Tasho D. Tashev

Modeling of the hotspot load traffic for crossbar switch node by means of Generalized Nets

The apparatus of Generalized Nets is applied here to describe a PIM-algorithm for computing a non-conflict schedule for packet switch node. In the present paper we propose a family of patterns for nonuniform traffic simulation based on the hotspot traffic model. The results from computer simulations of the throughput on a switch node with these patterns are presented. The necessary computations have been performed on grid-clusters of CERN. Our simulations utilize the PIM-algorithm, specified by apparatus of Generalized Nets. It is shown that there is an upper bound on the throughput of PIM-algorithm for proposed family of patterns.

Large-Scale simulation of uniform load traffic for modeling of throughput on a crossbar switch node

In the present paper we propose a family of patterns for uniform traffic simulating. The results from computer simulations of the throughput on a switch node with these patterns are presented. The necessary computations have been performed on grid-clusters of IICT-BAS and CERN. Our simulations utilize the PIM-algorithm for non-conflict schedule, specified by apparatus of Generalized Nets. It is shown that the usage of the suggested family of patterns enables us to evaluate the influence of large scale changes of the input buffer on the throughput.

Computering simulation of schedule algorithm for high performance packet switch node modelled by the apparatus of generalized nets

The aim of the paper is a check of the capability of Generalized nets (GN)apparatus for modelling of parallel processes in packet switch node. By means of Generalized nets is synthesised a model of PIM (Parallel Iterative Matching) algorithm for computing of non-conflict schedule in crossbar switch node. The results of computer simulation of a GN-model performing uniform load traffic are presented. It is shown that so obtained by the simulation evaluation for throughput of switch mode tend near the theoretical boundary. A simple model for uniform traffic is suggested for switch throughput calculating which is capable to estimate approximately but faster at a rate depending on the rank of switch.

An algorithm of non-conflict schedule with joint diagonals activation of connectivity matrix

A synthesis of an algorithm for non-conflict schedule with joint diagonals activation is done. A software model of the algorithm is built. Rapidity, performance and memory resources are analyzed. It is calculated the performance and memory resource for different switching matrix types and sizes. A comparison of the proposed algorithm with other algorithms for non-conflict schedules is done.

A Numerical Study of the Upper Bound of the Throughput of a Crossbar Switch Utilizing MiMa-Algorithm

In the present paper we propose a family of patterns for hotspot load traffic simulating. The results from computer simulations of the throughput of a crossbar packet switch with these patterns are presented. The necessary computations have been performed on the grid-cluster of IICT-BAS. Our simulations utilize the MiMa-algorithm for non-conflict schedule, specified by the apparatus of Generalized Nets. A numerical procedure for computation of the upper bound of the throughput is utilized. It is shown that the throughput of the MiMa-algorithm with the suggested family of patterns tend to 100 %.

A simulation study of the throughput of a crossbar switch node by means of periodic input patterns

In this paper a simple model for uniform traffic with periodic input patterns is suggested. Periodic input patterns (PI-Patterns) represent a further development of the family of patterns (S-Patterns) proposed in our previous investigations. Our simulation studies use the Generalized Nets (GN) model of the known PIM-algorithm. The simulation results of a GN-model using PI-Patterns are presented and compared with results obtained for S-Patterns. It is shown that the upper bound for the throughput of PIM-algorithm for the S-Patterns is the value of throughput for uniform traffic with PI-Patterns.

A study of modeling precision of an algorithm for crossbar switch node under scientific Linux SL release 5

Achieving maximal throughput of a crossbar switch depends on creation of non-conflict schedule for packet commutation. The first step in checking the efficiency of commutation is throughput modeling of the switch by uniform demand traffic. In this paper we study the dependence between uniformity of the output sequences of a pseudo-random numbers generator and the required number of simulations to achieve a specified precision for this type of traffic under Linux SL with CERN-grid. The relationships have been obtained through computer simulated commutation using Generalized Nets model of the known PIM-algorithm. A possibility is shown for one to choose between precision and number of simulations.

High Performance Computations for Study the Stability of a Numerical Procedure for Crossbar Switch Node.

In the present paper the problem concerning computation of the upper bound of the throughput (THR) of crossbar switch node is formulated. The task is solved using an appropriate numerical procedure. The input data for this procedure are the results of high performance simulations executed on the grid-structure of the IICT-BAS (www.grid.bas.bg). The modeling of the THR utilizes MiMa-algorithm for a node with \((n\times n)\) commutation field, specified by the Generalized Nets. For studying the stability of the numerical procedure we use a modified family of patterns for hotspot load traffic simulation. The obtained results give an upper bound of the THR for \(n\in [3,97]\) which enables us to estimate the limit of the THR for \(n\rightarrow \infty .\) This estimate is obtained to be \(100\%\) for the applied family of patterns. The numerical procedure is stable (small input perturbations lead to small changes in the output).

Modeling of the MiMa-algorithm for crossbar switch by means of Generalized Nets

The Generalized Nets apparatus is applied here to describe the MiMa-algorithm for computing a conflict-free schedule for packet switch. In the paper we propose a family of patterns for nonuniform traffic simulation. The results for throughput on a switch node with MiMa-algorithm by computer simulations with these patterns are presented. The necessary computations have been executed on BG01-IPP grid-cluster (www.grid.bas.bg) of the Institute of information and communication technology (IICT-BAS). It is shown that the upper bound on the throughput of MiMa-algorithm is committed to 100% (maximal throughput) for the proposed family of patterns.

Computer simulations of a modified MiMa-algorithm for a crossbar packet switch

The paper presents computer simulations of an algorithm for non-conflict packet commutation in a crossbar switch node. In particular, we study a version of the MiMa-algorithm with a new selection of the initial element of the traffic matrix as compared to the original version of the algorithm. Our simulations utilize independent, identically distributed (i.i.d.) Bernoulli uniform load packet traffic. The obtained results indicate that the original MiMa-algorithm yields better results with respect to the throughput of the crossbar switch in comparison to the modified version.