48 research outputs found

    Design and implementation of multicast listener discovery protocol on constrained devices

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    Para la aplicación y apoyo del uso de IPv6 en 6LoWPANs (Low-power Wireless Personal Area Networks), ha habido numerosas investigaciones y se han desarrollado protocolos y mecanismos estandarizados. Sin embargo para la comunicación multicast en estas redes, el tema esta aún bastante abierto a la investigación. La comunicación multicast permite conectar routers con hosts preseleccionados por grupos. La comunicación multicast es muy beneficiosa para aplicaciones con dispositivos con recursos limitados ya que ahorra energía y ancho de banda. A continuación mostramos posibles ejemplos de estas aplicaciones, la iluminación de un edificio organizada por plantas, una red de sensores de temperatura organizados por áreas y un largo número de aplicaciones basadas en la comunicación de un punto a varios puntos preseleccionados. El grupo de investigación de la universidad de Aalto (Finlandia) llamado MAMMoTH (Massive Scale Machine-to-Machine Service) tiene como uno de sus objetivos construir un protocolo multicast para dispositivos con recursos limitados. Para el desarrollo de este protocolo, es necesario un protocolo de encaminamiento multicast y un protocolo de gestión de grupos multicast. Este último, es el protocolo que he desarrollado como “research assistant” para mi proyecto final de carrera. En este proyecto final de carrera, se ha diseñado, implementado y evaluado el protocolo MLD para dispositivos con recursos limitados. MLD permite a un router IPv6 gestionar grupos multicast. No obstante, el uso de MLD en LoWPANs tiene varios problemas como la definición del area local, el tamaño de los paquete y la complejidad del comportamiento del router. El protocolo ha sido implementado en Contiki, un sistema operativo para desarrollar para el “Internet of Things”. Contiki permite conectar sistemas pequeños de poco coste con poca potencia a Internet. Hemos ampliado la pila TCP/IP de Contiki para respaldar MLD. El protocolo ha sido evaluado y analizado sobre un simulador en diferentes topologías para validar el funcionamiento. Del mismo modo, también se ha verificado que el tamaño del objeto creado no ocupaba más memoria de la disponible en los dispositivos Z1 Zolertia

