<p>The need for AAA protocols in the world are increasing and todays most common protocols RADIUS and TACACS+, cannot cope with the fast advances in fields benefiting from the use of AAA protocols. This is why IETF has developed the protocol Diameter as a next generations AAA protocol. The objective of this thesis is to account for the work conducted with Diameter as well as to determine if it is going to become the major AAA protocol of the next generation. In this thesis, I describe what Diameter is, its close integration with the Mobile IP protocol and its other uses. As Diameter is based on RADIUS an introduction to AAA and RADIUS is given in order to comprehend where we are today and where we are going as well as to why. I also compare today’s protocols (RADIUS, TACACS+, Kerberos and COPS) against the next generations AAA protocol Diameter. From this comparison, the Mobile IP integration capabilities and an analysis of the support of the Diameter protocol I have come to the conclusion that Diameter is going to become the major AAA protocol of the next generation.</p>

The need for AAA protocols in the world are increasing and todays most common protocols RADIUS and TACACS+, cannot cope with the fast advances in fields benefiting from the use of AAA protocols. This is why IETF has developed the protocol Diameter as a next generations AAA protocol. The objective of this thesis is to account for the work conducted with Diameter as well as to determine if it is going to become the major AAA protocol of the next generation. In this thesis, I describe what Diameter is, its close integration with the Mobile IP protocol and its other uses. As Diameter is based on RADIUS an introduction to AAA and RADIUS is given in order to comprehend where we are today and where we are going as well as to why. I also compare today’s protocols (RADIUS, TACACS+, Kerberos and COPS) against the next generations AAA protocol Diameter. From this comparison, the Mobile IP integration capabilities and an analysis of the support of the Diameter protocol I have come to the conclusion that Diameter is going to become the major AAA protocol of the next generation.

Ingeniera Civil Electricista / La evolución de las redes de comunicaciones móviles avanza hacia la unificación de un ambiente heterogéneo en el cual se interconectan entre sí redes de distintos accesos. En este escenario, la mantención de sesiones de internet de los usuarios, cuando éstos se mueven de una red a otra, emerge como uno de los principales desafíos a enfrentar. La introducción de un protocolo de movilidad en la red aparece como solución a este problema, facilitando el roaming entre redes y evitando la reconexión de las sesiones del usuario. El despliegue de redes wireless de área local (WLAN) es un económico medio para acceder a internet a diferencia de las redes celulares con soporte de redes de paquetes. Mientras que las redes WLAN poseen un ancho de banda significativamente mayor al de las redes móviles, estas redes poseen una amplia cobertura que incentiva la interconexión entre ambas tecnologías. En este trabajo se desarrolla un modelo de interconexión de redes celulares y WLANs utilizando Mobile IP. Las simulaciones se realizan en el software computacional OPNET y el soporte de movilidad se enfoca desde el nivel IP utilizando los protocolos Mobile IP en un ambiente global; y Proxy Mobile IP en un ambiente localizado, ambos en su versión IPv4. Los resultados MIP muestran una asimetría entre delays end-to-end producto del camino triangular del tráfico de datos. Esto lleva a una ineficiencia en el ruteo que afecta principalmente a aplicaciones en tiempo real. El roaming hacia la red WLAN provoca una disminución en los delays end-to-end en ambas direcciones situándose entre 56 % y 71 % cuando el estado de la red de internet tiene asociado una baja latencia. El establecimiento de sesiones TCP sube en un 7 % mientras que el control de aplicaciones de descarga FTP baja en 29 %. En el caso de PMIP, el 3-way handshake disminuye en un 14 % mientras que el control de aplicación FTP en un 41 %. Este protocolo no evidencia ineficiencia en el ruteo, tendiéndose además una disminución de delays end-to-end incluso con latencia de red de 100 ms. Lo positivo de enfocar la movilidad desde el nivel IP se encuentra en la indiferencia que supone el tipo de acceso a nivel de capa de enlace. La ventaja de PMIP sobre MIP es que no requiere de software especializado en el cliente, reduciendo así los costos de señalización en el establecimiento del servicio de movilidad. MIP por su parte, es idóneo de ser utilizado en un esquema de interconexión global, por lo que su integración con PMIP puede ser vista de manera complementaria estableciendo un esquema jerárquico con este último proveyendo movilidad a nivel local.

