Re: [Detnet] Transport sub-layer name change (Was Re: Tsvart last call review of draft-ietf-detnet-architecture-08)

["Andrew G. Malis" <[e-mail]>]

Lou,

I think we've discussed this before, but I wanted to confirm whether SRv6
is in scope for the DetNet Forwarding sub-layer.

Thanks,
Andy


On Thu, Dec 13, 2018 at 12:47 PM Lou Berger <[e-mail]> wrote:

> Hi,
>
>      My reading is that the WG has settled on:
>
>        +----------------------------+
>        |  DetNet Service sub-layer  | PW, UDP, GRE
>        +----------------------------+
>        | DetNet Forwarding sub-layer| IPv6, IPv4, MPLS TE LSPs, MPLS SR
>        +----------------------------+
>                      .
>                      .
>
>                    Figure 4: DetNet adaptation to data plane
>
> Authors, (of detnet-architecture)
>      Please work to have the next rev of the draft reflect this change.
>
> Thank you to all who participated in the discussion!
> Lou
> (as co-chair and doc shepherd)
>
> On 11/20/2018 1:18 PM, Lou Berger wrote:
> > ALL,
> >
> > There is a desire to replace the word "Transport" from the DetNet
> > Transport sub-layer to avoid confusion with L$ Transport protocols.
> >
> > In the TEAS WG we had a similar discussion and we replaced "Transport"
> > with "Traffic Engineered (TE) ".
> >
> > While a bit more verbose, what do people think about this change?
> >
> > To be clear, the suggestion is:
> >
> > OLD
> >
> >                      .
> >                      .
> >        +----------------------------+
> >        |  DetNet Service sub-layer  | PW, UDP, GRE
> >        +----------------------------+
> >        | DetNet Transport sub-layer | IPv6, IPv4, MPLS TE LSPs, MPLS SR
> >        +----------------------------+
> >                      .
> >                      .
> >
> >                    Figure 4: DetNet adaptation to data plane
> >
> > NEW
> >
> >                      .
> >                      .
> >        +----------------------------+
> >        |  DetNet Service sub-layer  | PW, UDP, GRE
> >        +----------------------------+
> >        |      DetNet TE sub-layer   | IPv6, IPv4, MPLS TE LSPs, MPLS SR
> >        +----------------------------+
> >                      .
> >                      .
> >
> >                    Figure 4: DetNet adaptation to data plane
> >
> > Lou
> >
> > On 11/20/2018 11:21 AM, Pascal Thubert (pthubert) wrote:
> >> Hello Lou:
> >>
> >>
> >> About ' discuss changing the name of the "DetNet Transport sub-layer"
> to avoid the word "transport".  '
> >>
> >> For one I'd like to make that call. The unfortunate name collision has
> started to hurt us quite a bit already and people are getting confused on
> very active exchanges we have on the mailing list.
> >>
> >> I tend to agree that for the general IETF "transport" generally means
> "L4". Even point one in your email uses "transport" that way I guess. Sadly
> many alternate names are highly overloaded already (think "carrier" for
> instance, or "bus"). I like the term "train" because of the association
> with a schedule, but that's just me.
> >>
> >> Same goes actually for the complex path that we build. That complex
> path can be an elongated DODAG with multiple PREOF points. Usual terms like
> "circuit" or "path" fail to capture that complexity. 6TiSCH found the term
> "Track" to refer to it.
> >>
> >> Would you push that discussion to the ML?
> >>
> >> Take care,
> >>
> >> Pascal
> >>
> >>> -----Original Message-----
> >>> From: Lou Berger <[e-mail]>
> >>> Sent: mardi 20 novembre 2018 13:11
> >>> To: Scharf, Michael <[e-mail]>
> >>> Cc: [e-mail]; [e-mail]; draft-ietf-detnet-
> >>> [e-mail]
> >>> Subject: Re: [Detnet] Tsvart last call review of
> draft-ietf-detnet-architecture-08
> >>>
> >>> Michael,
> >>>
> >>> I think we're getting somewhere and identifying where we have
> disconnects
> >>> and what may (and what may not) need to change in the document.  My
> >>> takeaways are:
> >>>
> >>> - The document needs a good 'scrub' of the congestion related
> references to
> >>> ensure that the document only makes statements on what is actually done
> >>> within a DetNet and the relationship with transport protocols that use
> detnet
> >>> (which are in fact outside the scope of the DetNet WG).  I'll work
> with the
> >>> authors and WG on this -- I see this change as important, but
> editorial in
> >>> nature.
