ll other T.120 application protocols, but no future enhancements will be made to it. The Base Mode is modeled after the Legacy Mode but it makes more extensive use of generic conference control for capabilities negotiation and session management. Physical Data Unit organization and encoding has been brought in line with other T.120 application protocols. The Base Mode will provide the basis for future extensions to T.120's application sharing support. T.SHARE does the following: Provides a protocol for font matching and text exchange Provides a protocol for basic window management Defines a protocol to manage shared pointers Supports compressed bitmap exchanges Supports rectangle, line and frame operations Defines caching policy for bitmaps, pointers, color tables and desktop save areas Defines protocol for the communication of keyboard & pointing device events. T-SHARE has been available on the Macintosh platform, UNIX, and various Microsoft Windows platforms (Microsoft's Remote Desktop Protocol, RDP, is a single-session extension of T.SHARE). Standards for Audiographic Conferencing T.120 FUTURE ENHANCEMENTS T.RES The T.RES is concerned with Reservation Systems. This T.120-oriented set of specifications was designed to simplify the process of reserving a conference across product platforms. Like T.SHARE, T.RES deployment has suffered at the expense of manufacturers who do not necessarily consider cross platform interoperability to be in their interests. It is quite unfortunate. There are four components to RES-T.RES.0, T.RES.1, T.RES.2 and T.RES.3. T.RES.0 provides a reservation system overview. T.RES.1 defines the user-to- reservation system interface. This protocol specifies how user terminals access conference reservation systems. T.RES.2 defines a reservation system-to-MCU interface. T.RES.3 defines a reservation system-to-reservation system interface. T.MT is a set of specifications that are designed to allow Multicast Transport-e.g., to enable the multipoint conference service (MCS) to ride on the top of I