This OS fingerprinting probe sends a number of TCP SYN packets to an open
						port of a remote machine. The Initial Sequence Number (ISN) in each of the
						SYN/ACK response packets is analyzed to determine the smallest number that
						the target host uses when incrementing sequence numbers. This information
						can be useful for identifying an operating system because particular
						operating systems and versions increment sequence numbers using different
						values. The result of the analysis is then compared against a database of OS
						behaviors to determine the OS type and/or version.