 The success of ISACOMM in winning customers away from AT&T, at the same time that MCI and Sprint were doing likewise, provided confirmation that open competition in the long-distance market was viable.Beyond voice and data services, ISACOMM became a leader in videoconferencing by installing videoconferencing rooms around the country, initially using the SBS network for connectivity and subsequently using its own earth station network.ISACOMM engineered each room and provided a centralized reservations facility.