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The go-ahead ring the Token Ring LAN is the standard report of type of consecutive management of access to services and services of the local computer network. In this report the signal of the permission of the transfer, named a marker, circulates between the knots placed on a contour of a ring. The knot having the data for transfer, carries out employment of the released marker and will transform it to the occupied marker which transfers a package of the data about its destination. After the package of the data has been accepted by the destination party, the marker comes back to the proceeding knot specified as generating party where it is released again and starts to circulate again on a circle. It is necessary to get acquainted with model of the "going" server, to be able to define structural parametres (average value and a dispersion of time of a course, employment of knot and server employment, time of a cycle and the general time of a course on a ring). Here it is necessary to give special attention to types of clearing of a marker and features of calculation of an indicator of quality of work (symmetric and asymmetric systems) go-ahead ring.
At calculation of an indicator of quality (an average waiting time for knot j) asymmetric (diverse conditions of transportation on knot) systems through course time the big expense of machine time is required. Therefore receive the formula of approximation of an average waiting time by introduction of time of vacation (a time interval between visitings of the same knot j) "the going" server.
Plural access with poll bearing and CSMA/CD LAN resolution of conflicts is the standard report of type of parallel management of access in the conditions of competitions on the general tyre of the local computer network. According to this report the knot having a package, transfers it after acknowledgement of an inactive condition of the general tyre, without having found out bearing on it. Thanks to a delay of distribution bearing, however, there is a conflict possibility. If it happens, clashing knots relay packages after predetermined time. Such procedure is called as operation (back-off) supports of the interrupted communication.
At calculation of an indicator of quality (an average waiting time for knot j) define the sum of average time of access thanks to the mechanism of management of access of CSMA/CD and a waiting time to turns on knot j type M/G/1. At calculation of last component the estimation of a population mean and the second moment of the first component for knot j is required.
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