With recent growth in mobile components and advances in wireless communication technology, mobile computing is an increasingly important area of research. Enabling mobility in IP networks becomes more and more significant. Mobile IP is the only current means for offering seamless roaming to mobile computers in the Internet. It has recently progressed along the ladder to standardization within the Internet Engineering Task Force (IETF). However, Mobile IP suffers from so-called triangular-routing problem and packet loss due to handoff. In this paper, we propose a new architecture to solve these two problems noted above. We assume that network routers such as Home Agent¡BForeign Agent¡BGeneral Router can equip our Pre-Accessing Engine (Mobile IP Engine) to access IP packets before IP routing Engine. With our Mobile IP table established in Mobile IP Engine, we can set up a transmission path for each correspondent node (CN) to transmit data to mobile node (MN). Therefore, we not only solve triangular-routing problem by direct transmission path, but also decrease handoff latency from path updating function. Furthermore, we use retransmission and flush schemes to avoid packet loss and out-of-order problems. Finally, we use simulation to prove our architecture is useful.

In wireless/mobile networks, users freely change their service point while they are communicating with other users. In order to support the mobility of mobile nodes, Mobile IPv6 (MIPv6) is proposed in IETF, in which an MN must inform its home agent the binding of its home address and the current care-of address (CoA). The home agent forwards packets to CoA when it receives packets for the MN. There is a significant problem in MIPv6 due to its inability to support micro-mobility cause by long delay and high packet loss during handover. Hierarchical mobile IPv6 (HMIPv6) is proposed to separate mobility into micro-mobility (within one domain) and macro-mobility (between domains). HMIPv6 introduced a new protocol element called Mobility Anchor Point (MAP) to manage the mobility. HMIPv6 can reduce the delay and the amount of signaling during handover. However HMIPv6 only improves micro mobility problem where the significant delay still occurs in macro mobility management. Duplicate address detection and the transmission time during the handoff operation could cause high delays. This paper considers handover operations. By simulations, we show that the proposed scheme can realize low handoff delay and packet loss during handover.

There are two critical issues involved as a mobile node moving across two different network sub-domains. One of them is to minimize the possible packet loss and the other is to shorten the handover time. Fast handover is a remedy to these problems. It minimizes the packet loss by making use of buffers, and speed up the handover procedure by L2 triggering. There are two components contributing to the handover delay, namely L2 handover delay and L3 handover delay. The L3 handover delay consists of movement detection delay, duplicate address detection delay, as well as registration delay. With fast handover, the movement detection delay can be lowered by using L2 trigger, and the registration delay can be decreased by buffering and tunneling. However, the problem of out-of-order packets is still in its existence. A novel handover scheme incorporating the anycast technology is developed and presented in this thesis. With refined buffer control scheme and the switching between unicast and anycast addressing, the handover performance can be greatly improved by the proposed approach.

Many different wireless technologies have increased the demand of accessing Internet resources through wireless networks. One of the most popular applications is watching multimedia streaming over wireless. However, when a user is roaming in a heterogeneous network, he needs to acquire adequate bandwidth from different wireless access points. In this Thesis, we propose a Mobile-IP based vertical handoff scheme in a heterogeneous WiMAX and WLAN. When a mobile node is in the overlapped area of WiMAX and WLAN, it may have to execute the vertical handoff based on the received average signal strength, the transmitting queue length of network interface, and the available network bandwidth. Our goal is to reduce the influences of RTP-based video streaming when the network is congested and when a mobile node executes the vertical handoff in the heterogeneous network. We implement the Dynamic Mobile-IP based vertical handoff on Linux platform by modifying handoff decisions between WiMAX and WLAN. The above-mentioned performance parameters are implemented as modules on Linux platform. At last, we prove that our scheme can effectively improve packet loss ratio and system processing ratio. As a result, the frame mosaic phenomenon and frame slow-playing phenomenon in RTP-based video streaming can be significantly improved.

Traditional Mobile IP supports only one tunnel between HA (Home Agent) and FA (Foreign Agent) for MN (Mobile Node) to transmit data from CN (Corresponding Node) to MN during handoff. To alleviate traffic load, in this Thesis, we propose a multiple-tunnel approach by setting up a secondary tunnel in addition to the primary tunnel. HA can split the video stream from the primary tunnel to the secondary tunnel when the former encounters high traffic load. Thus, quality of video stream from CN to MN can be guaranteed through the proposed multiple-tunnel schemes. For the purpose of validation, we implement the multiple-tunnel schemes on Linux platform for HA, FA, and MN to support video stream splitting. Specifically, if HA detects that high system load occurs on FA, an MPEG-4 packet filter is activated on HA to split some portions of video packets from the primary tunnel to the secondary tunnel based on I/B/P frame types. Video receiver on MN can then successfully recover these two divided video packets and playback the complete stream smoothly. Three experiments for validation are developed. They are (i) a simple Mobile IP handoff, (ii) Different bit rates to activate the stream splitting mechanism, and (iii) automatic adjustment of stream splitting according to system load. The experimental results have proved that the proposed multiple-tunnel schemes can substantially improve the quality of video streams.

