Here is the inaugural paper on NAT by Paul Francis (formerly Tsuchiya) & Tony Eng in 1993: https://www.cs.cornell.edu/people/francis/tsuchiya93extending.pdf htt

Here is the inaugural paper on NAT by Paul Francis (formerly Tsuchiya) & Tony Eng in 1993: https://www.cs.cornell.edu/people/francis/tsuchiya93extending.pdf https://www.cs.cornell.edu/people/francis/tsuchiya93extendin... A bit different to modern implementations as it relied on DNS.