Re: [IPFIX] Interpretation of sequence number handling

Brian Trammell <ietf@trammell.ch> Fri, 19 June 2015 08:39 UTC

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From: Brian Trammell <ietf@trammell.ch>
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Date: Fri, 19 Jun 2015 10:39:10 +0200
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To: Rick Hofstede <r.j.hofstede@utwente.nl>
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Subject: Re: [IPFIX] Interpretation of sequence number handling
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hi Rick,

Yep, this is a good point. Could you file an editorial erratum?

Thanks, cheers,

Brian

> On 19 Jun 2015, at 10:37, Rick Hofstede <r.j.hofstede@utwente.nl> wrote:
> 
> Dear list,
> 
> RFC 7011 defines the following regarding sequence numbers in Message headers (Section 3.1 — Message Header Format): Incremental sequence counter modulo 2^32 of all IPFIX Data Records sent in the current stream from the current Observation Domain by the Exporting Process.
> 
> This can however be interpreted in two ways:
> 
> (1) Incremental sequence counter modulo 2^32 of all IPFIX Data Records sent in the current stream from the current Observation Domain by the Exporting Process *up to* this Message.
> (2) Incremental sequence counter modulo 2^32 of all IPFIX Data Records sent in the current stream from the current Observation Domain by the Exporting Process *up to and including* this Message.
> 
> It seems that only Section 10.3.2 — Reliability explains which of the two interpretations is right: In the case of UDP, the IPFIX Sequence Number contains the total number of IPFIX Data Records sent for the Transport Session *prior* to the receipt of this IPFIX Message, modulo 2^32.
> 
> In my opinion, it would be good to clarify the use of sequence numbers in Message headers already in the definition of sequence numbers in RFC 7011, namely in Section 3.1.
> 
> Best regards,
> 
> —
> Rick Hofstede
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