Joel,
> Thank you.  These changes sufficiently address my concerns.
>
> (I rather like the one case where the text reads "the tester must 
> check and if necessary improve the software so that ...".  Why do I 
> think that this is something folks have tripped over before? :-)
Oops. This was not supposed to be there. It was agreed to remove that 
part of the sentence before posting the draft ;-)

OLD:

   The tester must check and if necessary improve the software so that
   the Templates and the associated Data Records are correctly received
   and decoded by the Collecting Process.

NEW:
   The tester must check that
   the Templates and the associated Data Records are correctly received
   and decoded by the Collecting Process.


>
> I appreciate your efforts in addressing the issues.
You're welcome.

Regards, Benoit.
> Yours,
> Joel M. Halpern
>
> Benoit Claise wrote:
>>   Dear Joel,
>>
>> I posted a new version of the testing draft
>>
>>     A new version of I-D, draft-ietf-ipfix-testing-05.txt has been 
>> successfuly submitted by Benoit Claise and posted to the IETF 
>> repository.
>>
>>     Filename:     draft-ietf-ipfix-testing
>>     Revision:     05
>>     Title:         Guidelines for IP Flow Information eXport (IPFIX) 
>> Testing
>>     Creation_date:     2008-04-14
>>     WG ID:         ipfix
>>     Number_of_pages: 38
>>
>>     Abstract:
>>     This document presents a list of tests for implementers of IP Flow
>>     Information Export (IPFIX) compliant Exporting Processes and
>>     Collecting Processes.  This document specifies guidelines for a
>>     series of tests that can be run on the IPFIX Exporting Process and
>>     Collecting Process in order to probe the conformity and 
>> robustness of
>>     the IPFIX protocol implementations.  These tests cover all important
>>     functions, in order to gain a level of confidence in the IPFIX
>>     implementation.  Therefore they allow the implementer to perform
>>     interoperability or plug tests with other IPFIX Exporting Processes
>>     and Collecting Processes.Conventions used in this document
>>
>> We hope to have addressed your concerns successfully. Would you mind 
>> checking this latest version.
>> Note: we have addressed your point 10), as we thought we didn't want 
>> to be that formal in our test description.
>>
>> Regards, Benoit.
>>
>>
>>>  I have been selected as the General Area Review Team (Gen-ART)
>>> reviewer for this draft (for background on Gen-ART, please see
>>> http://www.alvestrand.no/ietf/gen/art/gen-art-FAQ.html ).
>>>
>>> Please resolve these comments along with any other Last Call comments
>>> you may receive.
>>>
>>> Document: Guidelines for IP Flow Information eXport (IPFIX) Testing
>>> Reviewer: Joel M. Halpern
>>> Review Date: 15-Feb-2008
>>> IETF LC End Date: 26-Feb-2008
>>> IESG Telechat date: N/A
>>>
>>> Summary: This document needs some additional work before publication 
>>> as an informational RFC.
>>> I would particularly recommend considering addressing at least the 
>>> first comment below prior to RFC publication.
>>> I would also suggest that the test descriptions need some 
>>> clarification as described in the technical section below, 
>>> particularly items 5 and 6.
>>>
>>> Comments:
>>>
>>> Conceptual:
>>> 1) While the document is being published as an information RFC, the 
>>> wording of the abstract and introduction make it seem that this 
>>> document is actually defining conformance to the IPFIX RFCs.  The 
>>> IETF has generally carefully steered clear of defining such 
>>> conformance.
>>> So, while publishing a useful test suite is probably a good idea, I 
>>> strongly recommend fixing the wording of at least the abstract and 
>>> introduction to make it quite clear that these are not mandatory 
>>> tests, and that these tests do not define conformance.
>>> Related to this, please do not assert (in section 3) that passing 
>>> this test suite constitutes conformance to the IPFIX architecture 
>>> and protocol.  (Among other things,test suite passage proves nothing 
>>> about architectural conformance.)
>>>
>>>
>>> Technical:
>>> 2) In the terminology section, an Observation Point is defined 
>>> simply as a place where packets can be observed.  An Observation 
>>> Domain is a collection of Observation points.  Then, in the middle 
>>> of the definition of an Observation domain it say "In the IPFIX 
>>> MEssage it generates..." but up till now none of the things that 
>>> have been defined generate IPFIX messages.  It is possible that the 
>>> "it" in the quote is supposed to be the "Metering Process" mentioned 
>>> in passing earlier in the definition. But the English grammar does 
>>> not lead the reader to such a conclusion. Later in that same 
>>> definition, it beings to appear that an Observation Domain (which is 
>>> a collection of points, not a process or entity) is supposed to 
>>> generate IPFIX messages, since it is supposed to include a Domain ID 
>>> in the messages it generates.  This definition for an Observation 
>>> Domain needs to be reworked, to avoid confusing the Domain with the 
>>> Measurement Process which is running in / for / on the Domain.
>>>
>>> 3) The use of capital "MUST" in section 3.1 is almost certainly 
>>> wrong. Firstly, what I think that section is saying is that being 
>>> able to correctly perform the basic tests is a precondition for 
