Patent ID: 7114181
Filing Date: 2006-09-26
Classification: H04L

Abstract:
1. A method of preventing an attack on a network, wherein the attack comprises injecting a spurious transmission control protocol (TCP) segment into a TCP connection between a sender and a receiver, the method comprising the computer-implemented steps of: receiving a TCP segment carrying a sequence value and an ACK value; determining whether the ACK value is less than the difference of a next unacknowledged sequence value and a lesser of either (a) a total number of bytes sent in the TCP connection or (b) a maximum window size associated with the TCP connection; and discarding the TCP segment when the ACK value is less than the difference of a next unacknowledged sequence value and the lesser of either (a) the total number of bytes sent in the TCP connection or (b) the maximum window size associated with the TCP connection.