window rule option is used to check that the TCP header window number is less than, greater than, equal to, not equal to, less than or equal to, or greater than or equal to a specified integer value. This rule option can also check that the window number is between a range of numbers, using the
<> range operator for an exclusive range check or the
<=> for an inclusive one.
# Check for a Window size that equals 55808 window:55808;
# Check for a Window size that is between 0 and 55808 (exclusive) window:0<>55808;