In the Field Trial there was the the requirement of bidirectional voice connection between PC4 and PC1. This was accomplished using a simple Visual Basic application and Microsoft NetMeeting ActiveX object. On startup the VB Application reads a text configuration file with the address of the remote machine (IP format or machine name) and instantiates a NetMeeting ActiveX object. The object raises events when a connection is received or broken, the VB application shows this changes on the user interface. The only button available is used to connect to the remote machine if we are not already connected, or to hungup the connection otherwise.

There is no need for an answer call button because the "Automatically Accept Calls" was pre-selected on NetMeeting installation.