Addressing Devices in Mobile Networks

Mobiilterminalide arengust tingitud vhenenud energiakulu, sisseehitatud sensorite kasutusvimalus, suurenenud ttlusjudlus ja mlumaht vimaldavad mobiilide laialdase kasutuse erinevates domeenides nagu mobiilne sotsiaalvrgustik, mobiilne pilvandmettlus ja Internet of Things (IoT). Selleks, et antud seadmeid oleks vimalik edukalt informatsiooni pakkumise ja ttlemise vahenditena kasutada, on vaja identitseerimiseks ja adresseerimiseks lesandele kohaseid vahendeid, mis vimaldaksid ligipsu seadmetele ja teenustele ka vljaspool mobiilsidevrku. Enamuse ajast, kui kasutajad kasutavad Internetiga hendamiseks mobiilivrke, paiknevad kasutajate seadmed tulemride ja vrguaadressi translaatorite (NAT ehk Network Address Translator) taga, mis takistavad otsese henduse loomist. Kasutajate hendamist mobiilsetes vrkudes on aastaid phjalikult uuritud ja selle tulemusena on leitud mitmeid lahendusi. IP-aadress, mis on levinuim adresseerimise mehhanism Internetis, on htlasi laialdaselt kasutusel mobiilivrkudes (3G/4G), kuid sellel on omad piirangud: ajutine kttesaadavus, piiratud kasutus ainult mobiilioperaatorite vrkudes ja vrguaadresside tlkimine (NAT). Nende piirangute krvaldamiseks pakume vlja mned teistsugused lhenemised: Session Initiation Protocol (SIP), Rendezvous serveri toel toimiv UDP/TCP Hole Punching ja UDP/TCP Relaying. Neidsaab kasutada erinevate mobiilsidevrkude tpide puhul. Kesolevas magistrits ksitletakse praktilist paigaldust, testide tulemusi ja iga lhenemise nrku ning tugevaid klgi.The emergence of mobile terminals with enhanced features like high processing power, more memory, inbuilt sensors, low power consumption, etc. have led to their extensive usage in different domains like mobile social networking, mobile cloud and Internet of Things (IoT). However, to successfully utilize these devices as information providing/processing entities, we need proper means of identification and addressing, so that the devices and their offered data/services are accessible also from outside the mobile network. But most of the times, when the peers connecting to the internet through cellular networks, peer devices locate behind the common components like firewalls and Network Address Translators (NATs) that prevent establishing direct connections. Setting up connection between peers in mobile networks has been examined extensively over the years and there are several solutions one can conceive. However, the most popular and widely used addressing mechanism for internet, IP address, is also being extensively used in mobile data networks (3G/4G) but ends up with barriers like their temporarily availability, known only within the mobile operators network, Network Address Translation (NAT) etc. To address such kind of limitations we proposed few different approaches such as Session Initiation Protocol (SIP), UDP/TCP hole punching with help from the Rendezvous server and UDP/TCP Relaying those can be applied to different types of mobile networks. In this thesis we discuss practical implementation, test results and evaluation of strengths and limitations of each approach

Structured Peer-to-Peer Overlays for NATed Churn Intensive Networks

The wide-spread coverage and ubiquitous presence of mobile networks has propelled the usage and adoption of mobile phones to an unprecedented level around the globe. The computing capabilities of these mobile phones have improved considerably, supporting a vast range of third party applications. Simultaneously, Peer-to-Peer (P2P) overlay networks have experienced a tremendous growth in terms of usage as well as popularity in recent years particularly in fixed wired networks. In particular, Distributed Hash Table (DHT) based Structured P2P overlay networks offer major advantages to users of mobile devices and networks such as scalable, fault tolerant and self-managing infrastructure which does not exhibit single points of failure. Integrating P2P overlays on the mobile network seems a logical progression; considering the popularities of both technologies. However, it imposes several challenges that need to be handled, such as the limited hardware capabilities of mobile phones and churn (i.e. the frequent join and leave of nodes within a network) intensive mobile networks offering limited yet expensive bandwidth availability. This thesis investigates the feasibility of extending P2P to mobile networks so that users can take advantage of both these technologies: P2P and mobile networks. This thesis utilises OverSim, a P2P simulator, to experiment with the performance of various P2P overlays, considering high churn and bandwidth consumption which are the two most crucial constraints of mobile networks. The experiment results show that Kademlia and EpiChord are the two most appropriate P2P overlays that could be implemented in mobile networks. Furthermore, Network Address Translation (NAT) is a major barrier to the adoption of P2P overlays in mobile networks. Integrating NAT traversal approaches with P2P overlays is a crucial step for P2P overlays to operate successfully on mobile networks. This thesis presents a general approach of NAT traversal for ring based overlays without the use of a single dedicated server which is then implemented in OverSim. Several experiments have been performed under NATs to determine the suitability of the chosen P2P overlays under NATed environments. The results show that the performance of these overlays is comparable in terms of successful lookups in both NATed and non-NATed environments; with Kademlia and EpiChord exhibiting the best performance. The presence of NATs and also the level of churn in a network influence the routing techniques used in P2P overlays. Recursive routing is more resilient to IP connectivity restrictions posed by NATs but not very robust in high churn environments, whereas iterative routing is more suitable to high churn networks, but difficult to use in NATed environments. Kademlia supports both these routing schemes whereas EpiChord only supports the iterating routing. This undermines the usefulness of EpiChord in NATed environments. In order to harness the advantages of both routing schemes, this thesis presents an adaptive routing scheme, called Churn Aware Routing Protocol (ChARP), combining recursive and iterative lookups where nodes can switch between recursive and iterative routing depending on their lifetimes. The proposed approach has been implemented in OverSim and several experiments have been carried out. The experiment results indicate an improved performance which in turn validates the applicability and suitability of ChARP in NATed environments

