Treatment-Based Classi?cation in Residential Wireless Access Points

IEEE 802.11 wireless access points (APs) act as the central communication hub inside homes, connecting all networked devices to the Internet. Home users run a variety of network applications with diverse Quality-of-Service requirements (QoS) through their APs. However, wireless APs are often the bottleneck in residential networks as broadband connection speeds keep increasing. Because of the lack of QoS support and complicated configuration procedures in most off-the-shelf APs, users can experience QoS degradation with their wireless networks, especially when multiple applications are running concurrently. This dissertation presents CATNAP, Classification And Treatment iN an AP , to provide better QoS support for various applications over residential wireless networks, especially timely delivery for real-time applications and high throughput for download-based applications. CATNAP consists of three major components: supporting functions, classifiers, and treatment modules. The supporting functions collect necessary flow level statistics and feed it into the CATNAP classifiers. Then, the CATNAP classifiers categorize flows along three-dimensions: response-based/non-response-based, interactive/non-interactive, and greedy/non-greedy. Each CATNAP traffic category can be directly mapped to one of the following treatments: push/delay, limited advertised window size/drop, and reserve bandwidth. Based on the classification results, the CATNAP treatment module automatically applies the treatment policy to provide better QoS support. CATNAP is implemented with the NS network simulator, and evaluated against DropTail and Strict Priority Queue (SPQ) under various network and traffic conditions. In most simulation cases, CATNAP provides better QoS supports than DropTail: it lowers queuing delay for multimedia applications such as VoIP, games and video, fairly treats FTP flows with various round trip times, and is even functional when misbehaving UDP traffic is present. Unlike current QoS methods, CATNAP is a plug-and-play solution, automatically classifying and treating flows without any user configuration, or any modification to end hosts or applications

Interoperability of wireless communication technologies in hybrid networks: Evaluation of end-to-end interoperability issues and quality of service requirements

