H-P2PSIP: Interconnection of P2PSIP domains for Global Multimedia Services based on a Hierarchical DHT Overlay Network

The IETF P2PSIP WG is currently standardising a protocol for distributed mul- timedia services combining the media session functionality of SIP and the decentralised distribution and localisation of resources in peer-to-peer networks. The current P2PSIP scenarios only consider the infrastructure for the connectivity inside a single domain. This paper proposes an extension of the current work to a hierarchical multi-domain scenario: a two level hierarchical peer-to-peer overlay architecture for the interconnection of different P2PSIP domains. The purpose is the creation of a global decentralised multimedia services in enterprises, ISPs or community networks. We present a study of the Routing Performance and Routing State in the particular case of a two-level Distributed Hash Table Hierarchy that uses Kademlia. The study is supported by an analytical model and its validation by a peer-to-peer simulator.En prens

Efficient service discovery in wide area networks

Living in an increasingly networked world, with an abundant number of services available to consumers, the consumer electronics market is enjoying a boom. The average consumer in the developed world may own several networked devices such as games consoles, mobile phones, PDAs, laptops and desktops, wireless picture frames and printers to name but a few. With this growing number of networked devices comes a growing demand for services, defined here as functions requested by a client and provided by a networked node. For example, a client may wish to download and share music or pictures, find and use printer services, or lookup information (e.g. train times, cinema bookings). It is notable that a significant proportion of networked devices are now mobile. Mobile devices introduce a new dynamic to the service discovery problem, such as lower battery and processing power and more expensive bandwidth. Device owners expect to access services not only in their immediate proximity, but further afield (e.g. in their homes and offices). Solving these problems is the focus of this research. This Thesis offers two alternative approaches to service discovery in Wide Area Networks (WANs). Firstly, a unique combination of the Session Initiation Protocol (SIP) and the OSGi middleware technology is presented to provide both mobility and service discovery capability in WANs. Through experimentation, this technique is shown to be successful where the number of operating domains is small, but it does not scale well. To address the issue of scalability, this Thesis proposes the use of Peer-to-Peer (P2P) service overlays as a medium for service discovery in WANs. To confirm that P2P overlays can in fact support service discovery, a technique to utilise the Distributed Hash Table (DHT) functionality of distributed systems is used to store and retrieve service advertisements. Through simulation, this is shown to be both a scalable and a flexible service discovery technique. However, the problems associated with P2P networks with respect to efficiency are well documented. In a novel approach to reduce messaging costs in P2P networks, multi-destination multicast is used. Two well known P2P overlays are extended using the Explicit Multi-Unicast (XCAST) protocol. The resulting analysis of this extension provides a strong argument for multiple P2P maintenance algorithms co-existing in a single P2P overlay to provide adaptable performance. A novel multi-tier P2P overlay system is presented, which is tailored for service rich mobile devices and which provides an efficient platform for service discovery

Istunnon aloitusprotokollaan pohjautuvat mobiilivertaisverkot

This work continues on my Master's Thesis work done between July 2005 and January 2006. In my Master's Thesis, we presented how a mobile peer-to-peer file-sharing application can be implemented using the Session Initiation Protocol (SIP) as the underlying signaling protocol. The main objective of this thesis is to evaluate what kind of special requirements mobile environment poses for peer-to-peer application design, and present how peer-to-peer based services can be efficiently realized in next-generation mobile networks by using SIP with some enhancements as the peer-to-peer signaling protocol. This thesis is divided into two parts. In the first part, we present different peer-to-peer architectures and search algorithms, and evaluate their suitability for mobile use. We also review some mobile peer-to-peer middleware and file-sharing applications. Then, in the second part, we present our hybrid mobile peer-to-peer architecture consisting of a Symbian based mobile client and a SIP Application Server based super-peer. Key findings of this thesis are that the mobile peer-to-peer application based on SIP signaling and hybrid peer-to-peer architecture is suitable for mobile use as it minimizes overhead in mobile nodes and allows mobile operator to have control on its users in multi-operator environment. Also, the performance of the application satisfies user requirements.Tämä työ on jatkoa diplomityölleni, joka tehtiin Heinäkuu 2005 – Tammikuu 2006 välisenä aikana. Diplomityössäni esitimme kuinka mobiilivertaisverkkosovellus voidaan toteuttaa käyttäen Session Initiation Protocol (SIP) protokollaa allaolevana signalointiprotokollana. Tämän työn päätavoite on selvittää, mitä erikoisvaatimuksia mobiiliympäristö vertaisverkkosovelluksen suunnittelulle asettaa sekä kuinka vertaisverkkopalveluita voidaan tehokkaasti toteuttaa seuraavan sukupolven mobiiliverkoissa käyttämällä laajennettua SIP protokollaa sovelluksen merkinantoprotokollana. Tämä työ on jaettu kahteen osaan. Ensimmäisessa osassa käsittelemme eri vertaisverkkoarkkitehtuureja ja hakualgoritmeja, sekä arvioimme näiden sopivuutta mobiilikäyttöön. Käymme myös läpi joitain mobiilivertaisverkkotiedostojako-ohjelmia sekä middleware-alustoja. Työn toisessa osassa esittelemme oman mobiilivertaisverkkoarkkitehtuurimme, joka koostuu Symbian mobiilisovelluksesta sekä SIP sovelluspalvelin super-peer solmusta. Tutkimuksen päälöydökset ovat seuraavat: SIP protokollaa käyttävä hybridi-vertaisverkkosovellus toimii hyvin matkapuhelinympäristössä, koska se minimoi puhelimeen kohdistuvan rasituksen ja tekee mahdolliseksi matkapuhelinoperaattorin hallita sovelluksen käyttäjiä myöskin monioperaattoriympäristössä. Tämän lisäksi ohjelmiston suorituskyky täyttää käytäjien sille asettamat vaatimukset

