DATA COMMUNICATIONS SYSTEM

摘要

A data communications system comprises a number of interconnected nodes. Messages from the nodes are grouped into frames, and the frames are delivered to all the nodes in the same sequence. Whenever a transmission error is detected, all the nodes co-operate to replay the sequence of frames from a particular point which is at least far enough back to ensure retransmission of the earliest frame that could have been in error. Each node then discards all repeated frames that it has already correctly received.