The continued growth in subscriber networks and private carriers has led to an increased demand in test equipment in the telecommunications market. Protocol analyzers, instruments used for network management and trouble-shooting, are in especially high demand, according to a report issued by Frost & Sullivan of Mountain View, Calif., an international marketing consulting company. As private carriers continue to upgrade their networks by installing new technologies such as fiber optics, the need to test and measure performance parameters increases proportionately. Therefore, Frost & Sullivan projects strong growth for the next few years. Overall, revenues for the industry reached $841 million in 1996.