Means of analysis of the efficiency of the digital commutation system ES-11 with the LAPD protocol

When developing software for implementation of signaling protocols, it is necessary to define a number of parameters. Final values of these parameters are defined at the stage of working software testing based on statistical data about the work of the digital commutation system. The report presents means for development and analysis of the Markovian model of the LAPD (link access procedure on the D-channel) protocol, which is a part of the interoffice signaling protocol DSS-1 (Digital Subscriber Signaling) of the digital commutation system ES-11. These means include: (1) Structural-automatic model of the LAPD protocol. The model represents main procedures of flow control such as frame receiving, frame requery, passing frames for processing to the level 3 procedures according to the OSI model. (2) Program module for solving tasks of investigation of the LAPD protocol procedures. This program module automates the following stages of development and analyses the Markovian model: building the states and transitions graph, forming and solving the Kolmogorov-Chapmen set of differential equations, determining and representation of efficiency indices of the digital commutation system.