> >>>
> >>> - We have a perception issue with at least one member of the TSV area
> on the
> >>> meaning and more importantly, implication, of the term "DetNet
> >>> *Transport* sub-layer".  While I don't disagree that a good portion of
> the IETF
> >>> thinks transport protocol (UDP/TCP) when they hear "transport"
> >>> there are plenty others, particularly in the routing area, who
> understand that
> >>> "transport" can refer to Transport Networks.  And Transport Network is
> a well
> >>> understood general industry term. The IETF even has a bunch of RFCs
> that
> >>> relate to Transport networks.  This said, I think it reasonable to go
> back to the
> >>> DetNet WG and discuss changing the name of the "DetNet Transport sub-
> >>> layer"  to avoid the word "transport".  -- BTW we made a parallel
> change in
> >>> the TEAS WG when producing RFC8453.
> >>>
> >>> See below for detail response in-line.
> >>>
> >>> On 11/19/2018 5:15 PM, Scharf, Michael wrote:
> >>>> Lou,
> >>>>
> >>>>> --
> >>>>> I wanted to take a step back from the multiple discussions that were
> >>>>> spawned by your review -- from a doc shepherd perspective, and see
> >>>>> where we are.   I know that the authors have sent a -09 version that
> >>>>> addresses some, but not all issues.
> >>>>>
> >>>>>     From the exchanges I've seen, I think the key remaining issues
> are
> >>>>> related to:
> >>>>>
> >>>>> (a) possibly introduction of congestion in the general internet if
> >>>>> packets were somehow to escape a detnet domain.  The source of this
> >>>>> congestion would be inelastic traffic using DetNet or due to
> >>>>> congestion loss that is masked by PREOF.
> >>>> These are two major issues that need to be addressed. Note that it
> may not
> >>> be sufficient just to add a section on operational and deployment
> >>> considerations. Also the existing text in the document will need to
> get aligned
> >>> to normative guidance on how to avoid a congestion collapse.
> >>>> In -09, one example would be Section 3.1. "Primary goals defining the
> >>> DetNet QoS"
> >>>>       Congestion protection operates by allocating resources along
> the path
> >>>>       of a DetNet flow, e.g., buffer space or link bandwidth.
> Congestion
> >>>>       protection greatly reduces, or even eliminates entirely, packet
> loss
> >>>>       due to output packet congestion within the network, but it can
> only
> >>>>       be supplied to a DetNet flow that is limited at the source to a
> >>>>       maximum packet size and transmission rate.  Note that congestion
> >>>>       protection provided via congestion detection and notification is
> >>>>       explicitly excluded from consideration in DetNet, as it serves a
> >>>>       different set of applications.
> >>>> At least the last sentence would contradict a better discussion of
> congestion
> >>> in the document. For instance, it could just be removed. In any case,
> the
> >>> current wording in the last sentence is not correct, as the IETF term
> for what is
> >>> described in the last sentence is "congestion control".
> >>>> Another example would be  Section 3.2.1.1. "Eliminate congestion loss"
> >>>>
> >>>>       The primary means by which DetNet achieves its QoS assurances
> is to
> >>>>       reduce, or even completely eliminate, congestion within a
> DetNet node
> >>>>       as a cause of packet loss.  This can be achieved only by the
> >>>>       provision of sufficient buffer storage at each node through the
> >>>>       network to ensure that no packets are dropped due to a lack of
> buffer
> >>>>       storage.  Note that a DetNet flow cannot be throttled, i.e., its
> >>>>       transmission rate cannot be reduced via explicit congestion
> >>>>       notification.
