PAWS: Protection against wrapped sequence numbers
Largest receiver window = 2^30 = 1 GB
“Lost” segment may reappear before MSL, and the sequence numbers may have wrapped around
The receiver considers the timestamp as an extension of the sequence number => discard out-of-sequence segment based on both seq # and timestamp.
Reqt: timestamp values need to be monotonically increasing, and need to increase by at least one per window