-The value is never reset, not even after rekey has been performed. Note
-that the sequence number is incremented only when MAC is computed for a
-packet. If packet is not encrypted and MAC is not computed then the
-sequence number is not incremented. Hence, the sequence number is zero
-for first encrypted packet.
+The value is never reset, not even after rekey has been performed.
+However, rekey SHOULD be performed before the sequence number repeats
+from zero. Note that the sequence number is incremented only when MAC is
+computed for a packet. If packet is not encrypted and MAC is not computed
+then the sequence number is not incremented. Hence, the sequence number
+is zero for first encrypted packet.