Overview of NAT64

Definition

Network Address Translation IPv6-to-IPv4 (NAT64) is a technique that translates IPv6 network addresses into IPv4 network addresses.

Purpose

NAT64 applies to the latter phase of IPv6 transition in which IPv6 is the mainstream application. New IPv6-only end users connected to an IPv6 network can access remaining IPv4 services across the IPv6 network.

Currently, IPv4 takes the lead. Carriers deploy IPv6 networks and use NAT64 to allow new users connected to an IPv6 network to access IPv4 services. NAT64 applies to the following situations:

Carrier networks are experiencing IPv4 address shortages or inappropriate IPv4 address allocations, and therefore, fail to meet access requirements of a large number of new users.
Carriers want to phase out IPv4 networks by replacing them with IPv6 networks to implement a smooth transition from IPv4 to IPv6. For example, carriers deploy IPv6 on access and core networks and allow all new users to access IPv6 networks while allowing existing IPv4 users to gradually transition to IPv6 networks.
Emerging carriers directly deploy IPv6 networks to reduce costs.
Mobile phones do not support the IPv4/IPv6 dual stack because of high power consumption and poor heat dissipation. During the transition from IPv4 to IPv6, mobile phone users may need to access IPv4 services across IPv6 networks.

Benefits

NAT64 offers the following benefits to carriers:

NAT64 is future-proof and fundamentally solves deployment difficulties and high maintenance cost issues stemming from the existing IPv4 address insufficiency, which facilitates network evolution towards the IPv6-only transition.
NAT64 is easy to deploy and use. Carriers assign IPv6 addresses, without maintaining IPv4 addresses.
NAT64 address translation prevents internal networks from external attacks, improving security.