Re: Where we stand and where we are going

Erik Nordmark <Erik.Nordmark@sun.com> Thu, 04 July 2002 12:58 UTC

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Date: Thu, 04 Jul 2002 14:56:19 +0200 (CEST)
From: Erik Nordmark <Erik.Nordmark@sun.com>
Subject: Re: Where we stand and where we are going
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> I have had two instances where the usage profile of a protocol suggests
> that 99% of the responses will be less than 2K and the interaction is
> stateless and connection-less. Inheriting the full session semantics of TCP
> isn't required. But neither is the sad state of UDP packet size limitations.

Do we know enough about security (starting at what threats need to be
considered  etc) to have any idea what security would do to the packet sizes?

> My proposed solution is to limit UDP packet sizes to 512 bytes and put
> packet sequence numbers on them. You still have a connectionless interaction
> but it a) puts the packet size into a realm with a higher probability of
> success and b) allows for a handful of those packets to get through. I'm
> not sure if you need more than that. You can still do the "well if 
> that didn't work I can always do TCP"...

512 for IPv4 might make sense, but IPv6 can handle more with its 1280 min MTU.
In practise both can handle 1k well in today's network.

If there was a way for the client to predict the size (assuming the problem is
with large replies and not large requests) then life would be better
than an error causing a TCP retry.

  Erik