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.Hybrid Networks employing wireless communication technologies have nowadays brought closer the vision of communication “anywhere, any time with anyone”. Such communication technologies consist of various standards, protocols, architectures, characteristics, models, devices, modulation and coding techniques. All these different technologies naturally may share some common characteristics, but there are also many important differences. New advances in these technologies are emerging very rapidly, with the advent of new models, characteristics, protocols and architectures. This rapid evolution imposes many challenges and issues to be addressed, and of particular importance are the interoperability issues of the following wireless technologies: Wireless Fidelity (Wi-Fi) IEEE802.11, Worldwide Interoperability for Microwave Access (WiMAX) IEEE 802.16, Single Channel per Carrier (SCPC), Digital Video Broadcasting of Satellite (DVB-S/DVB-S2), and Digital Video Broadcasting Return Channel through Satellite (DVB-RCS). Due to the differences amongst wireless technologies, these technologies do not generally interoperate easily with each other because of various interoperability and Quality of Service (QoS) issues. The aim of this study is to assess and investigate end-to-end interoperability issues and QoS requirements, such as bandwidth, delays, jitter, latency, packet loss, throughput, TCP performance, UDP performance, unicast and multicast services and availability, on hybrid wireless communication networks (employing both satellite broadband and terrestrial wireless technologies). The thesis provides an introduction to wireless communication technologies followed by a review of previous research studies on Hybrid Networks (both satellite and terrestrial wireless technologies, particularly Wi-Fi, WiMAX, DVB-RCS, and SCPC). Previous studies have discussed Wi-Fi, WiMAX, DVB-RCS, SCPC and 3G technologies and their standards as well as their properties and characteristics, such as operating frequency, bandwidth, data rate, basic configuration, coverage, power, interference, social issues, security problems, physical and MAC layer design and development issues. Although some previous studies provide valuable contributions to this area of research, they are limited to link layer characteristics, TCP performance, delay, bandwidth, capacity, data rate, and throughput. None of the studies cover all aspects of end-to-end interoperability issues and QoS requirements; such as bandwidth, delay, jitter, latency, packet loss, link performance, TCP and UDP performance, unicast and multicast performance, at end-to-end level, on Hybrid wireless networks. Interoperability issues are discussed in detail and a comparison of the different technologies and protocols was done using appropriate testing tools, assessing various performance measures including: bandwidth, delay, jitter, latency, packet loss, throughput and availability testing. The standards, protocol suite/ models and architectures for Wi-Fi, WiMAX, DVB-RCS, SCPC, alongside with different platforms and applications, are discussed and compared. Using a robust approach, which includes a new testing methodology and a generic test plan, the testing was conducted using various realistic test scenarios on real networks, comprising variable numbers and types of nodes. The data, traces, packets, and files were captured from various live scenarios and sites. The test results were analysed in order to measure and compare the characteristics of wireless technologies, devices, protocols and applications. The motivation of this research is to study all the end-to-end interoperability issues and Quality of Service requirements for rapidly growing Hybrid Networks in a comprehensive and systematic way. The significance of this research is that it is based on a comprehensive and systematic investigation of issues and facts, instead of hypothetical ideas/scenarios or simulations, which informed the design of a test methodology for empirical data gathering by real network testing, suitable for the measurement of hybrid network single-link or end-to-end issues using proven test tools. This systematic investigation of the issues encompasses an extensive series of tests measuring delay, jitter, packet loss, bandwidth, throughput, availability, performance of audio and video session, multicast and unicast performance, and stress testing. This testing covers most common test scenarios in hybrid networks and gives recommendations in achieving good end-to-end interoperability and QoS in hybrid networks. Contributions of study include the identification of gaps in the research, a description of interoperability issues, a comparison of most common test tools, the development of a generic test plan, a new testing process and methodology, analysis and network design recommendations for end-to-end interoperability issues and QoS requirements. This covers the complete cycle of this research. It is found that UDP is more suitable for hybrid wireless network as compared to TCP, particularly for the demanding applications considered, since TCP presents significant problems for multimedia and live traffic which requires strict QoS requirements on delay, jitter, packet loss and bandwidth. The main bottleneck for satellite communication is the delay of approximately 600 to 680 ms due to the long distance factor (and the finite speed of light) when communicating over geostationary satellites. The delay and packet loss can be controlled using various methods, such as traffic classification, traffic prioritization, congestion control, buffer management, using delay compensator, protocol compensator, developing automatic request technique, flow scheduling, and bandwidth allocation

Subjective Audio Quality over a Secure IEEE 802.11n Draft 2.0 Wireless Local Area Network

This thesis investigates the quality of audio generated by a G.711 codec and transmission over an IEEE 802.11n draft 2.0 wireless local area network (WLAN). Decline in audio quality due to additional calls or by securing the WLAN with transport mode Internet Protocol Security (IPsec) is quantified. Audio quality over an IEEE 802.11n draft 2.0 WLAN is also compared to that of IEEE 802.11b and IEEE 802.11g WLANs under the same conditions. Audio quality is evaluated by following International Telecommunication Union Telecommunication Standardization Sector (ITU-T) Recommendation P.800, where human subjects rate audio clips recorded during various WLAN configurations. The Mean Opinion Score (MOS) is calculated as the average audio quality score given for each WLAN configuration. An 85% confidence interval is calculated for each MOS. Results suggest that audio quality over an IEEE 802.11n draft 2.0 WLAN is not higher than over an IEEE 802.11b WLAN when up to 10 simultaneous G.711 calls occur. A linear regression of the subjective scores also suggest that an IEEE 802.11n draft 2.0 WLAN can sustain an MOS greater than 3.0 (fair quality) for up to 75 simultaneous G.711 calls secured with WPA2, or up to 40 calls secured with both WPA2 and transport mode IPsec. The data strongly suggest that toll quality audio (MOS ≥ 4.0) is not currently practical over IEEE 802.11 WLANs secured with WPA2, even with the G.711 codec

