Re: [Int-area] WG Adoption Call: IP Fragmentation Considered Fragile

Joe Touch <> Wed, 29 August 2018 15:11 UTC

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Date: Wed, 29 Aug 2018 08:11:44 -0700
From: Joe Touch <>
To: Toerless Eckert <>
Cc: Tom Herbert <>, Christian Huitema <>, int-area <>,
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Subject: Re: [Int-area] WG Adoption Call: IP Fragmentation Considered Fragile
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On 2018-08-28 17:24, Toerless Eckert wrote:

> ...Sure, i meant to imply that port-numbers are useful pragmatically,
> but other context identifiers would long term be better. 
> Demux-Identifiers at the granualarity of a subscriber or 
> application wold be a lot more scalable than flow identifiers.

There are many problems with this issue. 

First, the reason that port numbers would be needed is that they are
*currently* how NATs demux, firewalls enforce policy, and routers manage
flows. For each of these, a different identifier could be developed, but
they would not then reduce the need for ALL of these at the IP level at
some boxes. E.g., see draft-touch-tcpm-sno 

Ultimately, we have to admit that a device that acts on behalf of a host
IS a host and costs what a host costs. 

We can't keep believing there is magic dust that can establish a
solution otherwise.