NAT64 port allocation is triggered when a NAT64 device receives the first valid IP packet from an IPv6 terminal.
Dynamic port allocation, also called port dynamic mode, enables a NAT64 device to assign a port number each time a session table is created. Dynamic port allocation maximizes the use efficiency of public IPv4 addresses and ports and is applicable when a few public IPv4 addresses are available. Dynamic port allocation supports interface multiplexing. When receiving packets destined for different public IP addresses, a NAT64 device can map the private IP addresses and port numbers to the same public IP address and port number, respectively, which saves public IP addresses.