    Analysis of IPv6 Neighbor Discovery for Mobile and Wireless Networks

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    The majority of the current 3GPP and M2M networks use or will use IPv6 for accessing the internet. These IPv6 networks use Neighbor Discovery as defined in RFC 4861 to identify their neighbors on the link and see if they are active. The increase in the complexity of wireless networks and introduction of battery operated devices sets forth notable challenges to certain assumptions in the RFC 4861. The RFC 4861 is more suited for wired networks and its implementation in wireless networks makes it more inefficient. This thesis work focuses on the energy efficient implementation of RFC 4861 using the protocols mentioned in draft-chakrabarti-nordmark-6man-efficient-nd-06. The draft suggests a method of registering all the nodes in the network to their default router, so that the router takes care of all the basic neighbor discovery functionalities without disturbing the battery operated devices which are in sleepy mode. Alongside the legacy Neighbor Discovery, the optimizations proposed by the draft are implemented, on a RADVD based router and an Ubuntu host, to reduce redundant multicast signaling in mobile networks. These optimizations are theoretically analyzed to check if the draft is beneficial for the scalability and transient nature of the wireless networks.Popular Science Report With the rise of Internet of Things (IoT) and Machine to Machine communication (M2M) based networks, more and more wireless devices are communicating to each other and hence there is a need for IPv6 (Internet Protocol version 6) addressing. This new type of addressing forces us to make some design changes in the existing protocols. Wireless devices are mostly mobile, battery operated (hence a power constraint exists) and can undergo several disconnections and reconnections while moving inside the network, whereas wired devices are less prone to network instabilities and almost always connected to a power source. Because of these differences, the protocols of wired devices are not always suitable for wireless networks. Still today’s wireless devices often use protocols that were designed for wired devices and tend to be inefficient. This thesis work deals with one such protocol called Internet Control Message Protocol (ICMP), which is widely used to send control messages across the network between different nodes. Neighbor Discovery Protocol (NDP) is a part of ICMPv6 that helps a node in the network identify its Neighbors on the other side of the link. Present generation wireless devices use the protocols defined in RFC 4861 (a common reference used by major communication companies while creating products) for Neighbor discovery. But this protocol proves to be inefficient by flooding the network with unwanted multicast control messages. Hence we analyze a modified version of the existing NDP against the legacy protocol. RFC 4861 based ‘legacy NDP’ works based on multicasting. Every IPv6 host is a part of several solicited node multicast groups. All nodes with the same last 24 IPv6 address bits belong to the same solicited node multicast group. NDP is also performed based on 4 major control message packets namely, Router Solicitation (RS), Router Advertisement (RA), Neighbor Solicitation (NS) and Neighbor Advertisement (NA). RA is the packet from the router which contains all the information about the network and the router. It is flooded periodically through an all node multicast group to all IPv6 nodes. When a node wants a particular router to send some information about the network immediately without waiting for periodic RAs, it sends an RS. Neighbor Advertisement is used by a node to send information about itself to other nodes in the network. Neighbor Solicitation, as name suggests, is used by a particular node to request for information about another node. Consider the case of a network with a host and a router, and a new node enters the network. It sends out RS to the all routers multicast group, and the router responds with an RA. The new host reads the information about the network and begins address configuration. Stateless Address Auto Configuration (SLAAC) is the most suitable method of address configuration for M2M networks. Hence according to SLAAC, the new host chooses an IP address and checks if the address has already been used by some other host. This process is called as Duplicate Address Detection (DAD) and is carried out by sending out NS for that chosen IP address at the solicited node multicast group address. This means that the new host asks information about a node with that IP address, which may or may not exist at all. If a reply comes, it means that there is a node using this address. If a reply does not come, then it is free to choose the address. The response NA in case of a duplicate address, will be broadcast to all IPv6 nodes. A NS-NA pair is also used to resolve each other’s IP addresses against their MAC addresses. One of the major reasons why this method seems to be inefficient is that current wireless devices are programmed to be in sleep modes when not in use. The flow of control messages to unrelated nodes (because of multicast) will only lead to disrupted sleep. Consider a host A in the network which is in sleep mode, and has an IP address aaaa::aaaa:aaaa:a. When a new host arrives and wants to register itself with an address of aaaa::baaa:aaaa:a, it sends out NS to the multicast group of A (because A has the same last 24 bits). When a packet reaches A, it wakes up from sleep mode, reads the message and identifies that this message was not destined to it. If there was another host in the group which used the same IP address, then host A will also receive another NA, which again is not of any use. Hence this protocol proves to be inefficient. The new proposed protocol works with an efficient implementation of the NDP. It introduces a concept of registering a host with a router. And the router sends out NS and NA instead of the host. Hence each router’s NCE will be the source of information for those hosts which are registered to that router. If a node will request for details about another host, the details will either be fetched from that router’s NCE or the NS will be forwarded to that particular host instead of being multicast. The router to whom the destination host is registered will then send NAs on behalf of its host. Hence in this protocol, the router performs more work and the host less, allowing the host to stay in sleep modes without any problems. The analysis of the two protocols begins with their implementation. We decided to test the working of the two protocols at two specific case scenarios: when several hosts join the network and when the channel links are unsteady. Both protocols were implemented and compared. The implementation of the legacy NDP began with a router and a host system. We used an Ubuntu PC (which generally works as a host) as a router. RADVD is an open source software that helps to generate RAs and Wireshark the software used to analyze packets in the network. To make a host work as a router, the following changes were made: 1. Turn on forwarding in the PC 2. Configure the router with a static IP address 3. Configure the interfaces and add corresponding routing information 4. Install RADVD and include all the network parameters in the config file 5. Turn on Wireshark 6. Turn on RADVD Once all these steps are done in order, the RADVD sends out periodic RAs that can be viewed on the Wireshark. When the host is connected to the network, the entire process of address configuration and DAD can be identified. When pinged, the address resolution process can also be verified. To implement the new protocol, we downloaded the source code of the open source RADVD from GitHub and change the packet formats of the RA, NS and NA. When the router works as a NEAR (Neighbor Discovery Efficiency Aware Router), the host has to understand that it should not use legacy NDP anymore and must act as an Efficiency Aware host (EAH). This information comes with the RA in the form of a flag. When this is done, the host sends an NS in the form of registration request. The details of the host go in the Address Resolution Option (ARO) of the NS. The router responds with an NA which is the acknowledgement for the registration request. Now the host can enter into sleep mode and the router will send control packets to it only when required. When the registration expires, a new registration process has to be setup or a de-registration process has to happen by setting the ARO option in the NS to 0. To implement the changes in the host side, we downloaded the source code for Linux from GitHub and led the decoder side. The process ends by making all the necessary code changes, recompiling a new Kernel and installing the new version of Linux on the hosts. However, the complete reprogramming of the kernel is not handled in this thesis work. But the entire plan for the programming and the rest of the implementation is included in this report. The theoretical analysis of the protocols is also included in this report. This report concludes with a general analysis of the whole protocol. The whole protocol which was completely decentralized has a certain degree of centralized control now. As with all systems, centralization introduces better control but there is always a problem of device failure which can completely collapse the system. The protocol also provides solutions for router failure and recovery and hence the system is a good compromise between centralized and decentralized systems. If properly implemented, there will be an increase in the network efficiency (inversely proportional to the number of control packets for every single data point). This thesis ends with the theoretical analysis. A proper implementation followed by a practical analysis would be a natural future amendment to the projec

