Testing of interworking between network terminals with FSK receivers and public exchanges providing display and related services

Implementation of new services in the network requires appropriate methods and tools for checking correctness of interworking between terminals and exchanges. In this article the methodology and test procedures prepared for testing terminals handling FSK protocol transmitted over the local loop for display and related services was described. Methodology presented here is based on ETSI standards. Test procedures were developed for services offered in Polish network. Tests cover all levels of FSK protocol. For two lower layers, separate procedures for ^on-hook" and "off-hook" loop states were prepared. The procedure for "on-hook" state contains tests related to data transmission "associated" and "not associated with ringing". These procedures cover normal cases with parameter values and sequence elements complying with standards and exceptional procedures with the extreme values of the parameters and with modified elements of the sequences.