Queueing analysis of nonpreemptive reservation priority discipline

Local area computer network simulations are inherently non-Markovian in that the underlying stochastic process cannot be modeled as a Markov chain with countable state space. We restrict attention to local network simulations whose underlying stochastic process can be represented as a generalized semi-Markov process (GSMP). Using new better than used distributional assumptions and sample path properties of the GSMP, we provide a geometric trials criterion for recurrence in this setting. We also provide conditions which ensure that a GSMP is a regenerative process and that the expected time between regeneration points is finite. Steady-state estimation procedures for ring and bus network simulations follow from these results.

The defining characteristic of a networked control system (NCS) is having a feedback loop that passes through a local area computer network. This paper considers nonlinear systems controlled in this manner, and demonstrates that for sufficiently high transmission rates, the network may be considered transparent. Three methods of scheduling data packets are compared: a static scheduler (token ring), the try-once-discard (maximum-error-first) scheduler with continuous priority levels, and the try-once-discard scheduler with discrete priority levels. The third method is of particular interest when only a small number of bits are available for collision resolution. Asymptotic stability is guaranteed in the first two cases, and ultimate uniform boundedness in the third. In the final section, simulations demonstrate the theoretical results. The contributions of this paper are two-fold: first, it extends the earlier results on NCS to nonlinear systems, and second, it allows for finite word-length message identifiers.

This discussion considers in particular the application of ISDN technology to data processing needs, and gives some practical examples showing when an ISDN implementation in an organisation can be feasible. >

At present, the use of local area computer networks is a common place practice. This allows heterogeneous computers to share information in a more efficient and trustworthy way7,10. Consequently, distributed systems have come about, which allow the use of the most suitable computer for each application. For example, a computer with a mathematic coprocessor might exist, to meet demands of programs which require the heavy use of floating point operations, that could be used remotely, maintaining at the same time the transparency for the user.

A slotted-ring protocol that performs well across the full range of message length distributions is presented. The relative performance of the protocol is best at low to medium ring utilization, which is the most usual operating condition for local area computer networks. The protocol is not subject to the normal requirement for repeating source and destination addresses in each slot of a multiple-slot message. This reduced overhead feature is a main reason for the performance gains that are achieved. The protocol does not depend on any central control station for assigning slot usage to individual stations. However, it does require each ring station to keep track of the current status and source station usage of each slot on the ring. Implementation of the protocol would require significantly more complex logic circuits than are normally needed in either token rings or conventional slotted rings, and error recovery would be more difficult. Hence, its main value is that it serves as an indicator of the maximum achievable performance of the slotted format for local computer network rings operating at low to medium utilization levels under fully distributed access control. >

The object of research in the article are the tools and capabilities of the C# programming language for the implementation of cybersecurity analysis software in local computer networks and computer-integrated systems. The relevance of the study is due to the importance of information security of computer and computer-integrated systems in government, military-industrial complex, private business etc., and due to the importance of training cybersecurity professionals in higher education to consider teaching examples in popular programming languages. The goal of the work is to research the possibilities of the C# programming language for the development of software that analyzes cybersecurity in local computer networks and computer-integrated systems. The tasks to be solved are: to develop software for scanning network device ports in computer networks and computer-integrated systems for information security audit, using tools and libraries of the C# programming language, to research the benefits and possibilities of using this programming language for this task. Research methods: theory of computer networks, object-oriented programming, theory of algorithms and data structures, theory of software testing. Conclusions. In this paper the possibilities and advantages of the C# programming language for developing cybersecurity analysis software for computer and computer-integrated systems were explored. In the course of work software that analyzes information security in local computer networks and computer-integrated systems was developed. This software can be used for educational purposes in learning the C# programming language and cybersecurity of computer systems. The developed software has the potential to be further improved and applied in various fields to test the cybersecurity of local computer networks and computer-integrated technologies.

