The selected problems of functional testing the ISDN multifunctional terminals

Implementing the PPP protocol in ISDN networks results in widening the range of services offered in these networks, but it also creates the necessity to identify principles of co-operation for the ISDN-Internet interface. These principles are in turn required for verifying correctness of ISDN network terminals operation. The Paper presents the overviews of current state of standardising European ISDN networks taking into account their co-operation with the PPP protocol. It contains selected issues on testing multi-functional ISDN network terminals using the PPP protocol for accessing the Internet network. It presents also the suggested methodology for conformance tests verifying cooperation of ISDN devices using the PPP protocol.