A Survey on Handover Management in Mobility Architectures

This work presents a comprehensive and structured taxonomy of available techniques for managing the handover process in mobility architectures. Representative works from the existing literature have been divided into appropriate categories, based on their ability to support horizontal handovers, vertical handovers and multihoming. We describe approaches designed to work on the current Internet (i.e. IPv4-based networks), as well as those that have been devised for the "future" Internet (e.g. IPv6-based networks and extensions). Quantitative measures and qualitative indicators are also presented and used to evaluate and compare the examined approaches. This critical review provides some valuable guidelines and suggestions for designing and developing mobility architectures, including some practical expedients (e.g. those required in the current Internet environment), aimed to cope with the presence of NAT/firewalls and to provide support to legacy systems and several communication protocols working at the application layer

DCCP Simultaneous-Open Technique to Facilitate NAT/Middlebox Traversal

https://datatracker.ietf.org/doc/rfc5595/Publisher PD

An interoperable and secure architecture for internet-scale decentralized personal communication

Interpersonal network communications, including Voice over IP (VoIP) and Instant Messaging (IM), are increasingly popular communications tools. However, systems to date have generally adopted a client-server model, requiring complex centralized infrastructure, or have not adhered to any VoIP or IM standard. Many deployment scenarios either require no central equipment, or due to unique properties of the deployment, are limited or rendered unattractive by central servers. to address these scenarios, we present a solution based on the Session Initiation Protocol (SIP) standard, utilizing a decentralized Peer-to-Peer (P2P) mechanism to distribute data. Our new approach, P2PSIP, enables users to communicate with minimal or no centralized servers, while providing secure, real-time, authenticated communications comparable in security and performance to centralized solutions.;We present two complete protocol descriptions and system designs. The first, the SOSIMPLE/dSIP protocol, is a P2P-over-SIP solution, utilizing SIP both for the transport of P2P messages and personal communications, yielding an interoperable, single-stack solution for P2P communications. The RELOAD protocol is a binary P2P protocol, designed for use in a SIP-using-P2P architecture where an existing SIP application is modified to use an additional, binary RELOAD stack to distribute user information without need for a central server.;To meet the unique security needs of a fully decentralized communications system, we propose an enrollment-time certificate authority model that provides asserted identity and strong P2P and user-level security. In this model, a centralized server is contacted only at enrollment time. No run-time connections to the servers are required.;Additionally, we show that traditional P2P message routing mechanisms are inappropriate for P2PSIP. The existing mechanisms are generally optimized for file sharing and neglect critical practical elements of the open Internet --- namely link-level security and asymmetric connectivity caused by Network Address Translators (NATs). In response to these shortcomings, we introduce a new message routing paradigm, Adaptive Routing (AR), and using both analytical models and simulation show that AR significantly improves message routing performance for P2PSIP systems.;Our work has led to the creation of a new research topic within the P2P and interpersonal communications communities, P2PSIP. Our seminal publications have provided the impetus for subsequent P2PSIP publications, for the listing of P2PSIP as a topic in conference calls for papers, and for the formation of a new working group in the Internet Engineering Task Force (IETF), directed to develop an open Internet standard for P2PSIP

Secure VoIP Performance Measurement

This project presents a mechanism for instrumentation of secure VoIP calls. The experiments were run under different network conditions and security systems. VoIP services such as Google Talk, Express Talk and Skype were under test. The project allowed analysis of the voice quality of the VoIP services based on the Mean Opinion Score (MOS) values generated by Perceptual valuation of Speech Quality (PESQ). The quality of the audio streams produced were subjected to end-to-end delay, jitter, packet loss and extra processing in the networking hardware and end devices due to Internetworking Layer security or Transport Layer security implementations. The MOS values were mapped to Perceptual Evaluation of Speech Quality for wideband (PESQ-WB) scores. From these PESQ-WB scores, the graphs of the mean of 10 runs and box and whisker plots for each parameter were drawn. Analysis on the graphs was performed in order to deduce the quality of each VoIP service. The E-model was used to predict the network readiness and Common vulnerability Scoring System (CVSS) was used to predict the network vulnerabilities. The project also provided the mechanism to measure the throughput for each test case. The overall performance of each VoIP service was determined by PESQ-WB scores, CVSS scores and the throughput. The experiment demonstrated the relationship among VoIP performance, VoIP security and VoIP service type. The experiment also suggested that, when compared to an unsecure IPIP tunnel, Internetworking Layer security like IPSec ESP or Transport Layer security like OpenVPN TLS would improve a VoIP security by reducing the vulnerabilities of the media part of the VoIP signal. Morever, adding a security layer has little impact on the VoIP voice quality

