The NAT traversal definition:

Answer: Pending

Explanation:
NAT-T (NAT Traversal)
If both peers support NAT-T, and if they detect that they are connecting to each other through
a Network Address Translation (NAT) device (translation is happening), they may negotiate
that they want to put a fake UDP port 4500 header on each IPsec packet (before the ESP
header) to survive a NAT device that otherwise may have a problem tracking an ESP session
(Layer 4 protocol 50).
https://supportforums.cisco.com/document/64281/how-does-nat-t-work-ipsec