Internetworking

Theme leader: Associate Professor Bjorn Landfeldt

There is a great need to reignite the Internet revolution to create new research and business opportunities and there are a number of international initiatives attempting to achieve this goal. Also, with the wide availability of low-cost computers and pervasive network connectivity, many organisations are facing the need to manage large collections of distributed resources. These might include personal workstations, dedicated nodes in a distributed application such as a web farm, or objects stored on these computers. The computers may be co-located in a room, spread across a building or campus, or even scattered around the world.

There is also the need to integrate ‘wired’ and ‘wireless’ infrastructures to enable better connectivity and access to wider range of services. Configurations of these systems change rapidly failures and changes in connectivity are the norm, and significant adaptation may be required if the application is to maintain desired levels of service.

To a growing degree, applications are expected to be self-configuring, self-managing, and self-healing. As the range of permissible configurations grows, this expectation becomes an enormously complex undertaking. Indeed, the management subsystem for a contemporary distributed system (i.e., a Web Services system reporting data collected from a set of corporate databases, file systems, and other resources) is often more complex than the application itself. Yet the technology options for building management mechanisms have lagged.

Current solutions, such as cluster management systems, directory services, and event notification services, either do not scale adequately or are designed for relatively static settings. The aim of this theme is to integrate research efforts in wired and wireless environments within the single framework.

  1. Wired Environments The Internet is composed of large numbers of intranets. The intranet is the preferred enterprise solution for delivering interoperable communications for internal information exchange and also a gateway to the larger Internet. Over recent years these data networks have experienced significant growth in size and complexity resulting in an increase in frequency, type and severity of network problems. To ensure early detection and identification of these problems better network management algorithms and tools must be employed. In the management of large enterprise intranets (e.g. Cloud environments), it becomes difficult to detect and identify causes of abnormal change in traffic distributions when the underlying logical topology is dynamic. Network management techniques use statistical trending methods and visualization tools to monitor network performance. Traditional network management techniques cannot deal with situations in which the network is ‘highly dynamic’ (physical and logical structures of time-varying nature added to traffic variations). This theme will investigate possible applications of: Dynamical systems (discrete, continuous, and hybrid) in modelling the of dynamic communications/information networks, networks of dynamical systems (users are modelled as dynamical systems) in behaviour modelling of time series of communications/information networks, complex systems in modelling of large and dynamic communications/information networks, and computational and statistical mechanics in modelling and behavioural analysis of communications/information networks.
  2. Mobile, Sensor Networks, Mesh Networks and Vehicular Networks These systems have different capabilities and constraints to those in the ‘wired’ world. The connectivity of the underlying network should not change in the absence of communication link or host failure. On the other hand, mobile hosts are capable of moving between different locations while maintaining their connectivity to the network – for example, via a cellular connection or a packet radio network. In standard terminology, a mobile host is an entity capable of communication and of performing “local” computation. This is the main characteristic that differentiates a mobile host from communication-only devices such as pagers or portable terminals.
    Mobility of hosts introduces a new set of issues that were not present in networks and distributed systems with static hosts only. For example, to deliver a message to a mobile host, it is necessary that the current position of the destination host be first identified within the network. As the hosts move, the physical connectivity of the network changes. Hence, any logical structure that many network algorithms exploit – for example, spanning trees, path covers, etc., cannot be statically mapped to a set of physical connection within the mobile network. Mobile hosts have severe resource constraints in terms of limited battery life and, as a consequence, often operate in “sleep” mode, with sporadic bursts of network activity, or entirely disconnected from the network. The communication between a mobile host and the remainder of the network occurs via a wireless medium. Such a medium physically supports broadcast communications within a specified region, commonly referred to as cell. These aspects are characteristic of mobile/wireless computing and have to be considered in the design of algorithms, centralized or distributed, for these networks.