    A Cross-System Approach for Multimedia Services with IP Multicast in 4G Networks

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    The increased demand for multimedia services by mobile end users in recent years have driven both Broadcast and Wireless Network operators to develop new systems and architectures for the deployment of such services. The proposed solutions are nonetheless limited either in terms of QoS or Capabilities to deliver new interactive services. This paper highlights strengths and drawbacks of the existing technologies in terms of QoS, Security and Mobility. In order to fill the gap between current solutions we propose a new architecture that builds itself on the synergies created by a heterogeneous network made of existing delivering technologies, such as 3GPP/MBMS and DVB, where services can be delivered to end-users in the most appropriate way for end-users and operators alike. A prototype implementation is further described.EU project - IST-2002- 506997 Daidalos I

    Experimental evaluation of an open source implementation of IPv6 GeoNetworking in VANETs

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    Conference is technically co-sponsored by IEEE Communications Society and co-organized by the Technical Sub-Committee on Vehicular Networks and Telematics (VNAT)International audienceISO TC204 and ETSI TC ITS are developing a set of standards for Cooperative ITS (Cooperative Intelligent transportation Systems) which will allow ITS stations i.e. vehicles, the road infrastructure and other peers reachable through the Internet to cooperate and exchange information with one another in order to enhance road safety, traffic efficiency and comfort for all road users. In situations where the exchange of information has to transit through the Internet, the use of IP, more specifically IPv6, is crucial and meets ITS needs for reliable and scalable communication capabilities in vehicular networks. An implementation of Cooperative ITS communication protocols is necessary to validate extensively the ETSI and ISO Coop- erative ITS standards. In this paper, we describe CarGeo6, an ongoing open-source implementation of the IPv6 GeoNetworking capabilities of the ITS station reference architecture based on the output of the GeoNet European Project. CarGeo6 combines IPv6 and GeoNetworking capabilities into a common protocol stack for the transmission of IPv6 packets into a given geographical area. This paper reports the validation process and the network performance evaluation of CarGeo6 as well as a comparison of these results with GeoNet results

    Accessing the Internet through Moving Networks

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    Poster at IST Mobile & Wireless Communications Summit 2007, Budapest, Hungary, 1-5 July 2007.The success of cellular communications networks shows the interest of users in mobility. Host mobility support in IP networks is a first step in the adaptation of these networks to the needs of users in this field. But, there exists also the need of supporting the movement of a complete network that changes its point of attachment to the fixed infrastructure. This paper describes the architecture designed in the EU DAIDALOS II project to provide Internet access through moving networks. The designed moving networks architecture support the following main features: Route Optimisation, Multicast traffic delivery, security and authentication integration, end-to-end QoS and interaction with Localised Mobility Management solutions.Publicad

    Monitoring multicast traffic in heterogeneous networks

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    Estágio realizado no INESC - Porto e orientado pelo Prof. Doutor Ricardo MorlaTese de mestrado integrado. Engenharia Electrotécnica e de Computadores - Major Telecomunicações. Faculdade de Engenharia. Universidade do Porto. 200

    How efficient is Efficient NDP?

