Context: The core technology used in a videoconferencing system is digital compression of audio and video streams in real time. The hardware or software that performs compression is called a codec (coder/decoder). Compression rates of up to 1:500 can be achieved. The resulting digital stream of 1s and 0s is subdivided into labeled packets, which are then transmitted through a digital network of some kind (usually ISDN or IP). The use of audio modems in the transmission line allow for the use of POTS, or the Plain Old Telephone System, in some low-speed applications, such as videotelephony, because they convert the digital pulses to/from analog waves in the audio spectrum range.

Question: What is the software that performs audio and/or video compression?
Answer: a codec (coder/decoder)

Question: How high can compression rates go?
Answer: 1:500

Question: What is one digital network through which a digital stream can be transmitted?
Answer: IP

Question: What does POTS stand for?
Answer: Plain Old Telephone System

Question: What do POTS do?
Answer: convert the digital pulses to/from analog waves

Question: What is the core digital network used in a videoconferencing system?
Answer: Unanswerable

Question: What is the low speed application that performs compression?
Answer: Unanswerable

Question: How high can audio modems go?
Answer: Unanswerable

Question: What is transmitted through low speed applications of some kind?
Answer: Unanswerable

Question: What does an ISDN convert in the audio spectrum range?
Answer: Unanswerable