Re: [IPFIX] sectionOffset and sectionObservedOctets
Paul Aitken <[email protected]>
| Newsgroups | gmane.ietf.ipfix |
|---|---|
| Message-ID | <[email protected]> |
Brian, > Hi, Paul, all, > > To start the discussion: > > Actually, these make so much sense that I had to check the registry to make sure they weren't already there, and was surprised to find they're not. :-) > As for the sectionObservedOctets, it would be nice if it was made clearer that the observed octets reported is regardless of the offset... Great point, will do. > I'd be in favor of option 1 -- I think the changes to ipHeaderPacketSection can be made backward-compatible. Great. I'll propose some example text in one of my slides. Thanks, P. > On Aug 1, 2012, at 5:19 AM, Paul Aitken wrote: > >> Dear IPFIX experts, >> >> draft-ietf-ipfix-data-link-layer-monitoring-00 defines two new Information Elements: >> >> sectionOffset >> >> This Information Element specifies the offset of the packet >> section (e.g., dataLinkFrameSection, ipHeaderPacketSection, >> ipPayloadPacketSection, mplsLabelStackSection and >> mplsPayloadPacketSection). If this Information Element is >> omitted, it defaults to zero. >> >> >> sectionObservedOctets >> >> This Information Element specifies the observed length of the >> packet section (e.g., dataLinkFrameSection, ipHeaderPacketSection, >> ipPayloadPacketSection, mplsLabelStackSection and >> mplsPayloadPacketSection) when padding is used. >> >> The packet section may be of a fixed size larger than the >> sectionObservedOctets. In this case, octets in the packet section >> beyond the sectionObservedOctets MUST follow the [RFC5101] rules >> for padding (ie, be composed of zero (0) valued octets). >> >> >> These are intended for use in conjunction with the new "dataLinkFrameSection" Information Element: >> >> dataLinkFrameSection >> >> This Information Element carries n octets from the data link frame >> of a selected frame, starting sectionOffset octets into the frame. >> >> The sectionObservedOctets expresses how much data was observed, >> while the remainder is padding. >> >> >> Clearly sectionOffset and sectionObservedOctets can apply to all kinds of packet section, not just dataLinkFrameSection. >> >> ie, ipHeaderPacketSection, ipPayloadPacketSection, mplsLabelStackSection, mplsPayloadPacketSection. >> >> >> So I'm looking for WG feedback on the best way forward: >> >> 1: modify the existing packet section Information Elements Descriptions (in a backwards compatible way) to include sectionOffset and sectionObservedOctets. >> >> 2: deprecate the existing packet section Information Elements and create new Information Elements which include sectionOffset and sectionObservedOctets. >> >> 3: sectionOffset and sectionObservedOctets don’t apply to existing packet section Information Elements. >> >> >> I'll raise this issue while discussing the draft in the WG meeting >> >> Thanks, >> P. >> _______________________________________________ >> IPFIX mailing list >> [email protected] >> https://www.ietf.org/mailman/listinfo/ipfix _______________________________________________ IPFIX mailing list [email protected] https://www.ietf.org/mailman/listinfo/ipfix