> >>>>
> >>>> This section IMHO has to include a discussion of what happens in the
> (not
> >>> expected) case that packets get dropped or that ECN marks are
> received. It is
> >>> understood that this would not happen in normal operation of a DetNet
> >>> network, but I believe just considering the error-free operation of a
> DetNet
> >>> network is not sufficient for this document. At least for the risk of
> traffic that
> >>> may escape from a DetNet network is inherently not sufficient to
> assume that
> >>> the DetNet network is always error-free.
> >>>
> >>> I think these are examples of text that needs to be cleanup up and to
> >>> delineate what is done with a DetNet.
> >>>
> >>>
> >>>> As a result, addressing my concerns will most likely require editing
> several
> >>> parts of the document.
> >>>> In addition, I'd like to emphasize that my review comment "It is
> surprising
> >>> that there is hardly any discussion on network robustness and safety"
> >>>
> >>> I have no idea what you mean by safety here.  Can you elaborate.
> >>>
> >>>
> >>>> covers more than just inelastic traffic that escapes from a DetNet
> network
> >>> and masking of packet loss. Given that DetNet traffic may be extremely
> critical
> >>> traffic, I really wonder why the document doesn't emphasize more the
> >>> required robustness against failures *inside* the DetNet network as
> well as
> >>> counter-measures. But this is something the WG needs to decide. As
> TSV-ART
> >>> reviewer, I will be fine if the document clearly describes how the
> impact of
> >>> failures will be isolated inside the DetNet network and will not put
> the general
> >>> Internet at risk.
> >>>
> >>> I agree - I think, the document should be clear on it's scope and
> >>> relationship to general internet usage.
> >>>
> >>>
> >>>>> (b) The use of the term 'transport' in DetNet to refer to what is
> >>>>> basically a Traffic Engineered sub-network layer, such as is provided
> >>>>> with MPLS-TE or Optical Transport Networks.
> >>>> In the Internet architecture, the term 'transport' refers to Internet
> transport
> >>> protocols. I doubt that the document can avoid discussing the
> implications of
> >>> and interactions with Internet transport protocols such as UDP or TCP.
> As a
> >>> result, I disagree that the document can use the term 'transport' to
> refer to
> >>> traffic engineered sub-network layers.
> >>>
> >>> I think this is covered by my comment above.
> >>>
> >>>
> >>>>    From a TSV-ART point of view, the document can either only use the
> term
> >>> "transport" for Internet transport protocols and use another term for
> sub-
> >>> network layers (as handled in the *routing* area of the IETF), or the
> document
> >>> has to clearly distinguish between the Internet transport layer and
> other uses
> >>> of the term "transport" and explain the overlap. I believe the former
> would be
> >>> less confusing, but I will leave it up to the TSV ADs to discuss
> terminology
> >>> overlap in the IESG. As TSV-ART reviewer I insist that the document
> uses the
> >>> terms "transport layer" and "transport protocol" only when referring
> to the
> >>> Internet transport layer.
> >>>
> >>> I'm personally okay with a name change and even willing to push this
> >>> discussion within the WG, but as said above, "Transport Network" is a
> >>> generally understood industry term that is also used in RFCs -- so
> we'll
> >>> have to see what where WG consensus ends up.
> >>>
> >>>>> Do you have any other issues that that are critical to be addressed
> >>>>> before this work moves forward?  If so which?
> >>>> Regarding Section 4.4 I have already deferred the discussion to the
> IESG. The
> >>> TSV-ART review comment is that the IESG needs to carefully look at the
> >>> concepts, terminology, and references in section 4.4.
> >>>> Regarding my other comments, I acknowledge that -09 is a step
> forward. But
> >>> given the cross-dependencies e.g. regarding terminology and
> definitions, I will
> >>> need to read the text completely once there is a proposal how to
> address my
> >>> review. As noted in my review, I believe the document must use
> terminology
> >>> clearly and consistently. As example, a statement in -09 such as
> "Network
> >>> nodes supporting DetNet flows have to implement some of the DetNet
> >>> capabilities (not necessarily all) in order to treat DetNet flows such
> that their
> >>> QoS requirements are met" is IMHO too vague. But in such cases it
> depends
> >>> whether there is precise normative guidance elsewhere. And this
> requires
> >>> looking at the text as a whole.
