Hi Mirja,

Friendly Reminder...Could you please also advice if there is anything
further to DISCUSS on this document which was also related to TCP updates
below?

Cheers,

Gaurav

On Thu, Jun 7, 2018 at 9:02 AM, Alvaro Retana <aretana.i...@gmail.com>
wrote:

> Thanks Martin!
>
> On June 6, 2018 at 3:14:45 PM, Martin Stiemerling (mls.i...@gmail.com)
> wrote:
>
> Hi Alvaro, all,
>
> Thanks for addressing my concerns.
>
> This version is good to go from my side.
>
> Kind regards,
>
> ;Martin
>
> Am 30.05.18 um 21:55 schrieb Alvaro Retana:
> > Martin:
> > br/>> Hi!!  How are you?
> > br/>> Gaurav just posted a revision.  Please takke a look and let us
> know if br/>> the changes address your concerrns or not.
> > br/>> https://www.ietf.org/rfcdiff??url2=draft-ietf-spring-
> segment-routing-msdc-09
> > br/>> Thanks!!!
> > br/>> Alvaro. <
> > br/>> On May 25, 2018 at 12:08:46 PM, Gaurav Dawra ((
> gdawra.i...@gmail.com br/>> <mailto:gdawra.ietf@@gmail.com>) wrote:
> > br/>>> Hi Martin, <
> >>
> >> Thanks for review. I will post the new version. Hopefully, it will
> br/>>> address all your comments and we can close thhis review.
> >>
> >> Any updates on below response?
> >>
> >> Cheers,
> >>
> >> Gaurav
> >>
> >> Sent from my iPhone
> >>
> >> On May 23, 2018, at 4:17 AM, Gaurav Dawra <gdawra.i...@gmail.com
> br/>>> <mailto:gdawra.ietf@@gmail.com>> wrote:
> >>
> >>> Hi Martin,
> >>>
> >>> Thanks for the review. Any further comments here ? I will post the
> br/>>>> new version soon. <
> >>>
> >>> Cheers,
> >>>
> >>> Gaurav
> >>>
> >>> Sent from my iPhone
> >>>
> >>> On May 16, 2018, at 7:44 PM, Gaurav Dawra <gdawra.i...@gmail.com
> br/>>>> <mailto:gdawra.ietf@@gmail.com>> wrote:
> >>>
> >>>> Hi Martin,
> >>>>
> >>>> Apologies from my end we had few internal authors conversations on
> br/>>>>> the points you have raised. <
> >>>>
> >>>> Please find below my response. I will be happy to discuss further,
> br/>>>>> if needed. <
> >>>>
> >>>> <Gaurav> inline...
> >>>>
> >>>>> On Apr 9, 2018, at 7:58 AM, Martin Stiemerling <mls.i...@gmail.com
> br/>>>>>> <mailto:mls.ii...@gmail.com>> wrote:
> >>>>>
> >>>>> Hi Gaurav,
> >>>>>
> >>>>> This got lost on my end, sorry for this. The filter just moved
> br/>>>>>> these messages out of my sight... :-/
> >>>>>
> >>>>> Am 15.02.18 um 05:47 schrieb Gaurav Dawra:
> >>>>>> Hey Martin,
> >>>>>> Sorry for late reply. Please see some comments inline[Gaurav]
> >>>>>>> On Jan 9, 2018, at 2:25 PM, Martin Stiemerling br/>>>>>>>>
> <mls.ietf@@gmail.com <mailto:mls.i...@gmail.com> br/>>>>>>>>; <mailto:
> mls.i...@gmail.com>> wrote:
> >>>>>>>
> >>>>>>> Hi all,
> >>>>>>>
> >>>>>>> I've reviewed this document as part of the transport area review
> br/>>>>>>>> team's ongoing effort to review key IETF documents. These
> br/>>>&gtt;>>>> comments were written primarily for the transport area
> directors, br/>>>>>>>> but are copied to the doocument's authors for their
> information br/>>>>>>>&> and to allow them to address any issues raised.
> When done at the
> >>>>>>> time of IETF Last Call, the authors should consider this review
> br/>>>>>>>> together with any other last-call comments they receive. Please
> br/>>>&>>>>> always CC tsv-art@… if you reply to or forward this review.
> >>>>>>>
> >>>>>>> Summary:
> >>>>>>> This draft has serious issues in Section 7.1, 7.2 and in one part
> br/>>>>>>>> of Secction3, described in the review, and needs to be
> rethought. br/>>&>>>>>> The other sections are good AFAIK.
> >>>>>>>
> >>>>>>>
> >>>>>>> Technicals:
> >>>>>>> The overall draft looks ok, but the three points below look
> br/>>>>>>>> strange and need a fix before publication IMHO:
> >>>>>>>
> >>>>>>> Both Sections, 7.1. and 7.2., are describing ideas, but not well
> br/>>>>>>>> proven funcationality and not even safe to use functionality.
> br/>>>&>>>>> Both are some sort discussing that different paths in the
> network br/>>>>>>>> could be used by the eend host traffic. This sounds
> pretty much br/>>>>>>&gtt;> like the Path Aware Networking Proposed
> Research Group br/>&gtt;>>>>>> (https://irtf.org/panrg) and hints to the
> fact that there is no br/>>>>>>>> commonly understannd and accepted
> engineering solution in this space.
> >>>>>>>
> >>>>>>> Section 7.1:
> >>>>>>> [KANDULA04] is a really old reference that hasn't been followed
> br/>>>>>>>> up iin recent times and even worse there is no evidence that
> this br/>&gtt;>>>>>> is going to work good enough or stable enough under
> real Internet br/>>>>>>>> traffic. Additioonally, it is more than unclear
> how any modern TCP br/>>>>&ggt;>>> implementation will react to this
> >>>>>> [Gaurav] Will get back on this.
> >>>>>
> >>>>> I will reply to the other email dicussing this.
> >>>> <Gaurav> I have replied to other thread.
> >>>>>
> >>>>>>>
> >>>>>>> Section 7.2:
> >>>>>>> This section describes an idea without detailing too much about
