47 research outputs found
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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
State-of-the-Art Multihoming Protocols and Support for Android
Il traguardo più importante per la connettività wireless del futuro sarà sfruttare appieno le potenzialità offerte da tutte le interfacce di rete dei dispositivi mobili. Per questo motivo con ogni probabilità il multihoming sarà un requisito obbligatorio per quelle applicazioni che puntano a fornire la migliore esperienza utente nel loro utilizzo. Sinteticamente è possibile definire il multihoming come quel processo complesso per cui un end-host o un end-site ha molteplici punti di aggancio alla rete. Nella pratica, tuttavia, il multihoming si è rivelato difficile da implementare e ancor di più da ottimizzare.
Ad oggi infatti, il multihoming è lontano dall’essere considerato una feature standard nel network deployment nonostante anni di ricerche e di sviluppo nel settore, poiché il relativo supporto da parte dei protocolli è quasi sempre del tutto inadeguato.
Naturalmente anche per Android in quanto piattaforma mobile più usata al mondo, è di fondamentale importanza supportare il multihoming per ampliare lo spettro delle funzionalità offerte ai propri utenti. Dunque alla luce di ciò, in questa tesi espongo lo stato dell’arte del supporto al multihoming in Android mettendo a confronto diversi protocolli di rete e testando la soluzione che sembra essere in assoluto la più promettente: LISP.
Esaminato lo stato dell’arte dei protocolli con supporto al multihoming e l’architettura software di LISPmob per Android, l’obiettivo operativo principale di questa ricerca è duplice: a) testare il roaming seamless tra le varie interfacce di rete di un dispositivo Android, il che è appunto uno degli obiettivi del multihoming, attraverso LISPmob; e b) effettuare un ampio numero di test al fine di ottenere attraverso dati sperimentali alcuni importanti parametri relativi alle performance di LISP per capire quanto è realistica la possibilità da parte dell’utente finale di usarlo come efficace soluzione multihoming
Measuring Effectiveness of Address Schemes for AS-level Graphs
This dissertation presents measures of efficiency and locality for Internet addressing schemes.
Historically speaking, many issues, faced by the Internet, have been solved just in time, to make the Internet just work~\cite{justWork}. Consensus, however, has been reached that today\u27s Internet routing and addressing system is facing serious scaling problems: multi-homing which causes finer granularity of routing policies and finer control to realize various traffic engineering requirements, an increased demand for provider-independent prefix allocations which injects unaggregatable prefixes into the Default Free Zone (DFZ) routing table, and ever-increasing Internet user population and mobile edge devices. As a result, the DFZ routing table is again growing at an exponential rate.
Hierarchical, topology-based addressing has long been considered crucial to routing and forwarding scalability. Recently, however, a number of research efforts are considering alternatives to this traditional approach. With the goal of informing such research, we investigated the efficiency of address assignment in the existing (IPv4) Internet. In particular, we ask the question: ``how can we measure the locality of an address scheme given an input AS-level graph?\u27\u27
To do so, we first define a notion of efficiency or locality based on the average number of bit-hops required to advertize all prefixes in the Internet. In order to quantify how far from ``optimal the current Internet is, we assign prefixes to ASes ``from scratch in a manner that preserves observed semantics, using three increasingly strict definitions of equivalence.
Next we propose another metric that in some sense quantifies the ``efficiency of the labeling and is independent of forwarding/routing mechanisms. We validate the effectiveness of the metric by applying it to a series of address schemes with increasing randomness given an input AS-level graph. After that we apply the metric to the current Internet address scheme across years and compare the results with those of compact routing schemes
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
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Towards a reliable seamless mobility support in heterogeneous IP networks
This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.Next Generation networks (3G and beyond) are evolving towards all IP based systems with the aim to provide global coverage. For Mobility in IP based networks, Mobile IPv6 is considered as a standard by both industry and research community, but this mobility protocol has some reliability issues. There are a number of elements that can interrupt the communication between Mobile Node (MN) and Corresponding Node (CN), however the scope of this research is limited to the following issues only:
• Reliability of Mobility Protocol
• Home Agent Management
• Handovers
• Path failures between MN and CN
First entity that can disrupt Mobile IPv6 based communication is the Mobility Anchor point itself, i.e. Home Agent. Reliability of Home Agent is addressed first because if this mobility agent is not reliable there would be no reliability of mobile communication. Next scenario where mobile communication can get disrupted is created by MN itself and it is due to its mobility. When a MN moves around, at some point it will be out of range of its active base station and at the same time it may enter the coverage area of another base station. In such a situation, the MN should perform a handover, which is a very slow process. This handover delay is reduced by introducing a “make before break” style handover in IP network. Another situation in which the Mobile IPv6 based communication can fail is when there is a path failure between MN and CN. This situation can be addressed by utilizing multiple interfaces of MN at the same time. One such protocol which can utilize multiple interfaces is SHIM6 but it was not designed to work on mobile node. It was designed for core networks but after some modification in the protocol , it can be deployed on mobile nodes.
In this thesis, these issues related to reliability of IPv6 based mobile communication have been addressed