Telechat Review of draft-ietf-dime-overload-reqs-12
review-ietf-dime-overload-reqs-12-genart-telechat-black-2013-09-20-00

Request Review of draft-ietf-dime-overload-reqs
Requested rev. no specific revision (document currently at 13)
Type Telechat Review
Team General Area Review Team (Gen-ART) (genart)
Deadline 2013-09-24
Requested 2013-09-04
Other Reviews Genart Last Call review of -10 by David Black (diff)
Secdir Last Call review of -10 by Carl Wallace (diff)
Review State Completed
Reviewer David Black
Review review-ietf-dime-overload-reqs-12-genart-telechat-black-2013-09-20
Posted at http://www.ietf.org/mail-archive/web/gen-art/current/msg09041.html
Reviewed rev. 12 (document currently at 13)
Review result Ready
Draft last updated 2013-09-20
Review completed: 2013-09-20

Review
review-ietf-dime-overload-reqs-12-genart-telechat-black-2013-09-20

And the -12 version is likewise ready for publication as an Informational RFC.

Thanks,
--David

> -----Original Message-----
> From: Black, David
> Sent: Tuesday, August 27, 2013 12:41 PM
> To: Ben Campbell
> Cc: Eric McMurry; General Area Review Team (gen-art at ietf.org); ietf at ietf.org;
> dime at ietf.org; bclaise at cisco.com; Black, David
> Subject: Gen-ART review of draft-ietf-dime-overload-reqs-11
> 
> The -11 version of this draft addresses all of the nits and editorial comments
> noted in the Gen-ART review of the -10 version.  It's ready for publication as
> an Informational RFC.
> 
> Thanks,
> --David
> 
> > -----Original Message-----
> > From: Ben Campbell [

mailto:ben

 at nostrum.com]
> > Sent: Thursday, August 22, 2013 4:50 PM
> > To: Black, David
> > Cc: Eric McMurry; General Area Review Team (gen-art at ietf.org);
> ietf at ietf.org;
> > dime at ietf.org; bclaise at cisco.com
> > Subject: Re: Gen-ART review of draft-ietf-dime-overload-reqs-10
> >
> > Hi David,
> >
> > We agree on all your points, and will make the updates in the next version,
> > pending shepherd instructions.
> >
> > Thanks!
> >
> > Ben.
> >
> > On Aug 22, 2013, at 2:50 PM, "Black, David" <david.black at emc.com> wrote:
> >
> > > Hi Eric,
> > >
> > > This looks good - comments follow ...
> > >
> > >>> a) I assume that overload control development work will derive more
> > specific
> > >>> security requirements - e.g., as REQ 27 is stated at a rather high
> level.
> > >>> The discussion in security considerations section seems reasonable.
> > >>
> > >> We agree with this.  The thinking here was that we didn't want to specify
> this
> > >> in a way that would be specific to a particular type of mechanism.  It
> might
> > >> not hurt to state that assumption, either as a note on Req 27 or in the
> sec
> > >> considerations.
> > >
> > > That would be good to add as a note on REQ 27.
> > >
> > >> The intent was very much as you say, where requirements on individual
> node
> > >> capabilities are hoped to result in better overall system behaviors.
> There are
> > >> also some requirements that are stated more at the system level (e.g. 7
> and
> > >> 17.) Also the text in section 2.2 that discusses Figure 5 talks about how
> > >> insufficient server capacity at a cluster of servers behind a Diameter
> agent
> > >> can be treated as if the agent itself was overloaded.
> > >>
> > >> On the other hand, any mechanism we design will have to focus on actions
> of
> > >> individual nodes, so the numbered requirements tend to focus on that. I'm
> not
> > >> sure where to change the balance here--do you have specific suggestions?
> > >
> > > I noted this as editorial rather than a minor issue, as I was mostly
> concerned
> > > that the actual design work will be informed by a sufficient architectural
> "clue"
> > > that the goal is "better overall system behaviors", which your response
> indicates
> > > will definitely be the case ;-).
> > >
> > > Rather than edit individual requirements, how about adding the following
> sentence
> > > immediately following the introductory sentence in Section 7?:
> > >
> > > 	These requirements are stated primarily in terms of individual node
> > > 	behavior to inform the design of the improved mechanism;
> > > 	that design effort should keep in mind that the overall goal is
> > > 	improved overall system behavior across all the nodes involved,
> > > 	not just improved behavior from specific individual nodes.
> > >
> > >>> This inadequacy may, in turn, contribute to broader congestion collapse
> > >>>
> > >>> "collapse" is not the right word here - I suggest "issues", "impacts",
> > >>> "effects" or "problems".
> > >>
> > >> We are fine with any of those alternatives.  How about impacts.
> > >
> > > That's fine.  FWIW, "congestion collapse" has a specific (rather severe)
> > > meaning over in the Transport Area, and that meaning was not intended
> here.
> > >
> > >> 23.843 is the least stable reference.  I don't have any issue with
> pointing
> > >> that out.  The part of it we are referencing is historical front matter
> > >> though.
> > >
> > > I'd note the reference as work in progress, and put the statement about
> stable
> > > front matter (historical is a bad work to use here) in the body of the
> draft
> > > that cites the reference.
> > >
> > >> I tried the web and downloaded versions of 2.12.17 and was not able to
> get the
> > >> warnings you saw (about the references).  What did it say?
> > >
> > > Sorry, I didn't mean to send you on a wild goose chase :-).  The idnits
> confusion
> > > manifested right at the top of the output, where everyone ignores it ...
> > >
> > >   Attempted to download rfc272 state...
> > >   Failure fetching the file, proceeding without it.
> > >
> > > You didn't reference RFC 272, so that output's apparently courtesy of
> idnits
> > > misinterpreting this reference:
> > >
> > > 1195	   [TS29.272]
> > > 1196	              3GPP, "Evolved Packet System (EPS); Mobility
> Management
> > > 1197	              Entity (MME) and Serving GPRS Support Node (SGSN)
> related
> > > 1198	              interfaces based on Diameter protocol", TS 29.272
> 11.4.0,
> > > 1199	              September 2012.
> > >
> > > I was amused :-).
> > >
> > > Thanks,
> > > --David
> > >
> > >> -----Original Message-----
> > >> From: Eric McMurry [

