Term:CGNAT
Short definition: Network Address Translation performed at the level of the ISP's equipment.
Long definition: Carrier Grade Network Address Translation (CGNAT) is a form of Network Address Translation (NAT) performed at the level of the ISP's equipment. Traditional NAT is performed with a user-managed router, and thus allows port forwarding. Users have no control over the ISP routers used for CGNAT, and thus it precludes port forwarding one's home devices.