De-ossifying the Internet Transport Layer : A Survey and Future Perspectives

ACKNOWLEDGMENT The authors would like to thank the anonymous reviewers for their useful suggestions and comments.Peer reviewedPublisher PD

Agent-based approach for cross-subnet communication

Projecte realitzat mitjançant programa de mobilitat. TECHNISCHE UNIVERSITÄT BERLIN. FAKULTÄT IV - ELEKTROTECHNIK UND INFORMATIKThe establishment of point-to-point connections between hosts behind NAT boxes have been always a problem due to the problem with the private IP addresses and NAT rewalls. To solve this problem, there are di erent techniques to make possible that hosts behind NAT boxes can establish a point-to-point connection rounding NAT rewalls and using solutions to exchange their IPs. The goal of this thesis is to present an implementation of a communication protocol which establishes a communication between agents that are behind NAT boxes avoiding all the problems that could occur during the communication, such as duplicated IP addresses or host unreachable errors and introduce to the reader some related work about NAT traversal. There is also in this thesis a little introduction to the existing techniques used to round a NAT rewall and the explanation of why we use NAT boxes even though they sometimes are a problem

Global connectivity architecture of mobile personal devices

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2008.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Includes bibliographical references (p. 193-207).The Internet's architecture, designed in the days of large, stationary computers tended by technically savvy and accountable administrators, fails to meet the demands of the emerging ubiquitous computing era. Nontechnical users now routinely own multiple personal devices, many of them mobile, and need to share information securely among them using interactive, delay-sensitive applications.Unmanaged Internet Architecture (UIA) is a novel, incrementally deployable network architecture for modern personal devices, which reconsiders three architectural cornerstones: naming, routing, and transport. UIA augments the Internet's global name system with a personal name system, enabling users to build personal administrative groups easily and intuitively, to establish secure bindings between his devices and with other users' devices, and to name his devices and his friends much like using a cell phone's address book. To connect personal devices reliably, even while mobile, behind NATs or firewalls, or connected via isolated ad hoc networks, UIA gives each device a persistent, location-independent identity, and builds an overlay routing service atop IP to resolve and route among these identities. Finally, to support today's interactive applications built using concurrent transactions and delay-sensitive media streams, UIA introduces a new structured stream transport abstraction, which solves the efficiency and responsiveness problems of TCP streams and the functionality limitations of UDP datagrams. Preliminary protocol designs and implementations demonstrate UIA's features and benefits. A personal naming prototype supports easy and portable group management, allowing use of personal names alongside global names in unmodified Internet applications. A prototype overlay router leverages the naming layer's social network to provide efficient ad hoc connectivity in restricted but important common-case scenarios.(cont) Simulations of more general routing protocols--one inspired by distributed hash tables, one based on recent compact routing theory--explore promising generalizations to UIA's overlay routing. A library-based prototype of UIA's structured stream transport enables incremental deployment in either OS infrastructure or applications, and demonstrates the responsiveness benefits of the new transport abstraction via dynamic prioritization of interactive web downloads. Finally, an exposition and experimental evaluation of NAT traversal techniques provides insight into routing optimizations useful in UIA and elsewhere.by Bryan Alexander Ford.Ph.D

A Multi-perspective Analysis of Carrier-Grade NAT Deployment

As ISPs face IPv4 address scarcity they increasingly turn to network address translation (NAT) to accommodate the address needs of their customers. Recently, ISPs have moved beyond employing NATs only directly at individual customers and instead begun deploying Carrier-Grade NATs (CGNs) to apply address translation to many independent and disparate endpoints spanning physical locations, a phenomenon that so far has received little in the way of empirical assessment. In this work we present a broad and systematic study of the deployment and behavior of these middleboxes. We develop a methodology to detect the existence of hosts behind CGNs by extracting non-routable IP addresses from peer lists we obtain by crawling the BitTorrent DHT. We complement this approach with improvements to our Netalyzr troubleshooting service, enabling us to determine a range of indicators of CGN presence as well as detailed insights into key properties of CGNs. Combining the two data sources we illustrate the scope of CGN deployment on today's Internet, and report on characteristics of commonly deployed CGNs and their effect on end users

Study and implementation of a real time online football game for mobile devices

The main goal of this project is extracting an optimized system to do a sensible application to delay loses and jitter in a wireless environment. This system will be used in a football game for mobile devices with maximum two players per game

Mass Adoption of NATs: Survey and experiments on carrier-grade NATs

In recent times, the prevalence of home NATs and the widespread implementation of Carrier-Grade NATs have posed significant challenges to various applications, particularly those relying on Peer-to-Peer communication. This paper addresses these issues by conducting a thorough review of related literature and exploring potential techniques to mitigate the problems. The literature review focuses on the disruptive effects of home NATs and CGNATs on application performance. Additionally, the study examines existing approaches used to alleviate these disruptions. Furthermore, this paper presents a comprehensive guide on how to puncture a NAT and facilitate direct communication between two peers behind any type of NAT. The techniques outlined in the guide are rigorously tested using a simple application running the IPv8 network overlay, along with their built-in NAT penetration procedures. To evaluate the effectiveness of the proposed techniques, 5G communication is established between two phones using four different Dutch telephone carriers. The results indicate successful cross-connectivity with three out of the four carriers tested, showcasing the practical applicability of the suggested methods.Comment: 12 pages, 9 figure