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    In the following years we will experience a transition towards Internet Protocol version 6 (IPv6). The reason is the depletion of IPv4 address space due to the rapid increasing numbers of Internet of Things (IoT) devices connection. This transition however poses a problem, since the majority of these devices mostly are mobile and not connected to power source. Neighbor Discovery Protocol (NDP) defined in RFC 4861 is used in IPv6 networks, to manage the address configuration as well as the network prefix and maintain lists of all the neighbors connected to that network. However, this protocol does not work as good in wireless connected devices as in wired. The messages exchange in the network disrupts the sleep mode of the nodes resulting in lower battery time. Hence the energy efficiency of these devices is now something we should consider. To solve this problem, the Efficient NDP draft was introduced as one of the optimized methods. This thesis takes the previous theses of analysis and simulations of IPv6 Neighbor Discovery for wireless networks further, to explore the ND protocol in RFC 4861 (legacy NDP), and compare it to the Efficient NDP draft in terms of energy efficiency for the devices mentioned above. Several dynamic network cases are taken into analysis, and simulation scenarios for these cases are tested in OMNeT++. These simulation models follow the implementation process introduced in the protocols with consideration of network scalability, and present the result that the Efficient NDP has large improvement in saving multicast messages in ND process.In the real world, people need addresses to identify their locations. Similar to this, devices also need to have network labels which called IP addresses for identification and locating when they connect to the Internet. Internet Protocol version 4 (IPv4) is a protocol which introduces a 32-bits IP address format and popularly used in today’s networks. However, the increased number of devices connecting to the Internet has led to the depletion of available IPv4 addresses. IPv6 was introduced with more address space to solve IPv4 address exhaustion problem. But on the other hand, many existing protocols used in IPv4 have to be extended or redesigned to fit IPv6 networks. A network always contains many nodes (routers and hosts). A node recognizes other nodes in its located network as its neighbors. Discovering neighbor locations, gathering neighbor information and defining the communication methods between neighbors are the contents in IPv6 Neighbor Discovery Protocol (NDP). The legacy NDP was announced 10 years ago in RFC 4861. It relies on periodical multicast Internet Control Message Protocol version 6 (ICMPv6) control messages to maintain relationship between neighbors. Which means that these control messages are sent to all the members in a group. Although these messages are only relevant to a specific member in this group at most of time, other members also have to receive and process them. As we known, receiving and processing messages require power consumption. It is inefficient for nodes to handle these unnecessary messages frequently, especially for wireless devices. As wireless devices are always not connected to power supplies, power saving becomes an important point for their battery life. To solve the high power consumption problem in legacy NDP, a more efficient protocol the Efficient NDP was announced. This protocol introduces a registration mechanism for hosts with a router. In this mechanism, the router does not need to send periodical control messages to the hosts for asking their updates, but give a registration timer to each host. A host only has to wake up and send messages to the router when the timer is reached, and can keep in sleep mode for a long time. This can significantly reduce the power consumption. On the other hand, as the router functions as a registration point in the network, it has the knowledge of each node address information, so it can help hosts for handling address related issues with their neighbors. From analysis, we have already known that the Efficient NDP provides a good solution in power saving, comparing with the legacy NDP. But how efficient it can achieve? To answer this question, an evaluation is required. As today’s networks are always dynamic networks, nodes are able to enter, leave and change their locations in networks at any time, it is worth for us to analyze the performance of these two protocols in this environments. However, as implementing a real dynamic network environment is too complex, simulation becomes an ideal method for evaluation. Two scenarios were taken into analysis and simulations in this thesis, one is nodes entering and leaving a network scenario, and another is nodes losing connection to a network case in movement scenario. As network scalability is an important parameter for evaluation, simulation models were designed with different network sizes. The obtained results indicate that in both of these scenarios, the Efficient NDP can achieve very high messages saving percentages in large networks. On the other word, it provides a great power saving solution

    Development of a multicast routing protocol for low power and lossy networks

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    The Internet of things (IoT) is a new paradigm that has been gaining popularity in recent years. As the name "Internet of things" suggests, things surrounding us will be able to interact with each other and also connect to the Internet, thus forming a worldwide network of connected objects. The number of potential applications of this concept is huge and indudes various domains such as home environment, transportation, healthcare and so on. To enable the Internet of things, different technologies and standards have been proposed. Among them, the IP for Smart Objects (IPSO) alliance promotes the use of Internet Protocol (IP) as the network technology for IoT. The Internet Engineering Task Force (IETF), as part of its IoT related activities, has been working on using IPv6 to connect devices in low power wireless personal area networks (LoWPANs). The devices operating in LoWPANs are constrained on resources such as memory, processing power and sometimes energy (in case, they are operating on battery). Hence protocols designed for such networks have to consider the limitations of the devices. There has been considerable research done to design protocols that enable and support IPv6 in LoWPANs. However, there is not much effort in the area of multicast communication. There are various scenarios where efficient multicast communication would be beneficial. For example, consider a group of lights in a room that can be controlled by an actuator. In such scenarios, well designed multicast protocols would be useful in saving resources of the nodes. In this thesis, we design and implement a multicast routing protocol for low power and lossy networks. The protocol is implemented on Contiki OS, an operating system developed for the Internet of things. In addition, we test this protocol using Cooja, a cross-layer simulator developed for Contiki OS