>>> being able to perform further test successfully.  Thats a 
>>> precondition, not a "MUST".
>>> Of lesser significance, this document does not provide any 
>>> description of what it means by "MUST".  We are usually careful 
>>> about how such language is used in informational RFCs.  I think the 
>>> meaning would be clearer if the real intent were stated.  I suspect 
>>> that some readers of this review may find my concern here pedantic.  
>>> But the continual use of MUST in the document really, really bothers 
>>> me. (I hope the next comment helps explain why it bothers me so much.)
>>>
>>> 4) Then, the test descriptions go on to keep using this language.  
>>> This is a test suite description document.  Simply state how to run 
>>> the test.  There is no need for "MUST".  Section 3 should indicate 
>>> that the test descriptions describe the preconditions and steps that 
>>> the tester goes through.  So section 3.1 would begin "The tester 
>>> creates one Exporting Process and one collection process, configures 
>>> the Exporting Process to ..."
>>>
>>> 5) It is not clear what test steps like ~The tester ensures that an 
>>> SCTP association is established.~ (Or worse, the actual text which 
>>> reads "the test MUST ensure that an SCTP association is 
>>> established." are supposed to do.  Is this an instruction to the 
>>> tester to use network management tools or CLI to verify a connection 
>>> on both devices?  Is it an instruction to perform additional 
>>> configuration?  How does the tester "ensure".  A test suite should 
>>> tell a tester what steps to undertake, and what observations to 
>>> perform.  "Ensure" is not either one of those.
>>> 5a) To elaborate on this issue, in the middle of the test step about 
>>> ensuring that Data Records are actually exported, we finally get a 
>>> testable instruction, to whit, use a packet sniffer and check that 
>>> the packets are coming by.
>>>
>>> 6) I believe I understand how a tester would create templates, for 
>>> the template test.  But how is the tester to create data sets.  
>>> Particularly data sets with specific properties, such as the padding 
>>> in section 3.2.3 and 3.2.4?  The best conclusion I can come to is 
>>> that this is a collector test, and that it assumes a packet 
>>> generator which can generate IPFIX packets.  Having such a device in 
>>> a test setup makes sense.  But the test description does not say 
>>> "configure a packet generator to generate an IPFIX packet with ..."  
>>> (There are other ways to say this, but there needs to be some 
>>> description of how testers are expected to create data sets.)
>>> 6a) Related to this, I find reading this document rather odd.  I 
>>> have read many test suites for protocols and implementations of 
>>> protocols. They generally focus on a Device (or implementation, or 
>>> entity) Under Test, and the framing around that Device.  This suite 
>>> appears to be trying to test two interacting devices 
>>> simultaneously.  That is extremely difficult, and extremely 
>>> confusing.  It is particularly hard because then the tester doesn't 
>>> have enough points of control to perform the tests and observe the 
>>> results meaningfully.  It is possible that this combined suite is 
>>> right for this problem.  But if so, a lot of explanation of why it 
>>> is done that way and how the tester is to accomplish his goals is 
>>> needed.
>>>
>>> Minor:
>>> 7) The abstract is worded as if one could not perform 
>>> interoperability testing without first running the tests in this 
>>> document.  While having run the tests in this document will 
>>> presumably increase the chances of a successful interoperability 
>>> test, they are not an inherent requirement for such testing.
>>>
>>> 8) I would probably be inclined to lighten up the Motivation section 
>>> a bit.  Or even remove it.  I don't think we need to explain why 
>>> test suites are useful.  If we really need a motivation section, 
>>> then it should explain something about why it is particularly 
>>> complex to test IPFIX implementations (if it is) and thus why the 
>>> IETF feels it is particularly useful to publish a test suite 
>>> ourselves in this case.
>>>
>>> 9) The definition of Transport Session is actually the definition of 
>>> various kinds of transport sessions, and how they are identified.  
>>> Could the definition start with an actual definition please. (I.e. 
>>> the communication over time used to carry X between Y and Z?  Or 
>>> something.)
>>>
>>> 10) As an editorial matter, most testers I have worked with strongly 
>>> prefer if every step in a test is explicitly separate and named / 
>>> numbered.  That way, they can check off each step as it goes.  So 
>>> the beginning of 3.1.1 would be
>>> i) Create One Exporting Process
>>> ii) Create One Collection  Process
>>> iii) Configure the Exporting Process ...
>>>
>>> 11) It is particularly odd to see a set of Stress/Load tests that 
>>> simultaneously claim to be measuring conformance and to not specify 
>>> the level of Stress / Load.  Having a description of how to perform 
>>> load tests is useful.  But its relationship to the other tests is 
>>> confusing.  (This obviously is helped once we no longer claim that 
>>> this is a conformance test.)
>>>
>>>
>>

_______________________________________________
Gen-art mailing list
[email protected]
https://www.ietf.org/mailman/listinfo/gen-art

Reply via email to