Multi-layer traffic control for wireless networks

Le reti Wireless LAN, così come definite dallo standard IEEE 802.11, garantiscono connettività senza fili nei cosiddetti “hot-spot” (aeroporti, hotel, etc.), nei campus universitari, nelle intranet aziendali e nelle abitazioni. In tali scenari, le WLAN sono denotate come “ad infrastruttura” nel senso che la copertura della rete è basata sulla presenza di un “Access Point” che fornisce alle stazioni mobili l’accesso alla rete cablata. Esiste un ulteriore approccio (chiamato “ad-hoc”) in cui le stazioni mobili appartenenti alla WLAN comunicano tra di loro senza l’ausilio dell’Access Point. Le Wireless LAN tipicamente sono connesse alla rete di trasporto (che essa sia Internet o una Intranet aziendale) usando un’infrastruttura cablata. Le reti wireless Mesh ad infrastruttura (WIMN) rappresentano un’alternativa valida e meno costosa alla classica infrastruttura cablata. A testimonianza di quanto appena affermato vi è la comparsa e la crescita sul mercato di diverse aziende specializzate nella fornitura di infrastrutture di trasporto wireless e il lancio di varie attività di standardizzazione (tra cui spicca il gruppo 802.11s). La facilità di utilizzo, di messa in opera di una rete wireless e i costi veramente ridotti hanno rappresentato fattori critici per lo straordinario successo di tale tecnologia. Di conseguenza possiamo affermare che la tecnologia wireless ha modificato lo stile di vita degli utenti, il modo di lavorare, il modo di passare il tempo libero (video conferenze, scambio foto, condivisione di brani musicali, giochi in rete, messaggistica istantanea ecc.). D’altro canto, lo sforzo per garantire lo sviluppo di reti capaci di supportare servizi dati ubiqui a velocità di trasferimento elevate è strettamente legato a numerose sfide tecniche tra cui: il supporto per l’handover tra differenti tecnologie (WLAN/3G), la certezza di accesso e autenticazione sicure, la fatturazione e l’accounting unificati, la garanzia di QoS ecc. L’attività di ricerca svolta nell’arco del Dottorato si è focalizzata sulla definizione di meccanismi multi-layer per il controllo del traffico in reti wireless. In particolare, nuove soluzioni di controllo del traffico sono state realizzate a differenti livelli della pila protocollare (dallo strato data-link allo strato applicativo) in modo da fornire: funzionalità avanzate (autenticazione sicura, differenziazione di servizio, handover trasparente) e livelli soddisfacenti di Qualità del Servizio. La maggior parte delle soluzioni proposte in questo lavoro di tesi sono state implementate in test-bed reali. Questo lavoro riporta i risultati della mia attività di ricerca ed è organizzato nel seguente modo: ogni capitolo presenta, ad uno specifico strato della pila protocollare, un meccanismo di controllo del traffico con l’obiettivo di risolvere le problematiche presentate precedentemente. I Capitoli 1 e 2 fanno riferimento allo strato di Trasporto ed investigano il problema del mantenimento della fairness per le connessioni TCP. L’unfairness TCP conduce ad una significativa degradazione delle performance implicando livelli non soddisfacenti di QoS. Questi capitoli descrivono l’attività di ricerca in cui ho impiegato il maggior impegno durante gli studi del dottorato. Nel capitolo 1 viene presentato uno studio simulativo delle problematiche di unfairness TCP e vengono introdotti due possibili soluzioni basate su rate-control. Nel Capitolo 2 viene derivato un modello analitico per la fairness TCP e si propone uno strumento per la personalizzazione delle politiche di fairness. Il capitolo 3 si focalizza sullo strato Applicativo e riporta diverse soluzioni di controllo del traffico in grado di garantire autenticazione sicura in scenari di roaming tra provider wireless. Queste soluzioni rappresentano parte integrante del framework UniWireless, un testbed nazionale sviluppato nell’ambito del progetto TWELVE. Il capitolo 4 descrive, nuovamente a strato Applicativo, una soluzione (basata su SIP) per la gestione della mobilità degli utenti in scenari di rete eterogenei ovvero quando diverse tecnologie di accesso radio sono presenti (802.11/WiFi, Bluetooth, 2.5G/3G). Infine il Capitolo 5 fa riferimento allo strato Data-Link presentando uno studio preliminare di un approccio per il routing e il load-balancing in reti Mesh infrastrutturate.Wireless LANs, as they have been defined by the IEEE 802.11 standard, are shared media enabling connectivity in the so-called “hot-spots” (airports, hotel lounges, etc.), university campuses, enterprise intranets, as well as “in-home” for home internet access. With reference to the above scenarios, WLANs are commonly denoted as “infra-structured” in the sense that WLAN coverage is based on “Access Points” which provide the mobile stations with access to the wired network. In addition to this approach, there exists also an “ad-hoc” mode to