CGNAT Solutions

Masataka Ohta mohta at
Wed Apr 29 08:05:16 UTC 2020

Brandon Martin wrote:

>> If you mean getting rid of logging, not necessarily. It is enough if
>> CPEs are statically allocated ranges of external port numbers.
> Yes, you can get rid of the logging by statically allocating ranges of 
> port numbers to a particular customer.

And, that was the original concern.

> What I was referring to, though, was the programmatic state tracking of 
> the {external IP, external port}-{internal IP, internal port} mappings.


>   You can't eliminate that unless the CPE also knows what internal port 
> range it's mapped to so that it restricts what range it uses.  If you 
> can do that, you can get rid of the programmatic state tracking entirely 
> and just use static translations for TCP and UDP which, while nice, is 
> impractical.  You're about 95% of the way to LW4o6 or MAP at that point.

Interesting. Then, if you can LW4o6 or MAP, you are about 95% of the
way to E2ENAT with complete end to end transparency using IPv4 only,
which means we don't need IPv6 with 4to6 NAT lacking the transparency.

						Masataka Ohta

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