ISDN Telephony OCX is an ActiveX control for adding telephony support to your applications. ISDN Telephony OCX allows you to: answer incoming phone calls or write them to an answering machine\; retrieve the incoming call type, such as fax, phone, or video conference\; receive the call audio format of either ISDN a-law or u-law\; receive the caller number and called number\; store incoming audio data in a file\; play back audio data from file over a connection, disconnect on demand\; and more. It also gives you the ability to receive and listen for DTMF dialtones from the other call party\; receive CAPI version information, manufacturer and serial number\; update computer time to network time during a call\; receive ISDN controller info\; and receive ISDN and CAPI supported supplementary services.