What is back-pressure?
A non-standard but popular scheme called back-pressure was used in half-duplex flow control. If a port is operating at half-duplex, the switch sends a collision to make the transmitting device to wait. So when a half-duplex device wasn’t able to handle the amount of data it was receiving from an end station, it collided with it (faked a collision by sourcing JAM). Thus all devices on the shared LAN would have to back-off, and then try to re-transmit. The device could keep on colliding, so the other end stations will keep backing off.
