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<p>Border Gateway Protocol (BGP) is a critical routing protocol of the internet, used to</p><p>exchange routing information between autonomous systems (ASes). BGP is highly</p><p>vulnerable to many attacks that can cause routing disturbance on the internet. This</p><p>paper describes BGP attacks, misconfigurations, causes of misconfigurations, impact</p><p>of these attacks and misconfigurations in BGP and counter measures. Also we</p><p>analyze new security architectures for BGP, comparison of these security protocols</p><p>and their deployment issues. At the end we propose new security solution that is</p><p>Defensive Routing Policy (DRP) to prevent BGP from malicious attacks and</p><p>misconfigurations. DRP is operationally deployable and very effective to solve BGP</p><p>problems.</p>

Abstract With the prosperity of the internet network, there are more and more wireless mobile devices producing, so people are greater and greater to the demand for internet access at any time. Some studies that integrate the Ad Hoc network into the internet in order to achieve the aim of the internet access on the go. Among them someone proposes that there is a part of Ad Hoc network MNs that can connect with BS, these MNs can be selected to act as Internet Gateway(IG), other MNs which can not connect with BS will convey the date to the internet through the IG. But IG itself is a MN, so IG switching is the most important factor to influence the performance of network, because at this switching time, Ad Hoc network does not connect with internet, all MNs must suspend transmission. If this swtiching time is too long, that will cause the efficiency of the network to glide seriously. Therefore, we propose some improvement methods and combine L2 trigger to reduce the delay time, and we utilize AR and BG selection to determine new DG produced to reduce DG switching times. Keyword: ad hoc¡AGateway

Border Gateway Protocol (BGP) is a critical routing protocol of the internet, used to exchange routing information between autonomous systems (ASes). BGP is highly vulnerable to many attacks that can cause routing disturbance on the internet. This paper describes BGP attacks, misconfigurations, causes of misconfigurations, impact of these attacks and misconfigurations in BGP and counter measures. Also we analyze new security architectures for BGP, comparison of these security protocols and their deployment issues. At the end we propose new security solution that is Defensive Routing Policy (DRP) to prevent BGP from malicious attacks and misconfigurations. DRP is operationally deployable and very effective to solve BGP problems.

As network bandwidth growing and voice coding enhancing, voice transmitted over the Packet-Based network environment can also have good quality compared to traditional telephone network. Therefore, the IP telephony services having a price advantage could gradually replace the traditional telecommunication services. However, in order to support both the traditional telecommunication services and IP phone services, it requires the devices which are capable of converting analogical telephony information such as voice and fax into packet data suitable for transmitting over IP. We therefore design and implement an IP phone equipment that can make SIP phone calls, and can support the exchange of the analogical traditional telephone voice and the digital voice packets over IP. In the hardware design point of view, we implement an IP phone set device in an embedded development platform using Infineon EASY5120 development kit, which uses a digital signal processor, called Vinetic&#x00AE;-2CPE (part number is PEB3332), to handle voice encoding and decoding, e.g., G.711 u/A law and G.723 compression, and RTP encapsulation and decapsulation. In the software architecture, we choose Linux as our embedded operation system under which there are lots of GNU open source software to feed our need and further to develop our own software components. In the process of this implementation, the software and hardware co-design takes up most of time, and we also face some VoIP application problems, e.g., SIP. We try to build up a VoIP system to figure out and solve these problems. And we hope that this actually applicable VoIP embedded system can be used as a testbed and verifying platform for VoIP applications.

With the bandwidth growing and voice coding technology enhancing, VoIP(Voice over IP)becomes a very popular application in recent years. Although VoIP has good voice quality and huge price advantage, it can't replace PSTN(Public Switched Telephone Network) completely in the next few years. We therefore hope to be able to solve the connectivity issue between PSTN and VoIP. In this thesis, I design and implement a VoIP Gateway using Infineon EASY 5120 platform which has a powerful CPU with network processor, ADM5120, and has a DSP (Digital Signal Processor), Vinetic-2CPE PEB3332, to handle digital and analog voice signals. The operation method of the gateway is that PSTN analog signals are passed to Vinetic-2CPE from FXO (Foreign eXchange Office) port, and they are transferred into digital signals to be packetized to transit into Internet to another VoIP Client. My VoIP Gateway can solve the interconnection issues between PSTN and VoIP. Furthermore, in order to solve NAT traversal problem of SIP protocol, we propose and implement an integration approach which uses STUN (Simple Traversal of UDP through NAT) to cooperate with RTP Relay server to traverse various types of NAT, especial symmetric NAT. My VoIP Gateway not only can traverse any type of NAT but also can perform self-configuration according to STUN test report in various network environments.

