Re: [IPFIX] New AD review of draft-ietf-ipfix-flow-selection-tech-10.txt
Benoit Claise <[email protected]>
| Newsgroups | gmane.ietf.ipfix |
|---|---|
| Message-ID | <[email protected]> |
Dear draft-ietf-ipfix-flow-selection-tech authors, I was expecting a quick discussion on the very few remaining issues... That has not happened. The draft status is: AD evaluation, Revised ID Needed. Regards, Benoit > Dear authors, > > The draft improved quite dramatically. > Thanks for that. > See in line for some more comments. I removed all unnecessary text. > >> Dear authors, >> >> I'm performing the (new) AD review of >> draft-ietf-ipfix-flow-selection-tech-10.txt >> Lucky you, an extra pair of eyes specifically looking at your draft >> >> If some points have been discussed already on the mailing list, let >> me know. I have to admit that I have not been following the latest >> iterations of this draft. >> >> IMHO, this document needs some more work... >> I don't think that this document is really in line with the other >> Intermediate Processes documents: >> http://tools.ietf.org/html/rfc6235 >> http://tools.ietf.org/html/draft-ietf-ipfix-a9n-03 >> Note that I might have some more comments once all the points in this >> email are addressed, as there are many ;-) >> However, I'm available for a conf. call to clarify my points if you >> want to >> >> See in-line. > ... >>> 8.2. Registration of Object Identifier . . . . . . . . . . . >>> . 32 >>> 9. Security Considerations . . . . . . . . . . . . . . . . . . >>> . 32 >>> 10. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . >>> . 34 >>> 11. References . . . . . . . . . . . . . . . . . . . . . . . . . >>> . 34 >>> 11.1. Normative References . . . . . . . . . . . . . . . . . . >>> . 34 >>> 11.2. Informative References . . . . . . . . . . . . . . . . . >>> . 34 >>> Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . >>> . 35 >> Don't you have to include the non-normative XML in the appendix, as >> it was done for RFC5102, RFC5103? >>> >> >>> 2. Terminology >>> >>> This document is consistent with the terminology introduced in >>> [RFC5101], [RFC5470], [RFC5475] and [RFC3917]. As in [RFC5101] and >>> [RFC5476], the first letter of each IPFIX-specific and >>> PSAMP-specific >>> term is capitalized along with the flow selection specific terms >>> defined here. >>> >>> * Packet Classification >>> >>> Packet Classification is a process by which packets are mapped to >>> specific Flow Records based on packet properties or external >>> properties (e.g. interface). The properties (e.g. header >>> information, packet content, AS number) make up the Flow Key. In >>> case a Flow Record for a specific Flow Key already exists the >>> Flow >>> Record is updated, otherwise a new Flow Record is created. >> >> How is this different that the Metering Process (RFC5101)? >> Metering Process >> >> The Metering Process generates Flow Records. Inputs to the >> process are packet headers and characteristics observed at an >> Observation Point, and packet treatment at the Observation Point >> (for example, the selected output interface). >> >> The Metering Process consists of a set of functions that includes >> packet header capturing, timestamping, sampling, classifying, and >> maintaining Flow Records. >> >> The maintenance of Flow Records may include creating new records, >> updating existing ones, computing Flow statistics, deriving >> further Flow properties, detecting Flow expiration, passing Flow >> Records to the Exporting Process, and deleting Flow Records. >> What is the connection with the Metering Process? >> Figure 1 seems to suggest that Packet Classification is a subset of >> the Metering Process... > not sure that one was answered. > >> >> >>> >>> * Packet Aggregation Process >>> >>> In the IPFIX Metering Process the Packet Aggregation Process >>> aggregates packet data into flow data and forms the Flow Records. >> How is this different from the Metering Process? > the "Packet Aggregation Process" is not used in the document. Why do > we need it? > >>> After the aggregation step only the aggregated flow information is >>> available. Information about individual packets is lost. >>> >>> >>> >> Intermediate Flow Selection Process: an Intermediate Process as in >> [RFC6183 <http://tools.ietf.org/html/rfc6183>] that ... >> >> > The new definition improved a lot: > * Intermediate Flow Selection Process > > An Intermediate Flow Selection Process takes Flow Records as its > input and selects a subset of this set as its output. > Intermediate Flow Selection Process is a more general concept than > Intermediate Selection Process as defined in [RFC6183 <http://tools.ietf.org/html/rfc6183>]. While an > Intermediate Selection Process selects Flow Records from a > sequence based upon criteria-evaluated Flow record values and > passes only those Flow Records that match the criteria, an > Intermediate Flow Selection Process selects Flow Records using > selection criteria applicable to a larger set of Flow > characteristics and information. > But is there a reason why this definition can't be based on > "intermediate Process" from RFC 6183: > > Intermediate Process > > An Intermediate Process takes a record stream as its input from > Collecting Processes, Metering Processes, IPFIX File Readers, > other Intermediate Processes, or other record sources; performs > some transformations on this stream based upon the content of each > record, states maintained across multiple records, or other data > sources; and passes the transformed record stream as its output to > Exporting Processes, IPFIX File Writers, or other Intermediate > Processes in order to perform IPFIX Mediation. Typically, an > Intermediate Process is hosted by an IPFIX Mediator. > Alternatively, an Intermediate Process may be hosted by an > Original Exporter. > > So > > * Intermediate Flow Selection Process > > _ An Intermediate Flow Selection Process is__an Intermediate