[ih] The invention of what we now call NAT

[Brian E Carpenter]

On 24-Apr-25 07:57, Scott Bradner via Internet-history wrote:
> in RFC 1631 Paul credits Van for "address reuse"
> 
> Acknowledgments
> 
>     This memo is based on a paper by Paul Francis (formerly Tsuchiya) and
>     Tony Eng, published in Computer Communication Review, January 1993.
>     Paul had the concept of address reuse from Van Jacobson.

That was (given publication delays) ~simultaneous with US patent #5371852 filed October 14, 1992. The inventors on that patent were Clement R. Attanasio and Stephen E. Smith, who I'm guessing were both at IBM Poughkeepsie. There's a lot to unpack in the patent, and some interesting prior art, but there's definitely NAT in there. I guess it was just another case of great minds thinking alike.

IBM never disclosed this patent to the IETF. But NAT wasn't on the standards track. If it had been, there would have been a disclosure (because I would have made it happen).

    Brian


> 
>> On Apr 23, 2025, at 3:50 PM, Noel Chiappa via Internet-history <internet-history at elists.isoc.org> wrote:
>>
>>> From: Craig Partridge
>>
>>> I'm working from memory for the most part, so flaws may exist.
>>
>> Ditto.
>>
>>> Van Jacobson is credited as the initial thinker about NAT
>>
>> I have him in memory as the co-inventor, along with Paul Tsuchiya. Not
>> partners, mind - independent inventors.
>>
>> I don't recall why Paul was working in that area (NAT is something I never
>> had much time for - among other things, it makes the network more brittle, by
>> moving state into the end routers - clearly a hack - even more so than BGP -
>> so the details have been GC'd from my memory) - if he's still with us, and
>> someone is in touch with him, they should ask him.
>>
>>> Van came up with NAT as a concept while serving on the ROAD WG
>>
>> IIRC, there was a ROAD meeting on the West Coast (not as part of an IETF),
>> and that was were Van introduced his to us. But I had heard of Paul's before
>> that.
>>
>> I think I still have my email from that era, squirreled away somewhere. I'm
>> not up to looking, though.
>>
>> Noel
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>