Because of Skype, Voice over IP(VoIP) becomes much more hot and popular. It has always been considered to be a killer application of new generation of the Internet. With its distinct economic advantage and good voice quality, it has the tendency to replace the traditional Public Service Telephone Network(PSTN). Moreover, Session Initiation Protocol(SIP) is proposed by Next Generation Network(NGN) to be the first choice of voice and multimedia network control protocol. Client-server is the key architecture of SIP. Although this architecture is simple and easy to maintain, and even it has faster response time than P2P, the server may cause problems while the client is increasing. Moreover, it is possible that the large load may cause the service stop anytime. In this paper, we discuss how to design and implement an embedded VoIP user agent based on SIP standard. It can improve efficiency of SIP signaling delivery through the user characteristic of making calls with limited resources and reduce the number of services that servers to provide while calling. We also design a graphical user interface. The interface lets users feel friendly and make the method of the system more efficient.

Zugl.: Rostock, Univ., Diss., 2008

This study focuses on the Internet of Things (IoT) gateway; a common middleware solution that bridges the gap between physical sensors and devices to internet applications. There is a shown interest in understanding the characteristics of different types of gateway architectures both from the research field and the industry, particularly the IT-consulting firm Attentec in Linköping, Sweden. A study has also been made on the open source C library libuv, used in the common web runtime engine NodeJS. The library has been used to study how asynchronous I/O operations can be used to improve the IoT gateway performance. A set of three general architectural approaches are identified. Common internal and external properties are identified based on state-of-the-art gateway implementations found in the industry. All of these properties are taken into account when a general gateway implementation is developed that is proposed to mimic any architectural level implementation of the gateway. A set of performance tests are conducted on the implementation to observe how different configurations of the gateway affect throughput and response time of data transmitted from simulated devices. The results show that the properties of the gateway do affect throughput and response time significantly and that libuv overall helps implement one of the best performing gateway configurations.

Nous considérons, dans cette thèse, un nouveau service par lequel les opérateurs de télécommunications offrent des routes supplémentaires à leurs clients (en plus de la route par défaut) comme un service gratuit ou à valeur ajoutée. Ces routes supplémentaires peuvent être utilisées par des clients afin d’optimiser leurs communications, en outrepassant des points de congestion d’Internet, ou les aider à atteindre leurs objectifs d’ingénierie de trafic (meilleurs délais etc.) ou dans un but de robustesse. Nous proposons d’abord une architecture simple permettant à un opérateur de télécommunication de bénéficier de la diversité de chemin qu’il reçoit déjà. Nous étendons ensuite cette architecture afin de rendre possible la propagation de cette diversité de chemin, non seulement aux voisins directs mais aussi, de proche en proche, aux autres domaines. Nous profitons de cette occasion pour relaxer la sélection des routes des différents domaines afin de leur permettre de mettre en place de nouveaux paradigmes de routage. Néanmoins, annoncer des chemins additionnels peut entrainer des problèmes de passage à l’échelle car chaque opérateur peut potentiellement recevoir plus de chemins que ce qu’il peut gérer. Nous quantifions ce problème et mettons en avant des modifications et filtrages simples permettant de réduire ce nombre à un niveau acceptable. En dernier, nous proposons un processus, inspiré des ventes aux enchères, permettant aux opérateurs de propager aux domaines voisins seulement les chemins qui intéressent les dits voisins. De plus, ce processus permet de mettre en avant un nouveau paradigme de propagation de routes, basé sur des négociations et accords commerciaux / In this thesis we consider a new service where carriers offer additional routes to their customers (w.r.t. to the BGP default route) as a free or value-added service. These alternate routes can be used by customers to optimize their communications, by bypassing some congested points in the Internet (e.g. a “tussled” peeringpoints), to help them to meet their traffic engineering objectives (better delays etc.) or just for robustness purposes (e.g, shift to a disjoint alternate route if needed). First we propose a simple architecture that allows a network service provider to benefit from the diversity it currently receives. Then we extend this architecture in order to make the propagation of the Internet path diversity possible, not only to direct neighbors but also to their neighbors and so on. We take advantage of this advance to relax the route selection processes of autonomous systems in order to make them be able to set up new routing paradigms. Nevertheless announcing additional paths can lead to scalability issues, so each carrier could receive more paths than what it could manage. We quantify this issue and we underline easy adaptations and small path filterings which make the number of paths drop to a manageable amount. Last but not least we set up an auction-type route allocation framework, which gives to network service providers the opportunities first to propagate to their neighbors only the paths the said neighbors are interested in and second to leverage a new routing selection paradigm based on commercial agreements and negotiations