Process as in > [_RFC6183 <http://tools.ietf.org/html/rfc6183>_] that_ takes Flow Records as its > input and selects a subset of this set as its output. > Intermediate Flow Selection Process is a more general concept than > Intermediate Selection Process as defined in [RFC6183 <http://tools.ietf.org/html/rfc6183>]. While an > Intermediate Selection Process selects Flow Records from a > sequence based upon criteria-evaluated Flow record values and > passes only those Flow Records that match the criteria, an > Intermediate Flow Selection Process selects Flow Records using > selection criteria applicable to a larger set of Flow > characteristics and information. > >>> > > Regarding terminology, I still some instances of "observation point". > Should be "Observation Point" > > ... > >>> >>> 4. Flow selection as a Function in the IPFIX Architecture >>> > Thanks for your new figure 1. > One editorial change: change the + in the left vertical line. > > +======|========================+ | > | | Mediator | | > + +-V-------------------+ | | > | | Collecting Process | | | > + +---------------------+ | | > | | Intermediate Flow | | | > | | Selection Process | | | > + +---------------------+ | | > | | Exporting Process | | | > + +-|-------------------+ | | > +======|========================+ | > >>> >>> 5.1. Flow Filtering >>> >>> Flow Filtering is a deterministic function on the IPFIX Flow Record >>> content. If the relevant flow characteristics are already >>> observable >>> at packet level (e.g. Flow Keys), Flow Filtering can be applied >>> before aggregation at packet level. In order to be compliant with >>> this document, at least the Property Match Filtering MUST be >>> implemented. >> This contradicts. >> In order to be compliant with this document, at >> least one of the flow selection schemes MUST be implemented. > Actually, wrong cut/paste. > This contradicts, in section 1: > In order to be compliant with this document, at > least the Property Match Filtering MUST be implemented. > > >>> >>> 8. IANA Considerations >>> >>> 8.1. Registration of Information Elements > > Table 3: Information Elements to be registered, you can't put the > value 1, 2, 3, > You need TBD1, TBD2, etc... > And you must add > "IANA Note: please replace TBD1, TBD2, ... with the assigned values, > throughout the document." > >>> >>> >>> 8.2. Registration of Object Identifier >>> > > RFC 5815 is obsoleted by RFC 6615 <http://tools.ietf.org/html/rfc6615> > > What you want is an extra in > http://www.iana.org/assignments/smi-numbers, pointing to this RFC: > > Sub-registry Name: IPFIX-SELECTOR-MIB Functions > Reference: [RFC6615] > Registration Procedures: Expert Review > Prefix: iso.org.dod.internet.mgmt.mib-2.ipfixSelectorMIB.ipfixSelectorObjects.ipfixSelectorFunctions > (1.3.6.1.2.1.194.1.1) > > Decimal Name Description Reference > ------- --------------------- --------------------------------- --------- > 1 ipfixFuncSelectAll Select everything [RFC6615] > 2 psampSampCountBased Systematic Count-based Sampling [RFC6727] > 3 psampSampTimeBased Systematic Time-based Sampling [RFC6727] > 4 psampSampRandOutOfN Random n-out-of-N Sampling [RFC6727] > 5 psampSampUniProb Universal Probabilistic Sampling [RFC6727] > 6 psampFiltPropMatch Property Match Filtering [RFC6727] > 7 psampFiltHash Hash-based Filtering [RFC6727] > > So you need TBDx > > +---------+-----------------------+---------------------+-----------+ > | Decimal | Name | Description | Reference | > +---------+-----------------------+---------------------+-----------+ > | TBDx | flowSelectorAlgorithm | This Object | [RFCyyyy] | > | | | Identifier | | > | | | identifies the Flow | | > | | | selection technique | | > | | | (e.g., Filtering, | | > | | | Sampling) that is | | > | | | applied by the Flow | | > | | | Selection Process | | > +---------+-----------------------+---------------------+-----------+ > > Table 4: Object Identifiers to be registered > > "IANA Note: please replace TBDx with the assigned value, throughout > the document." > > Btw, there is a mismatch between the IANA registry and the table in > section 7.1: > +----+------------------------+--------------------------+ > | ID | Technique | Parameters | > +----+------------------------+--------------------------+ > | 1 | Systematic count-based | flowSamplingInterval | > | | Sampling | flowSamplingSpacing | > +----+------------------------+--------------------------+ > | 2 | Systematic time-based | flowSamplingTimeInterval | > | | Sampling | flowSamplingTimeSpacing | > +----+------------------------+--------------------------+ > | 3 | Random n-out-of-N | samplingSize | > | | Sampling | samplingPopulation | > +----+------------------------+--------------------------+ > | 4 | Uniform probabilistic | samplingProbability | > | | Sampling | | > +----+------------------------+--------------------------+ > | 5 | Property Match | Information Element | > | | Filtering | Value Range | > +----+------------------------+--------------------------+ > | Hash-based Filtering | hashInitialiserValue | > +----+------------------------+ hashFlowDomain | > | 6 | using BOB | hashSelectedRangeMin | > +----+------------------------+ hashSelectedRangeMax | > | 7 | using IPSX | hashOutputRangeMin | > +----+------------------------+ hashOutputRangeMax | > | 8 | using CRC | | > +----+------------------------+--------------------------+ > | 9 | Flow-state Dependent | No agreed Parameters | > | | Flow Selection | | > +----+------------------------+--------------------------+ > > Also, in this table above, you need "TBDx" instead of 9 > - I see "Flow Selection", but this term is not defined. > > Thanks. > > > Regards, Benoit. > > > _______________________________________________ > IPFIX mailing list > [email protected] > https://www.ietf.org/mailman/listinfo/ipfix _______________________________________________ IPFIX mailing list [email protected] https://www.ietf.org/mailman/listinfo/ipfix