Performance evaluation of HIP-based network security solutions

Abstract. Host Identity Protocol (HIP) is a networking technology that systematically separates the identifier and locator roles of IP addresses and introduces a Host Identity (HI) name space based on a public key security infrastructure. This modification offers a series of benefits such as mobility, multi-homing, end-to-end security, signaling, control/data plane separation, firewall security, e.t.c. Although HIP has not yet been sufficiently applied in mainstream communication networks, industry experts foresee its potential as an integral part of next generation networks. HIP can be used in various HIP-aware applications as well as in traditional IP-address-based applications and networking technologies, taking middle boxes into account. One of such applications is in Virtual Private LAN Service (VPLS), VPLS is a widely used method of providing Ethernet-based Virtual Private Network that supports the connection of geographically separated sites into a single bridged domain over an IP/MPLS network. The popularity of VPLS among commercial and defense organizations underscores the need for robust security features to protect both data and control information. After investigating the different approaches to HIP, a real world testbed is implemented. Two experiment scenarios were evaluated, one is performed on two open source Linux-based HIP implementations (HIPL and OpenHIP) and the other on two sets of enterprise equipment from two different companies (Tempered Networks and Byres Security). To account for a heterogeneous mix of network types, the Open source HIP implementations were evaluated on different network environments, namely Local Area Network (LAN), Wireless LAN (WLAN), and Wide Area Network (WAN). Each scenario is tested and evaluated for performance in terms of throughput, latency, and jitter. The measurement results confirmed the assumption that no single solution is optimal in all considered aspects and scenarios. For instance, in the open source implementations, the performance penalty of security on TCP throughput for WLAN scenario is less in HIPL than in OpenHIP, while for WAN scenario the reverse is the case. A similar outcome is observed for the UDP throughput. However, on latency, HIPL showed lower latency for all three network test scenarios. For the legacy equipment experiment, the penalty of security on TCP throughput is about 19% compared with the non-secure scenario while latency is increased by about 87%. This work therefore provides viable information for researchers and decision makers on the optimal solution to securing their VPNs based on the application scenarios and the potential performance penalties that come with each approach.HIP-pohjaisten tietoliikenneverkkojen turvallisuusratkaisujen suorituskyvyn arviointi. Tiivistelmä. Koneen identiteettiprotokolla (HIP, Host Identity Protocol) on tietoliikenneverkkoteknologia, joka käyttää erillistä kerrosta kuljetusprotokollan ja Internet-protokollan (IP) välissä TCP/IP-protokollapinossa. HIP erottaa systemaattisesti IP-osoitteen verkko- ja laite-osat, sekä käyttää koneen identiteetti (HI) -osaa perustuen julkisen avainnuksen turvallisuusrakenteeseen. Tämän hyötyjä ovat esimerkiksi mobiliteetti, moniliittyminen, päästä päähän (end-to-end) turvallisuus, kontrolli-informaation ja datan erottelu, kohtaaminen, osoitteenmuutos sekä palomuurin turvallisuus. Teollisuudessa HIP-protokolla nähdään osana seuraavan sukupolven tietoliikenneverkkoja, vaikka se ei vielä olekaan yleistynyt laajaan kaupalliseen käyttöön. HIP–protokollaa voidaan käyttää paitsi erilaisissa HIP-tietoisissa, myös perinteisissä IP-osoitteeseen perustuvissa sovelluksissa ja verkkoteknologioissa. Eräs tällainen sovellus on virtuaalinen LAN-erillisverkko (VPLS), joka on laajasti käytössä oleva menetelmä Ethernet-pohjaisen, erillisten yksikköjen ja yhden sillan välistä yhteyttä tukevan, virtuaalisen erillisverkon luomiseen IP/MPLS-verkon yli. VPLS:n yleisyys sekä kaupallisissa- että puolustusorganisaatioissa korostaa vastustuskykyisten turvallisuusominaisuuksien tarpeellisuutta tiedon ja kontrolliinformaation suojauksessa. Tässä työssä tutkitaan aluksi HIP-protokollan erilaisia lähestymistapoja. Teoreettisen tarkastelun jälkeen käytännön testejä suoritetaan itse rakennetulla testipenkillä. Tarkasteltavat skenaariot ovat verrata Linux-pohjaisia avoimen lähdekoodin HIP-implementaatioita (HIPL ja OpenHIP) sekä verrata kahden eri valmistajan laitteita (Tempered Networks ja Byres Security). HIP-implementaatiot arvioidaan eri verkkoympäristöissä, jota ovat LAN, WLAN sekä WAN. Kaikki testatut tapaukset arvioidaan tiedonsiirtonopeuden, sen vaihtelun (jitter) sekä latenssin perusteella. Mittaustulokset osoittavat, että sama ratkaisu ei ole optimaalinen kaikissa tarkastelluissa tapauksissa. Esimerkiksi WLAN-verkkoa käytettäessä turvallisuuden aiheuttama häviö tiedonsiirtonopeudessa on HIPL:n tapauksessa OpenHIP:iä pirnempi, kun taas WAN-verkon tapauksessa tilanne on toisinpäin. Samanlaista käyttäytymistä havaitaan myös UDP-tiedonsiirtonopeudessa. HIPL antaa kuitenkin pienimmän latenssin kaikissa testiskenaarioissa. Eri valmistajien laitteita vertailtaessa huomataan, että TCP-tiedonsiirtonopeus huononee 19 ja latenssi 87 prosenttia verrattuna tapaukseen, jossa turvallisuusratkaisua ei käytetä. Näin ollen tämän työn tuottama tärkeä tieto voi auttaa alan toimijoita optimaalisen verkkoturvallisuusratkaisun löytämisessä VPN-pohjaisiin sovelluksiin

