Analysis of relod.net, a basic implementation of the RELOAD protocol for peer-to-peer networks

Actas de: XI Jornadas de Ingeniería Telemática (JITEL 2013) celebradas en Granada, 28-30 Octubre 2013. La web del evento es: http://dtstc.ugr.es/jitel2013/#The P2PSIP Working Group is chartered to develop protocols and mechanisms for the use of SIP in distributed environments, thus minimizing the need for centralized servers. Under this premise, the RELOAD protocol was created, whose design was generalized to accept other applications with similar requirements, and which is currently in process of standardization by the IETF. In this paper, we present a basic implementation and an analysis of this protocol proposed standard, given the great interest displayed in recent years by the scientific and business community in issues related to peerto- peer networks. Later, we conduct several experiments in order to validate its correct operation in real scenarios and provide feedback in relation with the current specificationThis research was supported in part by the Comunidad de Madrid grant S-2009/TIC-1468 (MEDIANET project).Publicad

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

A Data Annotation Architecture for Semantic Applications in Virtualized Wireless Sensor Networks

Wireless Sensor Networks (WSNs) have become very popular and are being used in many application domains (e.g. smart cities, security, gaming and agriculture). Virtualized WSNs allow the same WSN to be shared by multiple applications. Semantic applications are situation-aware and can potentially play a critical role in virtualized WSNs. However, provisioning them in such settings remains a challenge. The key reason is that semantic applications provisioning mandates data annotation. Unfortunately it is no easy task to annotate data collected in virtualized WSNs. This paper proposes a data annotation architecture for semantic applications in virtualized heterogeneous WSNs. The architecture uses overlays as the cornerstone, and we have built a prototype in the cloud environment using Google App Engine. The early performance measurements are also presented.Comment: This paper has been accepted for presentation in main technical session of 14th IFIP/IEEE Symposium on Integrated Network and Service Management (IM 2015) to be held on 11-15 May, 2015, Ottawa, Canad

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.(…

Applying low discrepancy sequences for node-ID assignment in P2PSIP

The IETF P2PSIP Working Group is currently designing a standard overlay protocol, named RELOAD, that employs a centralized node identifier (node-id) assignment for security reasons. Given this scenario, we propose the utilization of a Low Discrepancy Sequence (LDS) for the assignment of node-ids in the P2PSIP architecture. We perform an analytical and simulation study considering a Chord DHT that demonstrates that using a LDS-based node-id assignment guarantees a fair distribution of the node's zone of responsibility, even in high churn scenarios. Previous studies have shown that a fairer distribution of the zones of responsibility sizes leads to a fairer distribution of the storage and routing load. Therefore we conclude that the proposed LDS node-id assignment provides these features without adding any extra overhead.This work has been partially supported by the EU through the FP7 TREND Project (257740), the Spanish Government through the T2C2 project (TIN2008-06739-C04-01), and the Regional Government of Madrid through the MEDIANET project (S-2009/TIC- 1468).Publicad

IETF standardization in the field of the Internet of Things (IoT): a survey

Smart embedded objects will become an important part of what is called the Internet of Things. However, the integration of embedded devices into the Internet introduces several challenges, since many of the existing Internet technologies and protocols were not designed for this class of devices. In the past few years, there have been many efforts to enable the extension of Internet technologies to constrained devices. Initially, this resulted in proprietary protocols and architectures. Later, the integration of constrained devices into the Internet was embraced by IETF, moving towards standardized IP-based protocols. In this paper, we will briefly review the history of integrating constrained devices into the Internet, followed by an extensive overview of IETF standardization work in the 6LoWPAN, ROLL and CoRE working groups. This is complemented with a broad overview of related research results that illustrate how this work can be extended or used to tackle other problems and with a discussion on open issues and challenges. As such the aim of this paper is twofold: apart from giving readers solid insights in IETF standardization work on the Internet of Things, it also aims to encourage readers to further explore the world of Internet-connected objects, pointing to future research opportunities

A Model to Quantify the Success of a Sybil Attack Targeting RELOAD/Chord Resources

The Sybil attack is one of the most harmful security threats for distributed hash tables (DHTs). This attack is not only a theoretical one, but it has been spotted "in the wild", and even performed by researchers themselves to demonstrate its feasibility. In this letter we analyse the Sybil attack whose objective is that the targeted resource cannot be accessed by any user of a Chord DHT, by replacing all the replica nodes that store it with sybils. In particular, we propose a simple, yet complete model that provides the number of random node-IDs that an attacker would need to generate in order to succeed with certain probability. Therefore, our model enables to quantify the cost of performing a Sybil resource attack on RELOAD/Chord DHTs more accurately than previous works, and thus establishes the basis to measure the effectiveness of different solutions proposed in the literature to prevent or mitigate Sybil attacks.This work has been partially supported by the EU FP7 TREND project (257740), the Spanish T2C2 project (TIN2008-06739-C04-01) and the Madrid MEDIANET project (S-2009/TIC-1468).European Community's Seventh Framework ProgramPublicad

Hybrid CoAP-based resource discovery for the Internet of Things

Enabling automatic, efficient and scalable discovery of the resources provided by constrained low-power sensor and actuator networks is an important element to empower the transformation towards the Internet of Things (IoT). To this end, many centralized and distributed resource discovery approaches have been investigated. Clearly, each approach has its own motivations, advantages and drawbacks. In this article, we present a hybrid centralized/distributed resource discovery solution aiming to get the most out of both approaches. The proposed architecture employs the well-known Constrained Application Protocol (CoAP) and features a number of interesting discovery characteristics including scalability, time and cost efficiency, and adaptability. Using such a solution, network nodes can automatically and rapidly detect the presence of Resource Directories (RDs), via a proactive RD discovery mechanism, and perform discovery tasks through them. Nodes may, alternatively, fall back automatically to efficient fully-distributed discovery operations achieved through Trickle-enabled, CoAP-based technics. The effectiveness of the proposed architecture has been demonstrated by formal analysis and experimental evaluations on dedicated IoT platforms