What is TCP Header Prediction?

I am seeing the terms : "TCP acknowledgements with successful header prediction" and "TCP data segments with successful header prediction" in an SNMP MIB I am working with. It seems that certain types of Unix Netstat commands also provide this information. I am fairly knowledgeable about TCP but I am not familiar with these terms. Would appreciate any enlightenment on what "header prediction" is. ## Deliverables 1) All deliverables will be considered "work made for hire" under U.S. Copyright law. Buyer will receive exclusive and complete copyrights to all work purchased. (No GPL, GNU, 3rd party components, etc. unless all copyright ramifications are explained AND AGREED TO by the buyer on the site per the coder's Seller Legal Agreement). ## Platform Windows, Linux