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Re: [6lo] draft-ietf-6lo-minimal-fragment-00: When to remove VRB entries?

Carsten Bormann <cabo@tzi.org> Thu, 07 February 2019 11:23 UTC

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From: Carsten Bormann <cabo@tzi.org>
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Date: Thu, 07 Feb 2019 12:23:19 +0100
Cc: Martine Lenders <m.lenders@fu-berlin.de>, 6lo@ietf.org
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To: Yasuyuki Tanaka <yasuyuki.tanaka@inria.fr>
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Subject: Re: [6lo] draft-ietf-6lo-minimal-fragment-00: When to remove VRB entries?
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On Feb 7, 2019, at 11:58, Yasuyuki Tanaka <yasuyuki.tanaka@inria.fr> wrote:
> 
> If you receive a fragment having a fragment_tag which you've already seen and the fragment_tag is not associated with any entry in the VRB table, you can consider it as a duplicate or late-arriving fragment. Then, you can drop the received fragment safely.

That means you need a second table of datagram_tag values “already seen and done” (obviously with a timeout, or maybe with some serial number logic).
Maybe not a bad optimization to handle trailing duplicates.

Grüße, Carsten

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