Prospects of peer-to-peer SIP for mobile operators

Tämän diplomityön tarkoituksena on esitellä kehitteillä oleva Peer-to-Peer Session Initiation Protocol (P2PSIP), jonka avulla käyttäjät voivat itsenäisesti ja helposti luoda keskenään puhe- ja muita multimediayhteyksiä vertaisverkko-tekniikan avulla. Lisäksi tarkoituksena on arvioida P2PSIP protokollan vaikutuksia ja mahdollisuuksia mobiilioperaattoreille, joille sitä voidaan pitää uhkana. Tästä huolimatta, P2PSIP:n ei ole kuitenkaan tarkoitus korvata nykyisiä puhelinverkkoja. Työn alussa esittelemme SIP:n ja vertaisverkkojen (Peer-to-Peer) periaatteet, joihin P2PSIP-protokollan on suunniteltu perustuvan. SIP mahdollistaa multimedia-istuntojen luomisen, sulkemisen ja muokkaamisen verkossa, mutta sen monipuolinen käyttö vaatii keskitettyjen palvelimien käyttöä. Vertaisverkon avulla käyttäjät voivat suorittaa keskitettyjen palvelimien tehtävät keskenään hajautetusti. Tällöin voidaan ylläpitää laajojakin verkkoja tehokkaasti ilman palvelimista aiheutuvia ylläpito-kustannuksia. Mobiilioperaattorit ovat haasteellisen tilanteen edessä, koska teleliikennemaailma on muuttumassa yhä avoimemmaksi. Tällöin operaattoreiden asiakkaille aukeaa mahdollisuuksia käyttää kilpailevia Internet-palveluja (kuten Skype) helpommin ja tulevaisuudessa myös itse muodostamaan kommunikointiverkkoja P2PSIP:n avulla. Tutkimukset osoittavat, että näistä uhista huolimatta myös operaattorit pystyvät näkemään P2PSIP:n mahdollisuutena mukautumisessa nopeasti muuttuvan teleliikennemaailman haasteisiin. Nämä mahdollisuudet sisältävät operaattorin oman verkon optimoinnin lisäksi vaihtoehtoisten ja monipuolisempien palveluiden tarjoamisen asiakkailleen edullisesti. Täytyy kuitenkin muistaa, että näiden mahdollisuuksien toteuttamisten vaikutusten ei tulisi olla ristiriidassa operaattorin muiden palveluiden kanssa. Lisäksi tulisi muistaa, että tällä hetkellä keskeneräisen P2PSIP-standardin lopullinen luonne ja ominaisuudet voivat muuttaa sen vaikutuksia.The purpose of this thesis is to present the Peer-to-Peer Session Initiation Protocol (P2PSIP) being developed. In addition, the purpose of this thesis is to evaluate the impacts and prospects of P2PSIP to mobile operators, to whom it can be regarded as a threat. In P2PSIP, users can independently and easily establish voice and other multimedia connections using peer-to-peer (P2P) networking. However, P2PSIP is not meant to replace the existing telephony networks of the operators. We start by introducing the principles of SIP and P2P networking that the P2PSIP is intended to use. SIP enables to establish, terminate and modify multimedia sessions, but its versatile exploitation requires using centralized servers. By using P2P networking, users can decentralize the functions of centralized servers by performing them among themselves. This enables to maintain large and robust networks without maintenance costs resulted of running such centralized servers. Telecommunications market is transforming to a more open environment, where mobile operators and other service providers are challenged to adapt to the upcoming changes. Subscribers have easier access to rivalling Internet-services (such as Skype) and in future they can form their own communication communities by using P2PSIP. The results show that despite of these threats, telecom operators can find potential from P2PSIP in concurrence in adaptation to the challenges of the rapidly changing telecom environment. These potential roles include optimization of the network of the operator, but as well roles to provide alternative and more versatile services to their subscribers at low cost. However, the usage of P2PSIP should not conflict with the other services of the operator. Also, as P2PSIP is still under development, its final nature and features may change its impacts and prospects

An interoperable and secure architecture for internet-scale decentralized personal communication

