Heterogeneous Access: Survey and Design Considerations

As voice, multimedia, and data services are converging to IP, there is a need for a new networking architecture to support future innovations and applications. Users are consuming Internet services from multiple devices that have multiple network interfaces such as Wi-Fi, LTE, Bluetooth, and possibly wired LAN. Such diverse network connectivity can be used to increase both reliability and performance by running applications over multiple links, sequentially for seamless user experience, or in parallel for bandwidth and performance enhancements. The existing networking stack, however, offers almost no support for intelligently exploiting such network, device, and location diversity. In this work, we survey recently proposed protocols and architectures that enable heterogeneous networking support. Upon evaluation, we abstract common design patterns and propose a unified networking architecture that makes better use of a heterogeneous dynamic environment, both in terms of networks and devices. The architecture enables mobile nodes to make intelligent decisions about how and when to use each or a combination of networks, based on access policies. With this new architecture, we envision a shift from current applications, which support a single network, location, and device at a time to applications that can support multiple networks, multiple locations, and multiple devices

Use of locator/identifier separation to improve the future internet routing system

The Internet evolved from its early days of being a small research network to become a critical infrastructure many organizations and individuals rely on. One dimension of this evolution is the continuous growth of the number of participants in the network, far beyond what the initial designers had in mind. While it does work today, it is widely believed that the current design of the global routing system cannot scale to accommodate future challenges. In 2006 an Internet Architecture Board (IAB) workshop was held to develop a shared understanding of the Internet routing system scalability issues faced by the large backbone operators. The participants documented in RFC 4984 their belief that "routing scalability is the most important problem facing the Internet today and must be solved." A potential solution to the routing scalability problem is ending the semantic overloading of Internet addresses, by separating node location from identity. Several proposals exist to apply this idea to current Internet addressing, among which the Locator/Identifier Separation Protocol (LISP) is the only one already being shipped in production routers. Separating locators from identifiers results in another level of indirection, and introduces a new problem: how to determine location, when the identity is known. The first part of our work analyzes existing proposals for systems that map identifiers to locators and proposes an alternative system, within the LISP ecosystem. We created a large-scale Internet topology simulator and used it to compare the performance of three mapping systems: LISP-DHT, LISP+ALT and the proposed LISP-TREE. We analyzed and contrasted their architectural properties as well. The monitoring projects that supplied Internet routing table growth data over a large timespan inspired us to create LISPmon, a monitoring platform aimed at collecting, storing and presenting data gathered from the LISP pilot network, early in the deployment of the LISP protocol. The project web site and collected data is publicly available and will assist researchers in studying the evolution of the LISP mapping system. We also document how the newly introduced LISP network elements fit into the current Internet, advantages and disadvantages of different deployment options, and how the proposed transition mechanism scenarios could affect the evolution of the global routing system. This work is currently available as an active Internet Engineering Task Force (IETF) Internet Draft. The second part looks at the problem of efficient one-to-many communications, assuming a routing system that implements the above mentioned locator/identifier split paradigm. We propose a network layer protocol for efficient live streaming. It is incrementally deployable, with changes required only in the same border routers that should be upgraded to support locator/identifier separation. Our proof-of-concept Linux kernel implementation shows the feasibility of the protocol, and our comparison to popular peer-to-peer live streaming systems indicates important savings in inter-domain traffic. We believe LISP has considerable potential of getting adopted, and an important aspect of this work is how it might contribute towards a better mapping system design, by showing the weaknesses of current favorites and proposing alternatives. The presented results are an important step forward in addressing the routing scalability problem described in RFC 4984, and improving the delivery of live streaming video over the Internet

Multihoming with ILNP in FreeBSD

Multihoming allows nodes to be multiply connected to the network. It forms the basis of features which can improve network responsiveness and robustness; e.g. load balancing and fail-over, which can be considered as a choice between network locations. However, IP today assumes that IP addresses specify both network location and node identity. Therefore, these features must be implemented at routers. This dissertation considers an alternative based on the multihoming approach of the Identifier Locator Network Protocol (ILNP). ILNP is one of many proposals for a split between network location and node identity. However, unlike other proposals, ILNP removes the use of IP addresses as they are used today. To date, ILNP has not been implemented within an operating system stack. I produce the first implementation of ILNP in FreeBSD, based on a superset of IPv6 – ILNPv6 – and demonstrate a key feature of ILNP: multihoming as a first class function of the operating system, rather than being implemented as a routing function as it is today. To evaluate the multihoming capability, I demonstrate one important application of multihoming – load distribution – at three levels of network hierarchy including individual hosts, a singleton Site Border Router (SBR), and a novel, dynamically instantiated, distributed SBR (dSBR). For each level, I present empirical results from a hardware testbed; metrics include latency, throughput, loss and reordering. I compare performance with unmodified IPv6 and NPTv6. Finally, I evaluate the feasibility of dSBR-ILNPv6 as an alternative to existing multihoming approaches, based on measurements of the dSBR’s responsiveness to changes in site connectivity. We find that multihoming can be implemented by individual hosts and/or SBRs, without requiring additional routing state as is the case today, and without any significant additional load or overhead compared to unicast IPv6

Tecnologías wireless y movilidad en IPv4/IPv6

Sin lugar a dudas estamos en un hito particular en la historia de Internet y de las redes en general que es la irrupción de las redes inalámbricas y la proliferación de dispositivos inalámbricos con la posibilidad de integrarse a diversos tipos de redes cada vez en un número mayor. Fue algo muy difícil de prever que un experimento allá por 1979, que consistía en utilizar enlaces infrarrojos para crear una red local en una fábrica y publicados en el volumen 67 de los Proceeding del IEEE, llegara a considerarse como el punto de partida de esta tecnología. Las aplicaciones de las redes inalámbricas se multiplican diariamente. De momento van a crear una nueva forma de usar la información, pues ésta estará al alcance de todos a través de Internet en cualquier lugar. Algo también muy importante, la ubicuidad que las acompaña ya ha producido cambios de hábito en los usuarios, en el trabajo y en la educación. Muy pronto todos aquellos dispositivos con los que hoy contamos evolucionarán hacia aquellos en los cuales estarían reunidas las funciones de teléfono móvil, agenda, terminal de vídeo, reproductor multimedia, equipo portátil, etc. En un futuro también cercano la conjugación de las redes Mesh, con las redes inalámbricas y las redes Grid podría llevar a cabo al nacimiento de nuevas formas de computación que permitan realizar cálculos inimaginables hasta el momento. Los autores nos sumergimos en la aventura de esta publicación pensando que con este humilde aporte lograremos dar a conocer las bases de esta tecnología, su estado actual y su evolución y para que cuando estemos sentados a la mesa de un café accediendo a una página web o chateando con nuestros amigos disfrutemos más el momento que sólo el conocimiento de lo que ocurre nos brinda.XV Escuela Internacional de Informática, realizada durante el XVII Congreso Argentino de Ciencia de la Computación (CACIC 2011).Red de Universidades con Carreras en Informática (RedUNCI