On Cloud-based multisource Reliable Multicast Transport in Broadband Multimedia Satellite Networks

Multimedia synchronization, Software Over the Air, Personal Information Management on Cloud networks require new reliable protocols, which reduce the traffic load in the core and edge network. This work shows via simulations the performance of an efficient multicast file delivery, which advantage of the distributed file storage in Cloud computing. The performance evaluation focuses on the case of a personal satellite equipment with error prone channels

Interoperability of wireless communication technologies in hybrid networks : evaluation of end-to-end interoperability issues and quality of service requirements

Hybrid Networks employing wireless communication technologies have nowadays brought closer the vision of communication “anywhere, any time with anyone”. Such communication technologies consist of various standards, protocols, architectures, characteristics, models, devices, modulation and coding techniques. All these different technologies naturally may share some common characteristics, but there are also many important differences. New advances in these technologies are emerging very rapidly, with the advent of new models, characteristics, protocols and architectures. This rapid evolution imposes many challenges and issues to be addressed, and of particular importance are the interoperability issues of the following wireless technologies: Wireless Fidelity (Wi-Fi) IEEE802.11, Worldwide Interoperability for Microwave Access (WiMAX) IEEE 802.16, Single Channel per Carrier (SCPC), Digital Video Broadcasting of Satellite (DVB-S/DVB-S2), and Digital Video Broadcasting Return Channel through Satellite (DVB-RCS). Due to the differences amongst wireless technologies, these technologies do not generally interoperate easily with each other because of various interoperability and Quality of Service (QoS) issues. The aim of this study is to assess and investigate end-to-end interoperability issues and QoS requirements, such as bandwidth, delays, jitter, latency, packet loss, throughput, TCP performance, UDP performance, unicast and multicast services and availability, on hybrid wireless communication networks (employing both satellite broadband and terrestrial wireless technologies). The thesis provides an introduction to wireless communication technologies followed by a review of previous research studies on Hybrid Networks (both satellite and terrestrial wireless technologies, particularly Wi-Fi, WiMAX, DVB-RCS, and SCPC). Previous studies have discussed Wi-Fi, WiMAX, DVB-RCS, SCPC and 3G technologies and their standards as well as their properties and characteristics, such as operating frequency, bandwidth, data rate, basic configuration, coverage, power, interference, social issues, security problems, physical and MAC layer design and development issues. Although some previous studies provide valuable contributions to this area of research, they are limited to link layer characteristics, TCP performance, delay, bandwidth, capacity, data rate, and throughput. None of the studies cover all aspects of end-to-end interoperability issues and QoS requirements; such as bandwidth, delay, jitter, latency, packet loss, link performance, TCP and UDP performance, unicast and multicast performance, at end-to-end level, on Hybrid wireless networks. Interoperability issues are discussed in detail and a comparison of the different technologies and protocols was done using appropriate testing tools, assessing various performance measures including: bandwidth, delay, jitter, latency, packet loss, throughput and availability testing. The standards, protocol suite/ models and architectures for Wi-Fi, WiMAX, DVB-RCS, SCPC, alongside with different platforms and applications, are discussed and compared. Using a robust approach, which includes a new testing methodology and a generic test plan, the testing was conducted using various realistic test scenarios on real networks, comprising variable numbers and types of nodes. The data, traces, packets, and files were captured from various live scenarios and sites. The test results were analysed in order to measure and compare the characteristics of wireless technologies, devices, protocols and applications. The motivation of this research is to study all the end-to-end interoperability issues and Quality of Service requirements for rapidly growing Hybrid Networks in a comprehensive and systematic way. The significance of this research is that it is based on a comprehensive and systematic investigation of issues and facts, instead of hypothetical ideas/scenarios or simulations, which informed the design of a test methodology for empirical data gathering by real network testing, suitable for the measurement of hybrid network single-link or end-to-end issues using proven test tools. This systematic investigation of the issues encompasses an extensive series of tests measuring delay, jitter, packet loss, bandwidth, throughput, availability, performance of audio and video session, multicast and unicast performance, and stress testing. This testing covers most common test scenarios in hybrid networks and gives recommendations in achieving good end-to-end interoperability and QoS in hybrid networks. Contributions of study include the identification of gaps in the research, a description of interoperability issues, a comparison of most common test tools, the development of a generic test plan, a new testing process and methodology, analysis and network design recommendations for end-to-end interoperability issues and QoS requirements. This covers the complete cycle of this research. It is found that UDP is more suitable for hybrid wireless network as compared to TCP, particularly for the demanding applications considered, since TCP presents significant problems for multimedia and live traffic which requires strict QoS requirements on delay, jitter, packet loss and bandwidth. The main bottleneck for satellite communication is the delay of approximately 600 to 680 ms due to the long distance factor (and the finite speed of light) when communicating over geostationary satellites. The delay and packet loss can be controlled using various methods, such as traffic classification, traffic prioritization, congestion control, buffer management, using delay compensator, protocol compensator, developing automatic request technique, flow scheduling, and bandwidth allocation.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