    A Common API for Transparent Hybrid Multicast

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    Group communication services exist in a large variety of flavors and technical implementations at different protocol layers. Multicast data distribution is most efficiently performed on the lowest available layer, but a heterogeneous deployment status of multicast technologies throughout the Internet requires an adaptive service binding at runtime. Today, it is difficult to write an application that runs everywhere and at the same time makes use of the most efficient multicast service available in the network. Facing robustness requirements, developers are frequently forced to use a stable upper-layer protocol provided by the application itself. This document describes a common multicast API that is suitable for transparent communication in underlay and overlay and that grants access to the different flavors of multicast. It proposes an abstract naming scheme that uses multicast URIs, and it discusses mapping mechanisms between different namespaces and distribution technologies. Additionally, this document describes the application of this API for building gateways that interconnect current Multicast Domains throughout the Internet. It reports on an implementation of the programming Interface, including service middleware. This document is a product of the Scalable Adaptive Multicast (SAM) Research Group

    Mobilidade de emissores e receptores em redes com suporte de multicast

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    Mestrado em Engenharia Electrónica e TelecomunicaçõesEste trabalho de investigação pretende apresentar, desenvolver e avaliar uma nova solução para a mobilidade de terminais em redes IP com suporte Multicast. Tendo em conta que são cada vez mais frequentes aplicações multimédia, tais como, vídeo-conferências, IPTV, entre muitas outras, as quais requerem uma elevada largura de banda e penalizam a eficácia da rede, é necessário desenvolver trabalho nesta temática a qual se encontra ainda, nos nossos dias, pouco aprofundada. O IP Multicast consiste no envio de apenas um pacote de dados mesmo que essa informação seja pedida por vários receptores da rede. Para isso, baseiase no conceito de grupo. Os elementos da rede, que fazem parte da chamada árvore de distribuição desse grupo multicast, replicam o pacote de forma a enviar uma cópia do mesmo sempre que o caminho para os receptores divergir. Com o advento da tecnologia e tendo em conta as redes de próxima geração, verifica-se que estas são essencialmente baseadas no conceito de mobilidade. Por mobilidade entende-se a capacidade de um terminal se conectar a um outro elemento (Access Router) da rede. A solução apresentada pretende oferecer de forma eficiente e transparente suporte ao movimento dos terminais minimizando os tempos de disrupção associados. Efectuou-se uma análise às soluções existentes e tendo em conta a convergência das mesmas, para resolver problemas relacionados com mobilidade de terminais multicast, uma nova solução centrada em Agentbased é apresentada. A proposta apresentada foi testada recorrendo ao simulador NS2, demonstrando a eficiência e escalabilidade desta solução de mobilidade em redes multicast. ABSTRACT: This research work aims to produce, develop and evaluate a new solution to the mobility of terminals in IP Multicast networks. Since, multimedia applications, such as, video-conferences, IPTV, and many others, are, nowadays, more common and because these applications require a lot of bandwidth and reduce the network efficiency, it is necessary to work on this subject which is not, yet, very developed. IP Multicast allows sending only one data packet even if such information is requested by several receivers on the network. For that, it is based on the concept of group. The elements on the network, which are part of the multicast delivery tree for that group, replicate the packet, when the path to receivers differ, in order to send one copy for each one. With the advent of technology and taking into account next generation networks, we see that they are essentially based on the concept of mobility. The concept of mobility means the ability of a terminal to connect to another element (Access Router) on the network. The presented solution aims to efficiently and transparently support terminals movement minimizing the correspondent disruption time. Analyzing current solutions and taking into account their convergence, in order to solve multicast terminals mobility issues, a new Agent-based solution is presented. The proposal was tested using the simulator NS2, demonstrating the efficiency and scalability of this mobility solution in multicast networks
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