The Mobile INTernet router (MINT for short) is a core element of the Walkstation II Project. Its purpose is to link via a radio resource one or many mobile hosts, the latter are either independant or connected together forming a isolated subnetwork. The MINT has a communication device consisting of an Ethernet Controller and a radio tranceiver, currently working at 2GHz. The RadioNet Driver, a device driver is used control these pieces of hardware. Progress has been slow. Initial work involved exploring the MINT's programming environment (cross-compiler, debugger) and doing some experiments with the MINTs. Next, a dummy RadioNet driver was written to become familiar with programming in the (SunOS) kernel. Then the LANCE driver for the MACH kernel was modified, resulting in the RadioNet driver. This talk will decribe the tools and the current status of the RadioNet driver. / <p>Just as for Markus Oelhafen's thesis, Pascal was an exchange student with EURECOM, so I do not know the credits or even if he was registered at KTH.</p>

High data rate wireless packet data networks have made real-time IP based services available through mobile devices. At the same time, differences in the characteristics of radio technologies (802.11/WiFi and 3G networks) make seamless handoff across heterogeneous wireless networks difficult. Despite this, many believe that the ultimate goal of next generation networks (often referred to as the fourth generation) is to allow convergence of such dissimilar heterogeneous networks. Supporting voice over Internet Protocol in next-generation wireless systems is thought by some to require support for mobility and quality of service features. Currently a mobile node can experience interruptions or even sporadic disconnections of an on going real-time session due to handovers between both networks of different types and networks of the same type. Many tests have already been done in this area and one may wonder why it is worth spending even more time investigating it? This thesis focuses on the important problem of providing session security despite handovers between networks (be they operated by the same operator or different operators and be they the same link technologies or different). One of the goals in this thesis is to investigate how an ongoing speech session can continue despite a change in transmission media1. Additionally, a number of security threats that could occur due to the handover will be identified and presented. Finally, the most suitable solution to address these threats will be tested in a real environment. Eventual shortcomings and weaknesses will be identified and presented; along with suggestions for future work.  1 When utilizing IP over carriers such as wired Ethernet, WLAN, and 3G. / Trådlösa hög-hastighets datanät har möjliggjort appliceringen av realtids tjänster på mobil utrustning över IP. Samtidigt har skillnaderna i de olika radioteknologierna (802.11/WiFi och 3G näten) introducerat nya problem med att upprätthålla trådlösa kommunikationen tvärs den heterogena trådlösa accessen. Många tror att slutmålet för nästa generations nätverk (ofta refererade som fjärde generationens nätverk) är att tillåta konvergensen av dessa olika heterogena nätverk. Stödet för Voice over Internet Protokollet (VoIP) i nästa generations trådlösa nät tror somliga kräver ett inslag av kombination mellan mobilitet samt upprätthållandet av kvaliteten. För närvarande kan den mobila noden (MN) råka ut för störningar och även sporadiska avbrott av en pågående realtidssessionen på grund av övergångar mellan samma eller olika typer av medier. Många tester har redan gjorts inom det här området och man kan fråga sig varför det är värt att lägga ner ännu mer tid på att undersöka det här? Det här examensarbetet fokuserar på det viktiga problemet som handlar om att kunna erbjuda sessions säkerhet trots övergångar mellan näten (oavsett om dessa drivs av samma eller olika operatörer samt oavsett om de är av samma eller olika nätverks typ). Ett av målen för det här examensarbetet är att undersöka hur en pågående talsession behålls vid byte av transmissionsmedia2. Vidare kommer olika säkerhetsaspekter och hot som kan tänkas uppstå vid bytet att identifieras och presenteras. Slutligen kommer den mest lämpade lösningen till problemet att testas i verklig miljö. Eventuella brister och svagheter kommer att identifieras och redovisas i slutet av rapporten tillsammans med förslag på framtida arbete. 2 Då man nyttjar IP bärare som trådbundet Ethernet, WLAN och 3G.