A Credit-based Home Access Point (CHAP) to Improve Application Quality on IEEE 802.11 Networks

Increasing availability of high-speed Internet and wireless access points has allowed home users to connect not only their computers but various other devices to the Internet. Every device running different applications requires unique Quality of Service (QoS). It has been shown that delay- sensitive applications, such as VoIP, remote login and online game sessions, suffer increased latency in the presence of throughput-sensitive applications such as FTP and P2P. Currently, there is no mechanism at the wireless AP to mitigate these effects except explicitly classifying the traffic based on port numbers or host IP addresses. We propose CHAP, a credit-based queue management technique, to eliminate the explicit configuration process and dynamically adjust the priority of all the flows from different devices to match their QoS requirements and wireless conditions to improve application quality in home networks. An analytical model is used to analyze the interaction between flows and credits and resulting queueing delays for packets. CHAP is evaluated using Network Simulator (NS2) under a wide range of conditions against First-In-First- Out (FIFO) and Strict Priority Queue (SPQ) scheduling algorithms. CHAP improves the quality of an online game, a VoIP session, a video streaming session, and a Web browsing activity by 20%, 3%, 93%, and 51%, respectively, compared to FIFO in the presence of an FTP download. CHAP provides these improvements similar to SPQ without an explicit classification of flows and a pre- configured scheduling policy. A Linux implementation of CHAP is used to evaluate its performance in a real residential network against FIFO. CHAP reduces the web response time by up to 85% compared to FIFO in the presence of a bulk file download. Our contributions include an analytic model for the credit-based queue management, simulation, and implementation of CHAP, which provides QoS with minimal configuration at the AP