Interpersonal network communications, including Voice over IP (VoIP) and Instant Messaging (IM), are increasingly popular communications tools. However, systems to date have generally adopted a client-server model, requiring complex centralized infrastructure, or have not adhered to any VoIP or IM standard. Many deployment scenarios either require no central equipment, or due to unique properties of the deployment, are limited or rendered unattractive by central servers. to address these scenarios, we present a solution based on the Session Initiation Protocol (SIP) standard, utilizing a decentralized Peer-to-Peer (P2P) mechanism to distribute data. Our new approach, P2PSIP, enables users to communicate with minimal or no centralized servers, while providing secure, real-time, authenticated communications comparable in security and performance to centralized solutions.;We present two complete protocol descriptions and system designs. The first, the SOSIMPLE/dSIP protocol, is a P2P-over-SIP solution, utilizing SIP both for the transport of P2P messages and personal communications, yielding an interoperable, single-stack solution for P2P communications. The RELOAD protocol is a binary P2P protocol, designed for use in a SIP-using-P2P architecture where an existing SIP application is modified to use an additional, binary RELOAD stack to distribute user information without need for a central server.;To meet the unique security needs of a fully decentralized communications system, we propose an enrollment-time certificate authority model that provides asserted identity and strong P2P and user-level security. In this model, a centralized server is contacted only at enrollment time. No run-time connections to the servers are required.;Additionally, we show that traditional P2P message routing mechanisms are inappropriate for P2PSIP. The existing mechanisms are generally optimized for file sharing and neglect critical practical elements of the open Internet --- namely link-level security and asymmetric connectivity caused by Network Address Translators (NATs). In response to these shortcomings, we introduce a new message routing paradigm, Adaptive Routing (AR), and using both analytical models and simulation show that AR significantly improves message routing performance for P2PSIP systems.;Our work has led to the creation of a new research topic within the P2P and interpersonal communications communities, P2PSIP. Our seminal publications have provided the impetus for subsequent P2PSIP publications, for the listing of P2PSIP as a topic in conference calls for papers, and for the formation of a new working group in the Internet Engineering Task Force (IETF), directed to develop an open Internet standard for P2PSIP

Implementación y pruebas de REsource LOcation And Discovery (RELOAD) Parser and Encoder

El ampliamente utilizado paradigma cliente/servidor está siendo complementado e incluso reemplazado por otros planteamientos de tipo Peer-to-Peer (P2P). Las redes P2P ofrecen un sistema descentralizado de distribución de la información, son más estables, y representan una solución al problema de la escalabilidad. Al mismo tiempo, el Session Initiation Protocol (SIP), un protocolo de señalización diseñado inicialmente para arquitecturas de tipo ciente/servidor, ha sido ampliamente adoptado para servicios de comunicación tipo Voice-over-IP (VoIP). El actual proceso de estandarización llevado a cabo por el Peer-to-Peer Session Initiation Protocol (P2PSIP) Working Group del IETF se está acercando al desarrollo de aplicaciones que puedan utilizar tecnologías P2P junto con SIP. RELOAD es un protocolo P2P de señalización, que está todavía en desarrollo. RELOAD trabaja en entornos en los que existen Network Address Translators (NATs) o firewalls. RELOAD soporta diferentes aplicaciones y proporciona un marco de seguridad, también permite el uso de diversos algoritmos para las Distributed Hash Tables (DHTs) mediante los llamados "topology plugins". Esta tesis tiene como objetivos la implementación de un codificador y decodificador para mensajes de RELOAD, y el análisis de su rendimiento. Para este último punto se implementará un programa de prueba ejecutable en un teléfono móvil y en un servidor para la simulación de una red RELOAD. ________________________________________The widely used classic client/server paradigm is being complemented and sometimes replaced by current Peer-to-Peer (P2P) approaches. P2P networks offer decentralized distribution of information, are more stable, and represent a solution to the problem of scalability. At the same time the Session Initiation Protocol (SIP), a signalling protocol initially designed for client/server architectures, has been widely adopted for Voice-over-IP (VoIP) communication. The current standardization process of the Peer-to-Peer Session Initiation Protocol (P2PSIP) working group of the IETF is moving towards the development of applications that can use both P2P and Session Initiation Protocol (SIP) technologies in conjuntion. RELOAD is a P2P signalling protocol, which is still under development. RELOAD works in environments where there are Network Address Translators (NATs) or firewalls. RELOAD can support various applications and provides a security frameworks. RELOAD also allows the use of various Distributed Hash Table (DHT) algorithms in the form of topology plugins. This thesis aims at implementing a parser and encoder for RELOAD messages, and analyzing its performance by implementing a test program that will run on a mobile phone and on a server simulating a RELOAD overlay network.Ingeniería Técnica en Informática de Gestió

Integrating Wireless Sensor Networks and Mobile Ad-hoc NETworks for enhanced value-added services

