The Dutch interbank computer network

At the end of 1980, a strategic decision was made by the Dutch banks and savings banks to commence the development of a Data Communications Infrastructure (DCI), to be used for a number of forthcoming interbank applications. It was agreed that this new data communications infrastructure should be based on the emerging Reference Model for Open Systems Interconnection (OSI). The first interbank application using the DCI (i.e. urgent money transfers) was introduced in the second quarter of 1985. Other interbank applications, which will also make use of the functions provided by the DCI, are currently being developed.\ud \ud This paper provides the background to the DCI project, discusses the selection of OSI standards for the network, and gives an overview of the design of the software package, which was developed to support the selected OSI standards

The one-way quantum computer - a non-network model of quantum computation

A one-way quantum computer works by only performing a sequence of one-qubit measurements on a particular entangled multi-qubit state, the cluster state. No non-local operations are required in the process of computation. Any quantum logic network can be simulated on the one-way quantum computer. On the other hand, the network model of quantum computation cannot explain all ways of processing quantum information possible with the one-way quantum computer. In this paper, two examples of the non-network character of the one-way quantum computer are given. First, circuits in the Clifford group can be performed in a single time step. Second, the realisation of a particular circuit --the bit-reversal gate-- on the one-way quantum computer has no network interpretation. (Submitted to J. Mod. Opt, Gdansk ESF QIT conference issue.)Comment: 7 pages, 3 figure

Computer Network Connecting with the Personal Computer (Pc)

Skytel operations in Indonesia have access to data located in several separate cities,namely Jakarta, Bandung, Semarang, Surabaya, Denpasar and Medan. At the headoffice (Jakarta) terdapt two backbone, where a backbone is used to addressoperational problems (sending information) and the backbone, the other is used tohandle the administration. Each branch office is connected to one backbone, only thecentral office, which handles the operational backbone only, while the backbone thathandles all administrative issues held by the central office. In order for the localnetwork can access the branch office network backbone system of localadministration head office or vice versa, then the media needed to be able to connectthe computer networks of two or more of these. In this case the media is a computernetwork connecting Personal Computers (PCs) which are set as a router using theUNIX operating system

Sonification of Network Traffic Flow for Monitoring and Situational Awareness

Maintaining situational awareness of what is happening within a network is challenging, not least because the behaviour happens within computers and communications networks, but also because data traffic speeds and volumes are beyond human ability to process. Visualisation is widely used to present information about the dynamics of network traffic dynamics. Although it provides operators with an overall view and specific information about particular traffic or attacks on the network, it often fails to represent the events in an understandable way. Visualisations require visual attention and so are not well suited to continuous monitoring scenarios in which network administrators must carry out other tasks. Situational awareness is critical and essential for decision-making in the domain of computer network monitoring where it is vital to be able to identify and recognize network environment behaviours.Here we present SoNSTAR (Sonification of Networks for SiTuational AwaReness), a real-time sonification system to be used in the monitoring of computer networks to support the situational awareness of network administrators. SoNSTAR provides an auditory representation of all the TCP/IP protocol traffic within a network based on the different traffic flows between between network hosts. SoNSTAR raises situational awareness levels for computer network defence by allowing operators to achieve better understanding and performance while imposing less workload compared to visual techniques. SoNSTAR identifies the features of network traffic flows by inspecting the status flags of TCP/IP packet headers and mapping traffic events to recorded sounds to generate a soundscape representing the real-time status of the network traffic environment. Listening to the soundscape allows the administrator to recognise anomalous behaviour quickly and without having to continuously watch a computer screen.Comment: 17 pages, 7 figures plus supplemental material in Github repositor

Signatures of small-world and scale-free properties in large computer programs

A large computer program is typically divided into many hundreds or even thousands of smaller units, whose logical connections define a network in a natural way. This network reflects the internal structure of the program, and defines the ``information flow'' within the program. We show that, (1) due to its growth in time this network displays a scale-free feature in that the probability of the number of links at a node obeys a power-law distribution, and (2) as a result of performance optimization of the program the network has a small-world structure. We believe that these features are generic for large computer programs. Our work extends the previous studies on growing networks, which have mostly been for physical networks, to the domain of computer software.Comment: 4 pages, 1 figure, to appear in Phys. Rev.