS Core project, which represents since years the foundation of numerous NGN test-beds and countless NGN Research & Development projects in the academia as well as the industry domain around the globe. A major emphasis is given for ensuring flexibility, performance, reference functionality and inter-operability, as well as satisfying elementary design principles of such test-bed toolkits. The study also describes and evaluates the use of Open Source principles, highlighting the advantages of using it in regard to the creation, impact and sustainability of a global OpenIMSCore research community. Moreover, the work documents that the essential design principles and methodology employed can be reused in a generic way to create test-bed toolkits in other technology domains. This is shown by introducing the OpenEPC project, which provides for seamless integration of different mobile broadband technologies

    Preface

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