Exploratory study to explore the role of ICT in the process of knowledge management in an Indian business environment

In the 21st century and the emergence of a digital economy, knowledge and the knowledge base economy are rapidly growing. To effectively be able to understand the processes involved in the creating, managing and sharing of knowledge management in the business environment is critical to the success of an organization. This study builds on the previous research of the authors on the enablers of knowledge management by identifying the relationship between the enablers of knowledge management and the role played by information communication technologies (ICT) and ICT infrastructure in a business setting. This paper provides the findings of a survey collected from the four major Indian cities (Chennai, Coimbatore, Madurai and Villupuram) regarding their views and opinions about the enablers of knowledge management in business setting. A total of 80 organizations participated in the study with 100 participants in each city. The results show that ICT and ICT infrastructure can play a critical role in the creating, managing and sharing of knowledge in an Indian business environment

RELOAD/CoAP architecture with resource aggregation/disaggregation service

M2M communication is expected to occur at a global level and for this reason federations of device networks are also expected. In such large scale environments, a critical issue is how to discover the available resources in a scalable manner. For this purpose CoAP Usage for RELOAD, a generic self-organizing P2P overlay network service, has been proposed to be used as a lookup service, to store available resources and as a cache for sensor data. However, such approach alone does not allow building an aggregate resource hierarchy, a very relevant issue for an efficient organization of data in future IoT applications. Here we address this issue and propose an architecture incorporating a resource aggregation/disaggregation service

Data storage solutions for the federation of sensor networks

In the near future, most of our everyday devices will be accessible via some network and uniquely identified for interconnection over the Internet. This new paradigm, called Internet of Things (IoT), is already starting to influence our society and is now driving developments in many areas. There will be thousands, or even millions, of constrained devices that will be connected using standard protocols, such as Constrained Application Protocol (CoAP), that have been developed under certain specifications appropriate for this type of devices. In addition, there will be a need to interconnect networks of constrained devices in a reliable and scalable way, and federations of sensor networks using the Internet as a medium will be formed. To make the federation of geographically distributed CoAP based sensor networks possible, a CoAP Usage for REsource LOcation And Discovery (RELOAD) was recently proposed. RELOAD is a peer-to-peer (P2P) protocol that ensures an abstract storage and messaging service to its clients, and it relies on a set of cooperating peers that form a P2P overlay network for this purpose. This protocol allows to define so-called Usages for applications to work on top of this overlay network. The CoAP Usage for RELOAD is, therefore, a way for CoAP based devices to store their resources in a distributed P2P overlay. Although CoAP Usage for RELOAD is an important step towards the federation of sensor networks, in the particular case of IoT there will be consistency and efficiency problems. This happens because the resources of CoAP devices/Things can be in multiple data objects stored at the overlay network, called P2P resources. Thus, Thing resource updates can end up being consuming, as multiple P2P resources will have to be modified. Mechanisms to ensure consistency become, therefore, necessary. This thesis contributes to advances in the federation of sensor networks by proposing mechanisms for RELOAD/CoAP architectures that will allow consistency to be ensured. An overlay network service, required for such mechanisms to operate, is also proposed.Num futuro próximo, a maioria dos nossos dispositivos do dia-a-dia estarão acessíveis através de uma rede e serão identificados de forma única para poderem interligar-se através da Internet. Este novo paradigma, conhecido hoje por Internet das Coisas (IoT), já está a começar a influenciar a nossa sociedade e está agora a impulsionar desenvolvimentos em inúmeras áreas. Teremos milhares, ou mesmo milhões, de dispositivos restritos que utilizarão protocolos padrão que foram desenvolvidos de forma a cumprir determinadas especificações associadas a este tipo de dispositivos, especificações essas que têm a ver com o facto destes dispositivos terem normalmente restrições de memória, pouca capacidade de processamento e muitos possuirem limitações energéticas. Surgirá ainda a necessidade de interligar, de forma fiável e escalonável, redes de dispositivos restritos.(…

Robust P2P Live Streaming

Projecte fet en col.laboració amb la Fundació i2CATThe provisioning of robust real-time communication services (voice, video, etc.) or media contents through the Internet in a distributed manner is an important challenge, which will strongly influence in current and future Internet evolution. Aware of this, we are developing a project named Trilogy leaded by the i2CAT Foundation, which has as main pillar the study, development and evaluation of Peer-to-Peer (P2P) Live streaming architectures for the distribution of high-quality media contents. In this context, this work concretely covers media coding aspects and proposes the use of Multiple Description Coding (MDC) as a flexible solution for providing robust and scalable live streaming over P2P networks. This work describes current state of the art in media coding techniques and P2P streaming architectures, presents the implemented prototype as well as its simulation and validation results