organize WLANs where mobile stations talk to each other without the need of Access Points. Wireless LANs are typically connected to the wired backbones (Internet or corporate intranets) using a wired infrastructure. Wireless Infrastructure Mesh Networks (WIMN) may represent a viable and cost-effective alternative to this traditional wired approach. This is witnessed by the emergence and growth of many companies specialized in the provisioning of wireless infrastructure solutions, as well as the launch of standardization activities (such as 802.11s). The easiness of deploying and using a wireless network, and the low deployment costs have been critical factors in the extraordinary success of such technology. As a logical consequence, the wireless technology has allowed end users being connected everywhere – every time and it has changed several things in people’s lifestyle, such as the way people work, or how they live their leisure time (videoconferencing, instant photo or music sharing, network gaming, etc.). On the other side, the effort to develop networks capable of supporting ubiquitous data services with very high data rates in strategic locations is linked with many technical challenges including seamless vertical handovers across WLAN and 3G radio technologies, security, 3G-based authentication, unified accounting and billing, consistent QoS and service provisioning, etc. My PhD research activity have been focused on multi-layer traffic control for Wireless LANs. In particular, specific new traffic control solutions have been designed at different layers of the protocol stack (from the link layer to the application layer) in order to guarantee i) advanced features (secure authentication, service differentiation, seamless handover) and ii) satisfactory level of perceived QoS. Most of the proposed solutions have been also implemented in real testbeds. This dissertation presents the results of my research activity and is organized as follows: each Chapter presents, at a specific layer of the protocol stack, a traffic control mechanism in order to address the introduced above issues. Chapter 1 and Charter 2 refer to the Transport Layer, and they investigate the problem of maintaining fairness for TCP connections. TCP unfairness may result in significant degradation of performance leading to users perceiving unsatisfactory Quality of Service. These Chapters describe the research activity in which I spent the most significant effort. Chapter 1 proposes a simulative study of the TCP fairness issues and two different solutions based on Rate Control mechanism. Chapter 2 illustrates an analytical model of the TCP fairness and derives a framework allowing wireless network providers to customize fairness policies. Chapter 3 focuses on the Application Layer and it presents new traffic control solutions able to guarantee secure authentication in wireless inter-provider roaming scenarios. These solutions are an integral part of the UniWireless framework, a nationwide distributed Open Access testbed that has been jointly realized by different research units within the TWELVE national project. Chapter 4 describes again an Application Layer solution, based on Session Initiation Protocol to manage user mobility and provide seamless mobile multimedia services in a heterogeneous scenario where different radio access technologies are used (802.11/WiFi, Bluetooth, 2.5G/3G networks). Finally Chapter 5 refers to the Data Link Layer and presents a preliminary study of a general approach for routing and load balancing in Wireless Infrastructure Mesh Network. The key idea is to dynamically select routes among a set of slowly changing alternative network paths, where paths are created through the reuse of classical 802.1Q multiple spanning tree mechanisms

DSL-based triple-play services

This research examines the triple play service based on the ADSL technology. The voice over IP will be checked and combined with the internet data by two monitoring programs in order to examine the performance that this service offers and then will be compared with the usual method of internet connection.This research examines the triple play service based on the ADSL technology. The voice over IP will be checked and combined with the internet data by two monitoring programs in order to examine the performance that this service offers and then will be compared with the usual method of internet connection.

ACUTA eNews July 2013 Vol. 42, No. 7

In this Issue... 1 Let\u27s Talk about Data Security 2 ACUTA Reaches Out to Local Schools 2 Regulatory Webinar on Section 255 2 Welcome, Owen West 3 20 Universities Form SIP Steering Committee i 3ACUTA Discount for SIP Certification 4 Info Links 4 Annual Dues Reminder Mailed July 1 5 loyn/RCSvs. webRTC: Solving Directory Services 6 Do You ROCKZi? 6 Mark Your Calendar for Fall Seminar 7 Board Report 8 Welcome New Members 8 Check It Ou