A method and apparatus for controlling data flow across a network performs
a method which includes transmitting a packet request message from a
first station to a second station, then determining if the packet request
message is valid. A request acknowledge message is transmitted from the
second station to the first station, and it is then determined if the
request acknowledge message is valid. The packet request message and the
request acknowledge message each includes a control bit string, an
identification bit string, and at least one parity bit.