NETrix: a procedure for the calculation of the network structure and traffic matrix in ATM networks

NETrix is a strategic planning tool which considers a specific client broadband service classification scheme where each service is modelled by a set of values from a service attribute model and the service occupation by corresponding parameter values for each client class. NETrix uses the mean value and its variance of the digital signal stream of the corresponding service for the source traffic description and calculates the total node traffic as the sum of all corresponding source traffic. Nodes are classified by a heuristic algorithm based on the total node traffic and the geographical distance allowing the level of some nodes to be predetermined. This results in a two level network composed of concentrators in the access layer and switching units in the backbone one. The node traffic of each service class is then distributed over this network topology with a corresponding traffic distribution model. This model considers two parameters, geographical distance and traffic volume in the nodes, where the values of the parameter are assigned individually for each service class. As a result of this distribution, NETrix gets the traffic flow over all access and backbone links by considering a star structure for the access network and a full meshed structure for the backbone one. NETrix provides a set of additional procedures to analyse the obtained results in each planning step with a corresponding numerical and graphical representation.