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Re: [tsvwg] OCS option in draft-ietf-tsvwg-udp-options-07

Raffaele Zullo <raffaele@erg.abdn.ac.uk> Tue, 12 March 2019 16:43 UTC

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Date: Tue, 12 Mar 2019 16:43:12 +0000
From: Raffaele Zullo <raffaele@erg.abdn.ac.uk>
To: Joe Touch <touch@strayalpha.com>
Cc: Derek Fawcus <dfawcus+lists-tsvwg@employees.org>, tsvwg <tsvwg@ietf.org>
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Subject: Re: [tsvwg] OCS option in draft-ietf-tsvwg-udp-options-07
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On 2019-03-12 01:41, Joe Touch wrote:
>> On Mar 11, 2019, at 3:18 PM, Derek Fawcus 
>> <dfawcus+lists-tsvwg@employees.org> wrote:
>> 
>> The only use I could see for leaving surplus for non option use
>> would be in the case of there being an option indicating
>> 'the rest of the surplus is X', for some X.
>> 
>> So really what we lose is the ability to have an option of more
>> than 255 bytes

Hello,

To leave it open to Options longer than 255

Why not declare that a Length = 0 means that the 3rd and 4th bytes 
contain the Length of the Option?


> We can easily declare one final option that is “remainder”.
> 
> Note that comes with some caveats:
> - it wouldn’t have a length; like NOP, EOL, and OCS, it would just be a 
> flag.
> - it would not be defined as being included in the OCS (if it were, it
> would be a conventional option IMO), which means any use of that area
> would need to consider a checksum area that can be used like CCO (NOTE


AFAIU

EOL already works as an Option "remainder"

Raffaele Zullo

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