to bridge through an H.323 gateway to conference with systems connected to packet-switched LANs and WANs (and vice versa). The H.323 standard is designed to facilitate point-to-point, multipoint, and broadcast calls among compliant LAN-, ISDN-, and room-based video communication systems. H.323 also supports T.120, which provides a standard means of communication for collaborative tools such as whiteboard applications. Standards-compliance does not preclude systems from shipping with a high-quality proprietary compression algorithm for connections between homogeneous systems. Moreover, for connections between like systems, proprietary compression techniques Video Communications: The Whole Picture usually deliver superior results. When the justification for a system is intra- organization use, standards may be less important than optimal quality. Nevertheless, standards capability is mandatory. Group systems should offer automatic handshaking between codecs (to find the best compatible algorithm). It is not acceptable to ask an end user to fumble through the process of finding a coding technique that is common to both (all) systems. In H.320 systems, the H.221 protocol performs this task. Successful implementations of H.221 can be tricky. It is widely acknowledged as the standard within the H.320 family that is the most difficult to implement, because it is the most complex. PICTURE RESOLUTIONS Picture resolution is a major differentiation between group systems. Resolution is the number of horizontal and vertical pixels that comprise a frame of video. Because pixels are spread over a smaller space, a smaller monitor provides better resolution. Although image clarity is, to a limited degree, determined by screen size, it is far more dependent on the processing techniques the codec uses to format the picture. The H.320 recommendation, specifically the H.261 codec specification, sets forth standards-based image resolutions, CIF and QCIF. The QCIF image format delivers resolutions of about 26,000 pixels-per-screen. CIF