Re: [Roll] 'S' field in MPL Options

"Jonathan Hui (johui)" <> Thu, 22 November 2012 01:06 UTC

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From: "Jonathan Hui (johui)" <>
To: Dario Tedeschi <>
Thread-Topic: [Roll] 'S' field in MPL Options
Date: Thu, 22 Nov 2012 01:06:15 +0000
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Subject: Re: [Roll] 'S' field in MPL Options
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The question is whether we want to allow sub-TLVs in the MPL Option.  A future specification could introduce sub-TLVs, but that would not be backwards compatible if we did not have an explicit length for the seed-id.  Given the small namespace for IPv6 Options, we might want to consider having a way of including additional fields that is backwards compatible.

Jonathan Hui

On Nov 21, 2012, at 5:00 PM, Dario Tedeschi <<>> wrote:

I agree

The 'S' field seems redundant, because an implementation would still need to read the Length field so it can make sure the 'S' field wasn't lying.

- Dario

On 21/11/2012 10:09 AM, Robert Cragie wrote:
Referring to section 4.1 - maybe I'm missing something but why is the 'S' field needed? Given that the text for Opt Data Len is wrong (it should say "Length of the Option Data field in octets.  MUST be set to 2, 4, 10 or 18"), surely Opt Data Len is sufficient for working out which Seed IDs are in there?


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