> >>>
> >>> I think the next steps lie with me and the WG.  We'll let you know once
> >>> there is a new version.  Of course, you can also contribute to the WG
> >>> discussion on the topic.
> >>>
> >>> Thanks,
> >>>
> >>> Lou
> >>>
> >>>> Best regards
> >>>>
> >>>> Michael
> >>>>
> >>>>
> >>>>
> >>>>> Thank you,
> >>>>>
> >>>>> Lou
> >>>>>
> >>>>> On 9/28/2018 6:24 PM, Michael Scharf wrote:
> >>>>>> Reviewer: Michael Scharf
> >>>>>> Review result: Ready with Issues
> >>>>>>
> >>>>>> The document "Deterministic Networking Architecture"
> >>>>>> (draft-ietf-detnet-architecture-08) defines an overall framework for
> >>>>>> Deterministic Networking.
> >>>>>>
> >>>>>> As TSV-ART reviewer, I believe that this document has issues as
> >>>>> detailed below.
> >>>>>> Michael
> >>>>>>
> >>>>>> Major issues:
> >>>>>>
> >>>>>> * It seems that DetNet cannot easily be deployed in the Internet
> >>>>> without
> >>>>>> additional means. Thus, for a baseline document, one could expect
> >>>>> some
> >>>>>> explanation on the requirements of deploying DetNet in a network.
> >>>>> DetNet
> >>>>>> basically requires support in (almost) all network devices
> >>>>> transporting DetNet
> >>>>>> traffic. That assumption should be explicitly spelt out early in the
> >>>>> document,
> >>>>>> e.g., in the introduction. There also needs to be an explicit
> >>>>> discussion of the
> >>>>>> implications if not the whole network is aware of or supports
> DetNet.
> >>>>> There is
> >>>>>> some text in Section 4.2.2 and Section 4.3.3, but I believe
> >>>>> additional explicit
> >>>>>> discussion is needed at a prominant place. For instance, can use of
> >>>>> DetNet do
> >>>>>> harm to parts of a network not supporting DetNet? As a side note,
> >>>>> when TCPM
> >>>>>> published RFC 8257, the following disclaimer was added: "DCTCP, as
> >>>>> described in
> >>>>>> this specification, is applicable to deployments in controlled
> >>>>> environments
> >>>>>> like data centers, but it must not be deployed over the public
> >>>>> Internet without
> >>>>>> additional measures." I wonder if a similar disclaimer is needed for
> >>>>> DetNet. If
> >>>>>> there is an implicit assumption that DetNet will  be used in
> >>>>> homogenous
> >>>>>> environments with mostly DetNet-aware devices within the same
> >>>>> organization,
> >>>>>> such an assumption should be made explicit.
> >>>>>>
> >>>>>> * It is surprising that there is hardly any discussion on network
> >>>>> robustness
> >>>>>> and safety; this probably also relates to security. For instance,
> >>>>>> misconfiguration or errors of functions performing packet
> replication
> >>>>> could
> >>>>>> severely and permantly congest a network and cause harm. How does
> the
> >>>>> DetNet
> >>>>>> architecture ensure that a network stays fully operational e.g. if
> >>>>> the topology
> >>>>>> changes or there are equipment failures? Probably this can be solved
> >>>>> by
> >>>>>> implementations (e.g., dynamic control plane), but why are
> >>>>> corresponding
> >>>>>> requirements not spelt out? Section 3.3.2 speculates that filters
> and
> >>>>> policers
> >>>>>> can help, and that may be true, but that probably still assumes
> >>>>> consistently
> >>>>>> and correctly configured (and well-behaving) devices. And Section
> >>>>> 3.3.2 is
> >>>>>> vague and mentions a "infinite variety of possible failures" without
> >>>>> stating
> >>>>>> any requirements or recommendations. There may be further solutions,
> >>>>> such as
> >>>>>> circuit breakers and the like. Why are such topics not discussed?
