Re: Experimental RFC to be: draft-stoica-diffserv-dps-01.txt

[Bill Fenner <fenner@research.att.com>]

>This can happen only if the eggres node of a DPS domain
>"forgets" to reset the ip_off value to zero and update the IP checksum.
>But this is a very simple operation, and I don't see many ways one 
>can get it wrong! 

Ion,

  One of the big problems in router software architecture is
configuration and its complexity.  Mark Handley made a good analogy --
today's router configurations are mostly like programming a processor in
hex.  You have to get everything right, and you have to consider
everything individually.  You don't even get functions or macros.
Therefore, consider that routers probably won't be configured "This
router is a DPS domain border", rather perhaps "perform the DPS domain
border functionality on packets of this type" or even "Zero out the
ip_off field on these packets".  It's easy to imagine some important
bit of the configuration being forgotten.

  Bill