Roaming Real-Time Applications - Mobility Services in IPv6 Networks

Emerging mobility standards within the next generation Internet Protocol, IPv6, promise to continuously operate devices roaming between IP networks. Associated with the paradigm of ubiquitous computing and communication, network technology is on the spot to deliver voice and videoconferencing as a standard internet solution. However, current roaming procedures are too slow, to remain seamless for real-time applications. Multicast mobility still waits for a convincing design. This paper investigates the temporal behaviour of mobile IPv6 with dedicated focus on topological impacts. Extending the hierarchical mobile IPv6 approach we suggest protocol improvements for a continuous handover, which may serve bidirectional multicast communication, as well. Along this line a multicast mobility concept is introduced as a service for clients and sources, as they are of dedicated importance in multipoint conferencing applications. The mechanisms introduced do not rely on assumptions of any specific multicast routing protocol in use.Comment: 15 pages, 5 figure

Implementing label filters on a shared tree mobile multicast architecture

This paper describes an architecture that filters packets within a subset of nodes on an existing shared multicast tree. The path connecting the group of nodes that want to communicate privately on the existing tree was given a label. These labels are used to route one-to-one and group communication traffic for selected nodes on a multicast tree. Nodes connected to the tree but are not on this label path do not receive any filtered packets. This filter architecture reduces network resource waste by utilising the existing network resources on the multicast tree like quality of service (QoS). In this paper, we also describe how this architecture can be used for mobile communication when implemented in a shared tree mobile multicast architecture

An adaptive membership management algorithm for application layer multicast

Due to deployment difficulty of network layer multicast, application layer multicast is considered to be a good substitute for massive P2P video/audio streaming in large networks. However, in application layer multicast, the participating users join and leave the on-going session at will. Therefore, a scalable and reliable group membership management algorithm is necessary due to the highly dynamic nature of the overlay network, built on top of the Internet. Gossip-based algorithms seem to be a solution. However, most gossip-based membership management algorithms lack flexibility, and are unable to adapt to the everchanging network dynamics, imposing roughly the same amount of overhead on the network. A new adaptive gossip-based membership management algorithm is proposed to bridge the gap. This algorithm captures the changes of the network and adjusts the parameter settings dynamically, bringing adaptivity and reducing overhead. Simulation results indicate a maximum of 50% reduction can be achieved in terms of network overhead on core network components, such as backbone links and attached routers, without sacrificing reliability and scalabilit

Secure Routing in Wireless Mesh Networks

Wireless mesh networks (WMNs) have emerged as a promising concept to meet the challenges in next-generation networks such as providing flexible, adaptive, and reconfigurable architecture while offering cost-effective solutions to the service providers. Unlike traditional Wi-Fi networks, with each access point (AP) connected to the wired network, in WMNs only a subset of the APs are required to be connected to the wired network. The APs that are connected to the wired network are called the Internet gateways (IGWs), while the APs that do not have wired connections are called the mesh routers (MRs). The MRs are connected to the IGWs using multi-hop communication. The IGWs provide access to conventional clients and interconnect ad hoc, sensor, cellular, and other networks to the Internet. However, most of the existing routing protocols for WMNs are extensions of protocols originally designed for mobile ad hoc networks (MANETs) and thus they perform sub-optimally. Moreover, most routing protocols for WMNs are designed without security issues in mind, where the nodes are all assumed to be honest. In practical deployment scenarios, this assumption does not hold. This chapter provides a comprehensive overview of security issues in WMNs and then particularly focuses on secure routing in these networks. First, it identifies security vulnerabilities in the medium access control (MAC) and the network layers. Various possibilities of compromising data confidentiality, data integrity, replay attacks and offline cryptanalysis are also discussed. Then various types of attacks in the MAC and the network layers are discussed. After enumerating the various types of attacks on the MAC and the network layer, the chapter briefly discusses on some of the preventive mechanisms for these attacks.Comment: 44 pages, 17 figures, 5 table

Security and Privacy Issues in Wireless Mesh Networks: A Survey

This book chapter identifies various security threats in wireless mesh network (WMN). Keeping in mind the critical requirement of security and user privacy in WMNs, this chapter provides a comprehensive overview of various possible attacks on different layers of the communication protocol stack for WMNs and their corresponding defense mechanisms. First, it identifies the security vulnerabilities in the physical, link, network, transport, application layers. Furthermore, various possible attacks on the key management protocols, user authentication and access control protocols, and user privacy preservation protocols are presented. After enumerating various possible attacks, the chapter provides a detailed discussion on various existing security mechanisms and protocols to defend against and wherever possible prevent the possible attacks. Comparative analyses are also presented on the security schemes with regards to the cryptographic schemes used, key management strategies deployed, use of any trusted third party, computation and communication overhead involved etc. The chapter then presents a brief discussion on various trust management approaches for WMNs since trust and reputation-based schemes are increasingly becoming popular for enforcing security in wireless networks. A number of open problems in security and privacy issues for WMNs are subsequently discussed before the chapter is finally concluded.Comment: 62 pages, 12 figures, 6 tables. This chapter is an extension of the author's previous submission in arXiv submission: arXiv:1102.1226. There are some text overlaps with the previous submissio

Effective Mobile Routing Through Dynamic Addressing

Military communications has always been an important factor in military victory and will surely play an important part in future combat. In modern warfare, military units are usually deployed without existing network infrastructure. The IP routing protocol, designed for hierarchical networks cannot easily be applied in military networks due to the dynamic topology expected in military environments. Mobile ad-hoc networks (MANETs) represent an appropriate network for small military networks. But, most ad-hoc routing protocols suffer from the problem of scalability for large networks. Hierarchical routing schemes based on the IP address structure are more scalable than ad-hoc routing but are not flexible for a network with very dynamic topology. This research seeks a compromise between the two; a hybrid routing structure which combines mobile ad-hoc network routing with hierarchical network routing using pre-planned knowledge about where the various military units will be located and probable connections available. This research evaluates the performance of the hybrid routing and compares that routing with a flat ad-hoc routing protocol, namely the Ad-hoc On-demand Distance Vector (AODV) routing protocol with respect to goodput ratio, packet end to- end delay, and routing packet overhead. It shows that hybrid routing generates lower routing control overhead, better goodput ratio, and lower end-to-end packet delay than AODV routing protocol in situations where some a-priori knowledge is available