In some situations where the standard telecommunication infrastructure is not available, Mobile Ad hoc NETworks (MANETs) can be deployed to provide the required communication. These networks are established "on the fly" without a need for prior communication organization and are composed of autonomous mobile devices, such as cell phones, PDAs or laptops. In similar conditions, such as in emergency response operations, integrating MANETs and Wireless Sensor Networks (WSNs) can notably enhance the MANET participant's end-user experience. WSNs sense and aggregate ambient information, such as physiological, environmental or physical data related to a nearby phenomenon. The integration, which provides end-user availability to WSN required information, is feasible via gateways. However, when the ambient information collected by WSNs is intended for applications residing in MANETs, centralized and fixed gateways are not practicably feasible. This is mainly due to ad-hoc nature, lack of centralized control and constraints on the end-user devices that are used in MANETs. These devices are usually limited in power and capacity and cannot host centralized gateways. In this thesis we exploit the integration of WSN and MANET in order to provide novel value-added services which enhance the end-user experience of MANET participants. Motivating scenarios are introduced, background information is presented, requirements are derived and the state of the art regarding the integration of WSN with existing networks, including MANETs, is evaluated. Based on the evaluation, none of the existing solutions satisfies all of our derived requirements. Therefore, we propose an overall two-level overlay architecture to integrate WSNs (with mobile sinks) and MANETs. This architecture is based on the distributed gateway and applications which form the P2P overlays. Overlays are application-layer networks which are created on top of the exiting MANET. To interconnect gateway and application overlays we derive corresponding requirements and evaluate the existing approaches. Since none of these approaches fulfills all of our requirements, we propose protocols, mechanisms and design corresponding modules for the interconnection of overlays. Finally we refine our overall architecture based on the interconnection aspects. As a proof of concept, we implement a prototype for the inter-overlay information exchange. This implementation is based on SIP extensions and uses two existing P2P middlewares. We also simulate our prototype using Oversim simulation tool and collect experimental results. Based on these results, we can see that our architecture is a valid and promising approach for interconnecting different P2P overlays and can be deployed to provide the overall solution for WSN and MANET integrated system

Prototyping a peer-to-peer session initiation protocol user agent

The Session Initiation Protocol (SIP) has in recent years become a popular protocol for the exchange of text, voice and video over IP networks. This thesis proposes the use of a class of structured peer to peer protocols - commonly known as Distributed Hash Tables (DHTs) - to provide a SIP overlay with services such as end-point location management and message relay, in the absence of traditional, centralised resources such as SIP proxies and registrars. A peer-to-peer layer named OverCord, which allows the interaction with any specific DHT protocol via the use of appropriate plug-ins, was designed, implemented and tested. This layer was then incorporated into a SIP user agent distributed by NIST (National Institute of Standards and Technology, USA). The modified user agent is capable of reliably establishing text, audio and video communication with similarly modified agents (peers) as well as conventional, centralized SIP overlays

Reducing Internet Latency : A Survey of Techniques and their Merit

Bob Briscoe, Anna Brunstrom, Andreas Petlund, David Hayes, David Ros, Ing-Jyh Tsang, Stein Gjessing, Gorry Fairhurst, Carsten Griwodz, Michael WelzlPeer reviewedPreprin

An Overlay Gateway for the Integration of IP Multimedia Subsystem and Mobile Sink Based-Wireless Sensor Networks

RÉSUMÉ D'une part les Réseaux de Capteurs (WSN par ses sigles en anglais) constituent un domaine de recherche qui a reçu beaucoup d'attention de la part de la communauté scientifique grâce à ses avantages en différents domaines. Chaque réseau est généralement conçu à partir de périphériques de petite taille appelés capteurs qui peuvent capter, effectuer des calculs et communiquer entre eux. De plus, inclure des stations de base mobiles dans les réseaux de capteurs sans fils s'est avéré utile dans une large gamme de scénarios puisque ces derniers permettent d'améliorer la durée de vie globale du réseau et d'augmenter la capacité de transmission de données. D'autre part, le sous-système IP Multimédia (IMS) vise à fournir un accès aux réseaux cellulaires à l'ensemble des services Internet. Il s'agit d'une surcouche de contrôle implantée sur une couche IP dont les objectifs sont de fournir et maintenir une qualité de service (QoS) donnée, un schéma de chargement équitable et des services intégrés; le tout en utilisant des interfaces standards. Combiner les fonctionnalités d‟IMS et l‟ensemble d'informations contextuelles capturées par les stations de base des réseaux de capteurs sans fils ouvre la porte à une nouvelle gamme de services multimédias. Cette dissertation propose une architecture de surcouche pour l'intégration des IMS avec les réseaux de capteurs sans fils. Le service "présence" sert de point d'entrée au domaine des IMS. La passerelle, qui constitue le coeur de notre architecture, est une couche de recouvrement construite sur les mêmes téléphones mobiles qui agissent également en tant que canaux mobiles, publicateurs / écouteurs de présence et périphériques utilisateurs. ----------ABSTRACT On one hand, Wireless Sensor Networks (WSNs) are a research area that has been gaining attention from the research community. They are made up of small scale devices called sensors that can sense, compute and communicate. Moreover, including mobile sinks in WSNs has shown to be useful in a wide range of scenarios since they can improve the overall network lifetime and increase data capacity. On the other hand, the IP Multimedia Subsystem (IMS) aims to provide cellular access to all Internet services. It is an overlay control layer on top of an IP layer whose goals is based in provisioning of Quality of Service (QoS), a fair charging scheme and integrated services through standard interfaces. Combining the capabilities of IMS with the rich set of contextual information captured by mobile sink WSNs opens the door to a wide range of novel multimedia services. This dissertation proposes an overlay architecture for the integration of IMS with mobile sink-based WSN. The Presence service is used as entry point to the IMS world. The gateway which is the heart of our architecture is an overlay built on top of the very same mobile phones that act as mobile sinks, presence publishers / watchers, and end-user devices