Network integration testing: concepts, test specifications and tools for automatic telecommunication services verification

摘要

The purpose of this tutorial is to provide concepts and historical background of the “network integration testing” (NlT) methodology. NIT is a “grey box” testing technique that is aimed at verifying the correct behaviour of inter- connected networks (operated by different operators) in provisioning services to end users, or the behaviour of a complex network operated by a unique operator. The main technical concepts behind this technique are presented along with the history of some International projects that have contributed to its early definition and application. European Institute for Research and Strategic Studies in Telecommunication (EURESCOM) has actually been very active, with many projects, in defining the NIT basic methodology and providing actual NIT specifications (for narrow-band and broad-band services, covering both voice and data). EURESCOM has also been acting as a focal point in the area, e.g., encouraging the Industry in developing commercial tools supporting NIT. In particular, the EURESCOM P412 project (1994--1996) first explicitly defined the NIT methodology (the methodological aspects include test notation, test im- plementation, test processes, distributed testing and related co-ordination aspects). P412 applied the methodology to ISDN whilst another project, P410, applied NIT to data services. The P613 project (1997--1999) extended the basic NIT methodology to the broad band and GSM. More into details, the areas covered currently by NIT test specifications developed by EURESCOM projects include N-ISDN, N-ISUP, POTS, B-ISDN, B-ISUP, IP over ATM, ATM/FR, GSM, focusing also on their “inter-working” cases (e.g., ISDN/ISDN, ISDN/GSM, etc.). ETSI, the European Tele- communication Standards Institute, also contributed to NIT development (e.g., the definition of the TSP1+ protocol, used for the functional co-ordination and timing synchronisation of all tools involved in a distributed testing session). The paper also discusses NIT in relation to the recent major changes (processes) within the telecommunication (TLC) community. Beyond the new needs coming from the pure technical aspects (integration of voice and data, fixed mobile convergence, etc.) the full deregulation of the TLC sector has already generated new processes and new testing needs (e.g., Interconnection Testing) that had a significant influence on the methodology. NIT is likely to continue to develop further in the future according to the needs of telecom operators, authorities, user's associations and suppliers.