> >>>>>>
> >>>>>> * Somewhat related, the document only looks at impact of failures to
> >>>>> the QoS of
> >>>>>> DetNet traffic. What is missing is a discussion how to protect non-
> >>>>> DetNet parts
> >>>>>> of a network from any harm caused by DetNet mechanisms. Solutions to
> >>>>> this
> >>>>>> probably exist. But why is the impact on non-DetNet traffic (e.g.,
> in
> >>>>> case of
> >>>>>> topology changes or failures of DetNet functions) not discussed at
> >>>>> all in the
> >>>>>> document?
> >>>>>>
> >>>>>> * Regarding security, an architecture like DetNet probably requires
> >>>>> that only
> >>>>>> authenticated and authorized end systems have access to the data
> >>>>> plane. The
> >>>>>> security considerations only briefly mention the control aspect
> ("the
> >>>>>> authentication and authorization of the controlling systems").
> >>>>>>
> >>>>>> * For an architecture document, the lack of clarity and consistency
> >>>>> regarding
> >>>>>> terminology is concerning. This specifically applies to the case of
> >>>>> incomplete
> >>>>>> networks (as per Section 4.2.2 and 4.3.3) that include "DetNet-
> >>>>> unaware nodes".
> >>>>>> The document introduces terms such as "DetNet intermediate nodes"
> but
> >>>>> then
> >>>>>> repeatedly uses generic terms such as "node" or "hop" that may
> >>>>> include
> >>>>>> DetNet-unaware nodes. For instance, for incomplete networks, a
> >>>>> sentence such as
> >>>>>> "The primary means by which DetNet achieves its QoS assurances is to
> >>>>> reduce, or
> >>>>>> even completely eliminate, congestion within a node as a cause of
> >>>>> packet loss"
> >>>>>> seems to only apply to "DetNet transit nodes" but not
> "DetNet-unaware
> >>>>> nodes".
> >>>>>> Similar ambiguity exist for other use of the terms "hop" and "node",
> >>>>> which may
> >>>>>> or may not include DetNet-unaware nodes. It is unclear why the
> >>>>> document does
> >>>>>> not consistently use the terminology introduced in Section 2.1 in
> all
> >>>>> sections
> >>>>>> and clearly distinguishes cases with and without DetNet support.
> >>>>>>
> >>>>>> * Section 4.4 refers to RFC 7426, which is an informational RFC on
> >>>>> IRTF stream,
> >>>>>> and the document uses the concepts introduced there (e.g.,
> "planes").
> >>>>> This is
> >>>>>> very confusing. First, an IETF Proposed Standard should probably
> >>>>> refer to
> >>>>>> documents having IETF consensus. An example would be RFC 7491,
> albeit
> >>>>> there is
> >>>>>> other related work as well, e.g., in the TEAS WG. Second, Section
> 4.4
> >>>>> is by and
> >>>>>> large decoupled from the rest of the document and not specific to
> >>>>> DetNet.
> >>>>>> Neither do other sections of the document refer to the concepts
> >>>>> introduced in
> >>>>>> Section 4.4, nor does Section 4.4 use the DetNet terminology or
> >>>>> discuss
> >>>>>> applicability to DetNet. Section 4.4 even mentions explicitly at the
> >>>>> end that
> >>>>>> it discusses aspects that are orthogonal to the DetNet architecture.
> >>>>> It is not
> >>>>>> at all clear why Section 4.4 is in this document. Section 4.4 could
> >>>>> be removed
> >>>>>> from the document without impacting the rest of the document.
> >>>>>>
> >>>>>> Minor issues:
> >>>>>>
> >>>>>> * Terminology "DetNet transport layer"
> >>>>>>
> >>>>>>       The term "transport layer" has a well-defined meaning in the
> IETF,
> >>>>> e.g.
> >>>>>>       originating from RFC 1122. While "transport" and e.g.
> "transport
> >>>>> network" is
> >>>>>>       used in the IETF for different technologies in different
> areas, I
> >>>>> think the
> >>>>>>       term "transport layer" is typically understood to refer to
> >>>>> transport
> >>>>>>       protocols such as TCP and UDP. As such, I personally find the
> term
> >>>>> "DetNet
> >>>>>>       transport layer" misleading and confusing. The confusion is
> easy
> >>>>> to see e.g.
> >>>>>>       in Figure 4, where UDP (which is a transport protocol as per
> RFC
> >>>>> 1122) sits
> >>>>>>       on top of "transport".
