Dial Up Modem Sounds After Connecting: Courier HST
This is a companion video to the first Courier HST video: • Dial Up Modem Sounds: US Robotics Courier ...
This time the audio continues after the connection is established, letting you hear what is going on once the speaker turns off.
Courier HST is an asymmetrical protocol, where one direction runs at a much higher speed than the other. In this case of this call, it's 16800/450. Since the rates are so different, there is a clear difference in the tones that can be heard from each side. While the speeds can 'swap' during a call under certain circumstances, in general this was intended for fast downloading, which is why the calling (left) channel is much more muted than the answering (right) channel.