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@xxxxxxx> 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@xxxxxxxxxxxx] >> Sent: Thursday, August 22, 2013 3:06 PM >> To: Black, David >> Cc: ben@xxxxxxxxxxx; General Area Review Team (gen-art@xxxxxxxx); >> ietf@xxxxxxxx; dime@xxxxxxxx; bclaise@xxxxxxxxx >> 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@xxxxxxx> 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@xxxxxxx Mobile: +1 (978) 394-7754 >>> ---------------------------------------------------- >>> >> >