> >>>>>>
> >>>>>>       Based on the document it also may be solution/implementation
> >>>>> specific whether
> >>>>>>       the "DetNet transport layer" is actually a separate protocol
> layer
> >>>>> compared
> >>>>>>       to the "DetNet service layer". Thus it is not clear to me why
> the
> >>>>> word
> >>>>>>       "layer" has to be used, specifically in combination "transport
> >>>>> layer".
> >>>>>>       To me as, the word "transport layer" (and "transport
> protocol")
> >>>>> should be
> >>>>>>       used for protocols defined in TSV area, consistent with RFC
> 1122.
> >>>>> But this is
> >>>>>>       probably a question to be sorted out by the IESG.
> >>>>>>
> >>>>>> * Page 9
> >>>>>>
> >>>>>>        A DetNet node may have other resources requiring allocation
> >>>>> and/or
> >>>>>>        scheduling,
> >>>>>>
> >>>>>>       This is just one of several examples for inconsistent use of
> >>>>> terminology.
> >>>>>>       What is a "DetNet node"? That term is not introduced in
> Section
> >>>>> 2.1
> >>>>>> * Page 14
> >>>>>>
> >>>>>>        A DetNet network supports the dedication of a high proportion
> >>>>> (e.g.
> >>>>>>        75%) of the network bandwidth to DetNet flows.
> >>>>>>
> >>>>>>       The 75% value is not reasoned. What prevents using 99% of the
> >>>>> bandwidth for
> >>>>>>       DetNet traffic?
> >>>>>>
> >>>>>> * Page 15: Figure 2
> >>>>>>
> >>>>>>       If the term "transport layer" cannot be avoided, the labels in
> >>>>> this figure
> >>>>>>       should at least be expanded to "DetNet transport layer".
> >>>>>>
> >>>>>> * Page 18: Figure 4
> >>>>>>
> >>>>>>       As already mentioned earlier, Figure 4 is confusing. UDP is a
> >>>>> transport
> >>>>>>       protocol. If the term "transport" cannot be avoided, the
> labels in
> >>>>> this
> >>>>>>       figure should at least be expanded to "DetNet transport".
> >>>>>>
> >>>>>> * Page 23
> >>>>>>
> >>>>>>        If the source transmits less data than this limit
> >>>>>>        allows, the unused resource such as link bandwidth can be
> made
> >>>>>>        available by the system to non-DetNet packets.
> >>>>>>
> >>>>>>       Could there be additional requirements on the use of unused
> >>>>> resources by
> >>>>>>       non-DetNet packets, e.g., regarding preemption? I am just
> >>>>> wondering... If
> >>>>>>       that was possible, a statement like "... can be made
> available by
> >>>>> the system
> >>>>>>       to non-DetNet packets as long as all guarantees are fulfilled"
> >>>>> would be on
> >>>>>>       the safe side, no?
> >>>>>>
> >>>>>> * Page 27:
> >>>>>>
> >>>>>>        DetNet achieves congestion protection and bounded delivery
> >>>>> latency by
> >>>>>>        reserving bandwidth and buffer resources at every hop along
> the
> >>>>> path
> >>>>>>        of the DetNet flow.
> >>>>>>
> >>>>>>       Why does this sentence use the word "hop"? As far as I
> understand,
> >>>>> in DetNet
> >>>>>>       bandwidth and buffer resources are reserved in each DetNet
> >>>>> intermediate node.
> >>>>>>       If there were hops over IP routers not being DetNet
> intermediate
> >>>>> nodes, no
> >>>>>>       resources would be reserved there. As per Section 4.3.3, it is
> >>>>> possible to
> >>>>>>       deploy DetNet this way. And obviously there can be resource
> >>>>> bottlenecks below
> >>>>>>       IP, on devices that are not routers... So does "hop" here
> refer to
> >>>>> IP router
> >>>>>>       hops or also to devices not processing IP (or IP/MPLS)?
> >>>>>>
> >>>>>> * Page 27:
> >>>>>>
> >>>>>>        Standard queuing and transmission selection algorithms allow
> a
> >>>>>>        central controller to compute the latency contribution of
> each
> >>>>>>        transit node to the end-to-end latency, ...
