Encaminhamento e segurança em redes veiculares

Mestrado em Engenharia Electrónica e TelecomunicaçõesThe growing research in vehicular network solutions provided the rise of interaction in these highly dynamic environments in the market. The developed architectures do not usually focus, however, in security aspects. Common security strategies designed for the Internet require IP. Since nodes' addresses in a vehicular network are too dynamic, such solutions would require cumbersome negotiations, which would make them unsuitable to these environments. The objective of this dissertation is to develop, and test a scalable, lightweight, layer 3 security protocol for vehicular networks, in which nodes of the network are able to set up long-term security associations with a Home Network, avoiding session renegotiations due to lack of connectivity and reduce the protocol stacking. This protocol allows to provide security independent of the nodes (vehicles) position, of its addressing and of the established path to access the Internet, allowing the mobility of vehicles and of its active sessions seamlessly without communication failures.O crescimento da investigação em redes veiculares provocou o aumento da interação nestes ambientes muito dinâmicos no mercado. As arquiteturas desenvolvidas não se focam, no entanto, na segurança. Estratégias comuns de segurança para a Internet, requerem sessões baseadas no IP. Como os endereços dos nós numa rede veicular, e a sua localização e caminhos até à Internet, são muito dinâmicos, as soluções já desenvolvidas para outro tipo de redes iriam requerer renegociações que teriam um grande impacto no desempenho destes ambientes. O objetivo desta dissertação será, portanto, desenvolver e testar um protocolo de segurança implementado na camada 3 para redes veiculares, que seja escalável e leve, em que os nós da rede conseguirão estabelecer associações de segurança de longa duração com a Home Network, evitando renegociações devidas à falta de conectividade, e reduzir o overhead devido ao empilhamento protocolar. Este protocolo permite ter segurança independentemente da posição dos nós (os veículos), do seu endereçamento e do caminho estabelecido para o acesso à Internet, permitindo assim mobilidade dos veículos e das sessões ativas de forma transparente sem falhas na comunicação

A Model for User Based IP Traffic Accounting

Nowadays, accounting, charging and billing users' network resource consumption are commonly used for the purpose of facilitating reasonable network usage, controlling congestion, allocating cost, gaining revenue, etc. In traditional IP traffic accounting systems, IP addresses are used to identify the corresponding consumers of the network resources. However, there are some situations in which IP addresses cannot be used to identify users uniquely, for example, in multi-user systems. In these cases, network resource consumption can only be ascribed to the owners of these hosts instead of corresponding real users who have consumed the network resources. Therefore, accurate accountability in these systems is practically impossible. This is a flaw of the traditional IP address based IP traffic accounting technique. This dissertation proposes a user based IP traffic accounting model which can facilitate collecting network resource usage information on the basis of users. With user based IP traffic accounting, IP traffic can be distinguished not only by IP addresses but also by users. In this dissertation, three different schemes, which can achieve the user based IP traffic accounting mechanism, are discussed in detail. The inband scheme utilizes the IP header to convey the user information of the corresponding IP packet. The Accounting Agent residing in the measured host intercepts IP packets passing through it. Then it identifies the users of these IP packets and inserts user information into the IP packets. With this mechanism, a meter located in a key position of the network can intercept the IP packets tagged with user information, extract not only statistic information, but also IP addresses and user information from the IP packets to generate accounting records with user information. The out-of-band scheme is a contrast scheme to the in-band scheme. It also uses an Accounting Agent to intercept IP packets and identify the users of IP traffic. However, the user information is transferred through a separated channel, which is different from the corresponding IP packets' transmission. The Multi-IP scheme provides a different solution for identifying users of IP traffic. It assigns each user in a measured host a unique IP address. Through that, an IP address can be used to identify a user uniquely without ambiguity. This way, traditional IP address based accounting techniques can be applied to achieve the goal of user based IP traffic accounting. In this dissertation, a user based IP traffic accounting prototype system developed according to the out-of-band scheme is also introduced. The application of user based IP traffic accounting model in the distributed computing environment is also discussed.Ein Modell für Nutzerbasiertes IP-Verkehr Accountin