Task: Question Generation
Input (English): The company had an IPO on the NASDAQ in 1996 and in 1997 Europe's largest telecommunications company, Deutsche Telekom, bought a 21.1 percent stake in VocalTec for $48.3 million, in addition to purchasing $30 million in telephony products, services, and support over the following two-and-a-half years.
Output (English): What stock exchange is VocalTec associated with?