Using of post selection delay for evaluation of mixed communication network traffic properties

The key indicator of telephone connection setup speed is Post Selection Delay (PSD). The analysis of PSD in telephone networks and its characteristics is performed. Due to differences in transmission of address information in classic and new telephone networks, conditions dealing with the PSD are not same. This conclusion is formulated in the proposition for changing existing target values related to modern packet networks. In addition, the possibility of using PSD in mixed telephone network of Electric Power Utility for monitoring the network operation is described. In such network, different signalling systems i.e. different durations of PSD can be used for checking of proper operation of the network parts and detection of faulty connections.