Deterministic NAT allows to eliminate the need for logging because in this mode the subscriber's IP address is always mapped to the same external IP and port range.
Algorithmic Allocation of IP addresses in terms of Deterministic NAT. The Public IPv4 address
and Port range for a given end user are fixed. Once the port range is determined, the allocation of a given port for a new flow is performed dynamically.
As a result, users keep the same public address all the time, there is a lower ratio of Users/Public address, and no log messages needed at all.
Deterministic NAT is one of NFWare vCGNAT