Models of internet connectivity for secondary schools in the Grahamstown circuit

Information and Communication Technologies (ICTs) are becoming more pervasive in South African schools and are increasingly considered valuable tools in education, promoting the development of higher cognitive processes and allowing teachers and learners access to a plethora of information. This study investigates models of Internet connectivity for secondary schools in the Grahamstown Circuit. The various networking technologies currently available to South African schools, or likely to become available to South African schools in the future, are described along with the telecommunications legislation which governs their use in South Africa. Furthermore, current ICT in education projects taking place in South Africa are described together with current ICT in education policy in South Africa. This information forms the backdrop of a detailed schools survey that was conducted at all the 13 secondary schools in the Grahamstown Circuit and enriched with experimental work in the provision of metropolitan network links to selected schools, mostly via Wi-Fi. The result of the investigation is the proposal of a Grahamstown Circuit Metropolitan Education Network

Quality of service differentiation for multimedia delivery in wireless LANs

Delivering multimedia content to heterogeneous devices over a variable networking environment while maintaining high quality levels involves many technical challenges. The research reported in this thesis presents a solution for Quality of Service (QoS)-based service differentiation when delivering multimedia content over the wireless LANs. This thesis has three major contributions outlined below: 1. A Model-based Bandwidth Estimation algorithm (MBE), which estimates the available bandwidth based on novel TCP and UDP throughput models over IEEE 802.11 WLANs. MBE has been modelled, implemented, and tested through simulations and real life testing. In comparison with other bandwidth estimation techniques, MBE shows better performance in terms of error rate, overhead, and loss. 2. An intelligent Prioritized Adaptive Scheme (iPAS), which provides QoS service differentiation for multimedia delivery in wireless networks. iPAS assigns dynamic priorities to various streams and determines their bandwidth share by employing a probabilistic approach-which makes use of stereotypes. The total bandwidth to be allocated is estimated using MBE. The priority level of individual stream is variable and dependent on stream-related characteristics and delivery QoS parameters. iPAS can be deployed seamlessly over the original IEEE 802.11 protocols and can be included in the IEEE 802.21 framework in order to optimize the control signal communication. iPAS has been modelled, implemented, and evaluated via simulations. The results demonstrate that iPAS achieves better performance than the equal channel access mechanism over IEEE 802.11 DCF and a service differentiation scheme on top of IEEE 802.11e EDCA, in terms of fairness, throughput, delay, loss, and estimated PSNR. Additionally, both objective and subjective video quality assessment have been performed using a prototype system. 3. A QoS-based Downlink/Uplink Fairness Scheme, which uses the stereotypes-based structure to balance the QoS parameters (i.e. throughput, delay, and loss) between downlink and uplink VoIP traffic. The proposed scheme has been modelled and tested through simulations. The results show that, in comparison with other downlink/uplink fairness-oriented solutions, the proposed scheme performs better in terms of VoIP capacity and fairness level between downlink and uplink traffic

Investigating wireless network deployment configurations for marginalized areas

In recent years, immense effort has been channelled towards the Information and Technological development of rural areas. To support this development, telecommunication networks have been deployed. The availability of these telecommunication networks is expected to improve the way people share ideas and communicate locally and globally, reducing limiting factors like distance through the use of the Internet. The major problem for these networks is that very few of them have managed to stay in operation over long periods of time. One of the major causes of this failure is the lack of proper monitoring and management as, in some cases, administrators are located far away from the network site. Other factors that contribute to the frequent failure of these networks are lack of proper infrastructure, lack of a constant power supply and other environmental issues. A telecommunication network was deployed for the people of Dwesa by the Siyakhula Living Lab project. During this research project, frequent visits were made to the site and network users were informally interviewed in order to gain insight into the network challenges. Based on the challenges, different network monitoring systems and other solutions were deployed on the network. This thesis analyses the problems encountered and presents possible and affordable solutions that were implemented on the network. This was done to improve the network‟s reliability, availability and manageability whilst exploring possible and practical ways in which the connectivity of the deployed telecommunication network can be maintained. As part of these solutions, a GPRS redundant link, Nagios and Cacti monitoring systems as well as Simple backup systems were deployed. v Acronyms AC Access Concentrators AMANDA Automatic Marylyn Network Disk Archiver CDMA Code Divison Multiple Access CGI Common Gateway Interface