What is Google's networktraversal service?

Question

Google

I get this error code I copied from another site. What is ha google service? As I understand this key is not suitable for my site, where can I get it?
https://networktraversal.googleapis.com/v1alpha/ic... 403


This is a response from the server

Answer 1

NAT Traversal (NAT-T) is a protocol that encapsulates the traffic of a VPN connection running over protocols such as IPSec or PPTP by creating UDP packets. Outgoing UDP packets are forwarded by a router implementing NAT Traversal over the Internet without any consideration of their content. To do this, NAT-T places an additional UDP header before the IPSec packet so that it is treated as a regular UDP packet throughout the network and the recipient host does not perform any integrity checks. After the packet arrives at its destination, the UDP header is removed and the data packet continues on its way as an encapsulated IPSec ESP packet or GRE packet, providing a PPTP connection. Thus, using the NAT-T technique, it is possible to establish communication between IPSec clients in secure networks and public IPSec hosts through firewalls [1].

https://ru.wikipedia.org/wiki/NAT_traversal
Google Cloud NAT:
https://cloud.google.com/nat
https://cloud.google.com/nat/docs/overview
https://cloud.google .com/nat/docs/using-nat