The primary problem with computer video is the amount of data that must be transferred over computer networks. The following table shows the amount of data to be transferred in one second for each of the four common computer-mediated conferencing rates. Typical performance is 4.2Kbytes per second. The following table uses 8 bits for color and presents the amount of data needed to be transferred in one second for each of the four common frames rates used in computer-mediated conferencing. This still doesn't make computer-mediated motion viable with common modems over telephone lines.
Most large companies use dedicated computer-mediated conferencing connections.
Data compression may be done with special hardware or software on a computer with good processing capability. Picture segmentation divides a frame into squares and only sends the squares where the image has changed. Data compression has been incorporated into most commercial computer-mediated conferencing systems. Sound presents a different set of problems for computer-mediated conferencing. By cutting off all sounds below 40hz and above 20Khz, the amount of data to be transferred is reduced.