mailto:emcmurry

 at computer.org]
> > >> Sent: Thursday, August 22, 2013 3:06 PM
> > >> To: Black, David
> > >> Cc: ben at nostrum.com; General Area Review Team (gen-art at ietf.org);
> > >> ietf at ietf.org; dime at ietf.org; bclaise at cisco.com
> > >> Subject: Re: Gen-ART review of draft-ietf-dime-overload-reqs-10
> > >>
> > >> Hi David,
> > >>
> > >> Thank you for the review.  Your time and comments are appreciated!
> > >>
> > >> comments/questions inline.
> > >>
> > >>
> > >> Eric
> > >>
> > >>
> > >>
> > >> On Aug 17, 2013, at 9:18 , "Black, David" <david.black at emc.com> wrote:
> > >>
> > >>>
> > >>> I am the assigned Gen-ART reviewer for this draft. For background on
> > >>> Gen-ART, please see the FAQ at
> > >>>
> > >>> <

http://wiki.tools.ietf.org/area/gen/trac/wiki/GenArtfaq>.
> > >>>
> > >>> Please resolve these comments along with any other Last Call comments
> > >>> you may receive.
> > >>>
> > >>> Document: draft-ietf-dime-overload-reqs-10
> > >>> Reviewer: David L. Black
> > >>> Review Date: August 17, 2013
> > >>> IETF LC End Date: August 16, 2013
> > >>> IESG Telechat date: (if known)
> > >>>
> > >>> Summary:
> > >>> This draft is basically ready for publication, but has nits that should
> be
> > >>> fixed before publication.
> > >>>
> > >>> This draft describes scenarios in which Diameter overload can occur and
> > provides
> > >>> requirements for development of new overload control functionality in
> > Diameter.
> > >>> It is well written, and the inclusion of scenarios in which overload can
> > occur,
> > >>> both in terms of the relationships among types of Diameter nodes and
> > actual mobile
> > >>> network experience is very helpful.
> > >>>
> > >>> I apologize for this review being a day late, as I've been on vacation
> for
> > most
> > >>> of this draft's IETF Last Call period.
> > >>>
> > >>> Major issues: (none)
> > >>>
> > >>> Minor issues: (none)
> > >>>
> > >>> Nits/editorial comments:
> > >>>
> > >>> The following two comments could be minor issues, but I'm going to treat
> > them
> > >>> as editorial, as I expect that they will be addressed in development of
> > the
> > >>> actual overload functionality:
> > >>>
> > >>> a) I assume that overload control development work will derive more
> > specific
> > >>> security requirements - e.g., as REQ 27 is stated at a rather high
> level.
> > >>> The discussion in security considerations section seems reasonable.
> > >>
> > >> We agree with this.  The thinking here was that we didn't want to specify
> > this
> > >> in a way that would be specific to a particular type of mechanism.  It
> > might
> > >> not hurt to state that assumption, either as a note on Req 27 or in the
> sec
> > >> considerations.
> > >>
> > >>>
> > >>> b) The draft, and especially its requirements in Section 7 are strongly
> > >>> focused on individual Diameter node overload.  That's necessary, but
> > overload
> > >>> conditions can be broader, affecting an entire service or application,
> or
> > >>> multiple instances of either/both, even if not every individual Diameter
> > node
> > >>> involved is overloaded.  A number of the requirements, starting with REQ
> > 22
> > >>> could be generalized to cover broader overload conditions.
> > >>>
> > >>> This (b) has implications for other requirements, e.g., REQ 13 should
> also
> > be
> > >>> generalized beyond a single node to avoid increased traffic in an
> overload
> > >>> situation, even from a node that is not overloaded by itself.  There are
> > limits
> > >>> on what is reasonable here, as the desired overload functionality is
