An IN (Intelligent Networks) management scheme for ISO Interface is presented in this paper. The interface is for interactions, via services called Input/Output Services, between desktop applications and voice terminals. These services allow computer applications to provide users with enhanced services by exploitation of the characteristics of a variety of telephony device types. This is by interacting with a switch-based software object, called Information-Path, associated with the device that allows input to be received from the device and output to be sent to the device. The management scheme is suitable for multimedia interactive telecommunications. It covers applications that involve only voice calls (ISDN B channel), only data calls (ISDN D channel), and both voice calls and data calls (both ISDN B channel and ISDN D channel). So, it is suitable for multimedia communications that involve voice, data, and graphics. The applicability is demonstrated by applications scenarios that involve multimedia mail.