IEEE 1284.4-2000

The packet protocol described by this standard allows a device to carry on multiple, concurrent exchanges of data and/or control information with another device across a single point-to-point link. the protocol is not a device control language. The protocol provides basic transportlevel flow control and multiplexing services. The multiplexed information exchanges are independent and blocking of one has no effect on any otherre. The protocol shall operate over IEEE 1284-1994 interfaces and may operate over other point-to-point interfaces.