> > TCP/SCTP-
> > >>> like reaction to congestion where individual actions taken by nodes
> based
> > on
> > >>> the information they have (which is not the complete state of the
> network)
> > >>> results in an overall reduction of load.
> > >>
> > >> The intent was very much as you say, where requirements on individual
> node
> > >> capabilities are hoped to result in better overall system behaviors.
> There
> > are
> > >> also some requirements that are stated more at the system level (e.g. 7
> and
> > >> 17.) Also the text in section 2.2 that discusses Figure 5 talks about how
> > >> insufficient server capacity at a cluster of servers behind a Diameter
> > agent
> > >> can be treated as if the agent itself was overloaded.
> > >>
> > >> On the other hand, any mechanism we design will have to focus on actions
> of
> > >> individual nodes, so the numbered requirements tend to focus on that. I'm
> > not
> > >> sure where to change the balance here--do you have specific suggestions?
> > >>
> > >>>
> > >>> Section 1.2, 2nd paragraph:
> > >>>
> > >>>  as network congestion, network congestion can reduce a Diameter nodes
> > >>>
> > >>> "nodes" -> "node's"
> > >>
> > >> good catch.
> > >>
> > >>>
> > >>> Section 5, 1st paragraph:
> > >>>
> > >>> This inadequacy may, in turn, contribute to broader congestion collapse
> > >>>
> > >>> "collapse" is not the right word here - I suggest "issues", "impacts",
> > >>> "effects" or "problems".
> > >>
> > >> We are fine with any of those alternatives.  How about impacts.
> > >>
> > >>>
> > >>> Section 7
> > >>>
> > >>> The long enumerated list of requirements is not an easy read.  It would
> be
> > >>> better if these could somehow be grouped by functional category, e.g.,
> > >>> security, transport interactions, operational/administrative, etc.
> > >>
> > >> agree.  It is actually in sections in the XML (denoted by comments), we
> > just
> > >> did not promote those to visible sections in the txt.  I recall there
> being
> > >> some issue with xml2rfc and numbering, but now that the numbers are set,
> > this
> > >> would not be hard to do.
> > >>
> > >>
> > >>>
> > >>> idnits 2.12.17 noticed the non-standard RFC 2119 boilerplate - this is
> > fine,
> > >>> as the boilerplate has been appropriately modified for this draft that
> > >>> expresses requirements (as opposed to a draft that specifies a
> protocol).
> > >>>
> > >>> idnits 2.12.17 got confused by the 3GPP and GSMA Informative References.
> > >>> I assume that they're all sufficiently stable to be informative
> > references.
> > >>> However, [TR23.843] is a work in progress, and should be noted as such
> in
> > >>> its reference - is this needed for any of the other 3GPP or GSMA
> > references?
> > >>
> > >> 23.843 is the least stable reference.  I don't have any issue with
> pointing
> > >> that out.  The part of it we are referencing is historical front matter
> > >> though.
> > >>
> > >>
> > >> I tried the web and downloaded versions of 2.12.17 and was not able to
> get
> > the
> > >> warnings you saw (about the references).  What did it say?
> > >>
> > >>
> > >>>
> > >>> Thanks,
> > >>> --David
> > >>> ----------------------------------------------------
> > >>> David L. Black, Distinguished Engineer
> > >>> EMC Corporation, 176 South St., Hopkinton, MA  01748
> > >>> +1 (508) 293-7953             FAX: +1 (508) 293-7786
> > >>> david.black at emc.com        Mobile: +1 (978) 394-7754
> > >>> ----------------------------------------------------
> > >>>
> > >>
> > >
> >