The simple testing of analog plain old telephone service (POTS) is no longer sufficient to meet the needs of service providers in this era of profound technological change and increased competition. The need to reduce network maintenance costs while exceeding customers' expectations, as well as to deal with growth and protect the outside plant investment, is critical to every provider's business. The wide range of new services has resulted in an extraordinary growth in data transmissions, and industry estimates forecast this growth rate to continue. The inability of any provider to deal cost-effectively with these multiple challenges is expected to cause many customers to defect.

For years, line testing was primarily used to isolate direct current (DC) faults and to restore service. Now, with increased competition and the proliferation of new technologies, many service providers—incumbent local exchange carriers (ILECs) and competitive local exchange carriers (CLECs) alike—are using line testing to achieve additional business objectives, such as to improve maintenance, reduce customer complaints, qualify lines to offer higher revenue-generating services, enhance customer satisfaction, safeguard outside plant investment, and plan for growth.

The Old Line Testing Model

In the past, relatively uncomplicated tests were sufficient to meet providers' needs, because most tests involved the evaluation of standard POTS traffic—analog signals—on standard telephone lines. Though certain customers required specially conditioned lines in order to send data, faxes, or other types of nonvoice transmissions, these lines represented a relatively small and easily maintained part of service-provider infrastructure. Today's focus on sophisticated line testing in order to cope with more complex challenges marks a dramatic change.

Testing and the Growth of Nonvoice Calls

Several new developments have forced a reevaluation of traditional testing methods for both ILECs and CLECs. In addition, the number of data, point-of-sale terminations, fax, and other types of nonvoice calls has increased dramatically. In some parts of the country, these calls represent more than 50 percent of all service-provider call originations. Accompanying the growth of such calls has been a shift in customer expectations about nonvoice services; today, customers expect to be able to use the same line for voice and nonvoice calls. This development in particular has important implications for the type of maintenance needed on these lines.

It has been estimated that by the year 2002, 75 percent of all service-provider transmissions will be nonvoice. To both handle these calls and meet business objectives, it will be critical that providers have an easy, accurate, and reliable way to test both the voice and nonvoice capabilities of their lines.

The New Line Testing Paradigm

Today, in addition to detecting and correcting problems involving traditional analog traffic, providers need the ability to prequalify lines for ISDN as well as detect improper load coils or noise on lines used for modem traffic. In fact, the changes in testing requirements are so great that a new line testing paradigm is beginning to emerge.