> br/>>>>>>>> any furtther aspects. Further it changes the commonly accepted
> br/>>>;>>>>> notion of what an end host can do with the network. At best
> this br/>>>>>>>> would require a good ddefinition of what an end host in
> your br/>>>>>>>&ggt; setting is, e.g., a highly modified piece of (at
> least) software
> >>>>>>> that usually not found in OS availble on the market (yet?)
> >>>>>>> Further communicating instantaneous path characteristics to a
> br/>>>>>>>> central point is potentially a bad idea, as the data is already
> br/>>>;>>>>> outdated when reported by any node.
> >>>>>> [Gaurav] I believe Authors are trying to highlight that Host which
> br/>>>>>>> is defineed in br/>>>>>>> (https://tools.ietf.org/html/
> draftt-ietf-spring-segment-routing-15) br/>>>>>>> can innfluence the
> traffic based on the Calculations locally or br/>>&gtt;>>>> jointly with
> the controller. Implementations can decide how much br/>>>>>>> Centralized
> -vs- localized coontrol is allowed at Host based on br/>>>>>>> perfoormance
> data collection.
> >>>>>
> >>>>> Performance data collection (monitoring?) isn't crucial when it
> br/>>>>>> comes to timely (actuaally real-time) reaction. However, this
> br/>>>>>> secttion isn't just about performance data collection as it is
> about br/>>>>>>> "Performance-aware routing" this seems to try to interact
> in br/>>>>>> real-time with the network behhavior of TCP. This isn't even
> close br/>>>>>> to acceeptable.
> >>>>>
> >>>>> I would be ok to say that it is useful to collect performance data
> br/>>>>>> for offline analysis and improvement of the data network.
> However, br/>>>>>&ggt; this is at completely different magnitues of time
> scales.
> >>>>>
> >>>>> I would recommend to remove the TCP part from this section entirely..
> >>>> <Gaurav>Ack, will update in next rev:
> >>>>
> >>>> Section will read like this:
> >>>>
> >>>> ;
> >>>> /Knowing the path associated with flows/packets, the end host may/
> >>>> /deduce certain characteristics of the path on its own, and/
> >>>> /additionally use the information supplied with path information/
> >>>> /pushed from the controller or received via pull request. The host/
> >>>> /may further share its path observations with the centralized agent,/
> >>>> /so that the latter may keep up-to-date network health map to assist/
> >>>> /other hosts with this information./
> >>>> //
> >>>> /For example, an application A.1 at HostA may pin a flow destined/
> >>>> /to HostZ via Spine node Node5 using label stack {16005, 16011}. The/
> >>>> /application A.1 may collect information on packet loss, deduced
> from/
> >>>> /Other offline mechanisms. [There are some pingMesh mechanisms which
> /
> >>>> /Can be used here]/
> >>>> /Through these mechanisms information to a centralized agent, e.g./
> >>>> /after a flow completes, or periodically for longer lived flows./
> >>>> /Next, using both local and/or global performance data, application/
> >>>> /A.1 as well as other applications sharing the same resources in the/
> >>>> /DC fabric may pick up the best path for the new flow, or update an/
> >>>> /existing path (e.g.: when informed of congestion on an existing/
> >>>> /path)./
> >>>> ;
> >>>>
> >>>>>
> >>>>>
> >>>>>>>
> >>>>>>> Section 3, 3rd bullet point:
> >>>>>>> It is the foundation of TCP that the network is regarded as a
> br/>>>>>>>> black box and that you infer from the transmission of packets
> br/>>>>;>>>> what the current state of the network path is. Inferring
> network br/>>>>>>>> path metrics (you mention SRTT, MSS, CWND ) is a bad
> idea, as br/>>>>>>>>; this would required that all paths exhibit this and
> if not what br//>>>>>>>> is going to happen?
> >>>>>>> It could be an interesting research field to change many points
> br/>>>>>>>> in TCP'ss behavior, but this once again points to the fact that
> br/>>>&>>>>> this not the IETF works but IRTF or elsewhere.
> >>>>>> [Gaurav] Martin, Authors are trying to suggest that TCP is rightly
> br/>>>>>>> treating Network as Black Box. Authors are implying per path
> br/>>>>;>>> performance metrics as not cached. Is there some change in text
> br/>>>>>>> you are suggesting??
> >>>>>
> >>>>>
> >>>>> I would recommend to remove the 3rd bullet point completey. TCP
> br/>>>>>> isn't the place to rememmber "good" or "bad" paths. This is
> br/>>>>>> something the network could decide, e.g., rerouting TCP flows
> br/>&ggt;>>>> within the network or changing the forwarding path in the
> network br/>>>>>> for particular flows (if it is not routed).
> >>>>
> >>>> <Gaurav> Ack, after discussion, we will remove the Section 3 - 3rd
> br/>>>>> bullet point. Willl update in next rev - coming shortly.
> >>>>
> >>>>>
> >>>>> Kind regards,
> >>>>>
> >>>>>  Martin
> >>>>>
> >>>>
>
>
_______________________________________________
spring mailing list
spring@ietf.org
https://www.ietf.org/mailman/listinfo/spring

Reply via email to