Simulation of local area computer networks

The purpose of this research is to develop a system that has been running so far by designing and building a Local Area Network computer network on the sales system at Bencoolen Coffee. Sales system at Bencoolen Coffee And Resto is made using Visual Basic .Net programming language and SQL Server 2008r2 database. This Sales System is based on Wireless Local Area Network with 4 access rights to use the application, namely administrator, cashier, chef, and consumer. With this sales system, it can help Bencoolen Coffe And Resto in managing food and beverage data, as well as daily sales that have been integrated into one unit. The sales system at Bencoolen Coffee And Resto is implemented with 5 laptops connected to 1 local network where 1 laptop is used as a server, 1 laptop is used as an administrator, 1 laptop is used as a chef, 1 laptop is used as a cashier, and 1 laptop is used as a consumer, which has different functions. vary. Based on the results of the tests that have been carried out, the functionality of the Sales system at Bencoolen Coffee And Resto runs as expected, and the system is able to carry out data processing within the scope of the Bencoolen Coffee And Resto network.

This paper investigates the solution of the optimization problem that appears in the design of double loop structured local area computer networks or interconnection networks. Double loop structure is a regular, two-connected network, designed for packet communications. The studies of degree two network connection schemes is based on the circular graphs of degree four. These graphs are regular, vertex-symmetric, and maximally connected, and such optimal graph exists for any given number of nodes. Every four of two-connected nodes consists a cluster, so cluster is a component with four input and four output link in the network. The proposed cluster network forms the optimal connection of a circular graph. We demonstrate how to construct one such network for any number of nodes and examine their network properties. The problem of routing is also addressed, and two routing rules are investigated that take advantage of the network regular structure.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

The use of multiple buses can improve both the fault tolerance and performance of local area computer networks. Existing schemes either depend on active components for full connectivity or can experience decreased performance as many hosts attempt to access one bus. An architecture class based on balanced incomplete block designs (BIBDs) is proposed to address these problems. A BIBD architecture uses redundant communication channels and exhibits degradable performance as faults occur. The performability of such networks is evaluated, where evaluation is based on stochastic activity network models. The results obtained are provided for comparison of BIBD network performability with that of conventional multibus networks. >

Local area computer networks for industrial process control: Mataix, J and de la Puente, J AMundo Electronico No 163 (June 1986) pp 57–63 (in Spanish)

Regenerative Simulation Methods for Local Area Computer Networks.

This paper presents a discrete time bulk service queue under the policy (a, c, d) with state dependent service rates. The inter-arrival times are assumed to be independent and geometrically distributed. The customers are served by a single server under the policy (a, c, d) with state dependent service rates. In this model the server begins service only when there are at least c units in the queue and he serves a maximum of d units in a batch. The server continue to serve even when the queue size is less than c but not less than a secondary limit a after a service completion epoch, but with a different service rate. If after a service completion epoch the queue size is less than a, the server becomes idle. The service times are also assumed to be independent and geometrically distributed. The steady state probabilities and some performance measures of the model are computed.

It is argued that over the next 15 years, there should be a quantum increase in the amount of computing power delivered to the user. This paper will be derived from the network to which these devices are connected. While all of this will be of interest to the technologist, there is no focus being given to the application of the power of the local computer network (LCN) to the needs of the users. The LCN is then examined from the viewpoint of what is necessary if the LCN in particular, and computing in general, is to achieve its full capability as a tool for users. >

We consider a multi-class priority queueing system with a non-preemptive time-limited service controlled by an exponential timer and multiple (or single) vacations. By reducing the service discipline to the Bernoulli schedule, we obtain an expression for the Laplace-Stieltjes transform (LST) of the waiting time distribution via an iteration procedure, and a recursive scheme to calculate the first two moments. It is noted that we have to select embedded Markov points based on the service beginning epochs instead of the service completion epochs adopted for most of M/G/1 queueing analyses. Through the queue-length analysis, we obtain a decomposition form for the LST of the waiting time in each queue having the exhaustive service.