> >>>>>>
> >>>>>>       The text does not explain why a _central_ controller is
> needed for
> >>>>> this
> >>>>>>       computation. Why would a distributed control plane not be
> able to
> >>>>> realize
> >>>>>>       this computation. Isn't this implementation-specific?
> >>>>>>
> >>>>>> * Page 32
> >>>>>>
> >>>>>>       To somebody who is not deeply familiar with DetNet, it is
> >>>>> impossible to parse
> >>>>>>       the description of the examples in Section 4.7.3. For
> instance,
> >>>>> "VID +
> >>>>>>       multicast MAC address" is not introduced. I think this example
> >>>>> must be
> >>>>>>       expaned with additional context and explanation to be useful
> to
> >>>>> readers.
> >>>>>> * Page 34
> >>>>>>
> >>>>>>        There are three classes of information that a central
> controller
> >>>>> or
> >>>>>>        distributed control plane needs to know that can only be
> obtained
> >>>>>>        from the end systems and/or nodes in the network.
> >>>>>>
> >>>>>>       Wouldn't it be sufficient to state "Provisioning of DetNet
> >>>>> requires knowledge
> >>>>>>       about ...". Does it matter in this context whether the
> >>>>> provisioning is done
> >>>>>>       by a central controller or a distributed control plane? For
> >>>>> instance, could
> >>>>>>       the same paragraph also apply to a network that uses
> _multiple_
> >>>>> central
> >>>>>>       controllers, or hybrid combinations of central controllers and
> >>>>> distributed
> >>>>>>       control planes? In general, an architecture document should be
> >>>>> agnostic to
> >>>>>>       implementation aspects unless there is a specific need. In
> this
> >>>>> specific
> >>>>>>       case, I fail to see a need to discuss the realization of the
> >>>>> control plane of
> >>>>>>       a network.
> >>>>>>
> >>>>>> Editorial nits:
> >>>>>>
> >>>>>> * Page 9:
> >>>>>>
> >>>>>>        The low-level mechanisms described in Section 4.5 provide the
> >>>>>>        necessary regulation of transmissions by an end system or
> >>>>>>        intermediate node to provide congestion protection.  The
> >>>>> allocation
> >>>>>>        of the bandwidth and buffers for a DetNet flow requires
> >>>>> provisioning
> >>>>>>        A DetNet node may have other resources requiring allocation
> >>>>> and/or
> >>>>>>        scheduling, that might otherwise be over-subscribed and
> trigger
> >>>>> the
> >>>>>>        rejection of a reservation.
> >>>>>>
> >>>>>>       Probably a full stop is missing after "provisioning".
> >>>>>>
> >>>>>> * Page 11: "... along separate (disjoint non-SRLG) paths ..."
> >>>>>>
> >>>>>>       I find this confusing. I would understand e.g. "along separate
> >>>>>>       (SRLG-disjoint) paths".
> >>>>>>
> >>>>>> * Page 34:
> >>>>>>
> >>>>>>        When using a peer-
> >>>>>>        to-peer control plane, some of this information may be
> required
> >>>>> by a
> >>>>>>        system's neighbors in the network.
> >>>>>>
> >>>>>>       Would "acquired" be a better term?
> >>>>>>
> >>>>>> * Page 34:
> >>>>>>
> >>>>>>        o  The identity of the system's neighbors, and the
> >>>>> characteristics of
> >>>>>>           the link(s) between the systems, including the length (in
> >>>>>>           nanoseconds) of the link(s).
> >>>>>>
> >>>>>>       "Latency" or "delay" would probably be a better terms if the
> value
> >>>>> is
> >>>>>>       measured in nanoseconds.
> >>>>>>
> >>>>>> * Page 35:
> >>>>>>
> >>>>>>        DetNet is provides a Quality of Service (QoS), and as such,
> does
> >>>>> not
> >>>>>>        directly raise any new privacy considerations.
> >>>>>>
> >>>>>>       Broken sentence
> >>>>>>
> >>>>>> * Please expand acronyms on first use (e.g., OTN)
> >>>>>>
> >>>>>>
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