ey scale granularities or - colour with different fidelity levels, for example normal colour (8-bit representa- tion), high colour (16 bit), true colour (32 bit) - resolution represented by pixels/square inch. Normal alternatives are 640x480 (lowest quality), 800x600, 1024x768, 1280x1024 and 1600x1200 (high- est quality). Delay - minimal/low. The delay consists primarily of network propagation delay (which can never be zero), also by buffering, format conversions (e.g. A/D and D/A conversions) and any other type of handling of the information stream. The ITU has in recommendation G.114 specified the following values for one-way delay for voice (telephony): - 0-150 ms - acceptable for most user applications 150-400 ms - acceptable provided that the operators/administrations are aware of the transmission time impact on the transmission quality of the user application - 400+ - unacceptable for general network planning purposes. Voice and pictures must be fully synchronized in video conversations. This means that the above values are also valid for the picture component. Delay variation - none (as perceived by the user). Buffer functions at the receiver side can handle smaller delay variations, but the delay, as described above, increases. Noise - none/low. Service accessibility - no or low congestion is the adequate measure in circuit-switched networks. In packet-oriented networks the effective throughput, measured in bit/s is a more adequate measure (to avoid 'slow' connections). Service availability - high, meaning no or low probability of interruptions of the ser- vice. Bit error ratio (BER) - low or medium depending on application. 5.4.2 STREAMING CLASS Multimedia streaming is a technique used for transferring information such that it can be processed as a steady and continuous stream. Streaming technologies are becoming Understanding Changing Telecommunications - Building a Successful Telecom Business increasingly important with the growth of the Internet because most users do not have fast enough access to dow