ations, particularly VBR (variable-bitrate) video, are very bursty in nature and can temporarily consume network bandwidth and penalize other users of the resource. It seems to be a general observation of the Internet that those causing congestion are not necessarily the ones who suffer from packet loss. Video Transmission A generic list of tasks to transmit multimedia over a network includes compression, traffic control, packetization, multiplexing, and QoS (Quality of Service) control. Compression mechanisms, as discussed previously, reduce the quantity of information transmitted, albeit increasing the value of each bit. Traffic control is where the source controls the bitrate generated by the codec, adjusting the rates according to available channel capacity (Bolla et al., 2000). The coding process adjusts the quantizer step size, frame rates, picture size, and SO forth, according to the pre- scribed budget. Video Transport over the Internet The resulting bitstreams from the codec are placed into packets, which are then fed via a socket to the network. The policy adopted in the packetization will affect the performance of the media. Placing a large amount of data in a single packet makes for good utilization of resources (with the addressing overheads being proportionately small), but a single packet loss results in a considerable loss of data. Conversely, constructing small packets reduces the impact of loss but at the expense of poor network utilization; the addressing mechanism is larger now as a proportion of the packet. Multiplexing refers to time sharing within the Internet. This can occur at the source, where, for example, audio, video, and hypertext are transmitted simultaneously using only a single network socket. It also occurs at network forwarding nodes, which have to multi- plex multiple sources to a single connection. QoS is a general term referring to the way in which some datastreams can be provided with higher priorities than others. This is almost universally employed at the input buffers of 