[alto] FW: Benjamin Kaduk's No Objection on draft-ietf-alto-cost-calendar-20: (with COMMENT)

"Randriamasy, Sabine (Nokia - FR/Paris-Saclay)" <sabine.randriamasy@nokia-bell-labs.com> Tue, 17 March 2020 16:01 UTC

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From: "Randriamasy, Sabine (Nokia - FR/Paris-Saclay)" <sabine.randriamasy@nokia-bell-labs.com>
To: Benjamin Kaduk <kaduk@mit.edu>, The IESG <iesg@ietf.org>
CC: "draft-ietf-alto-cost-calendar@ietf.org" <draft-ietf-alto-cost-calendar@ietf.org>, "alto-chairs@ietf.org" <alto-chairs@ietf.org>, IETF ALTO <alto@ietf.org>, Vijay Gurbani <vijay.gurbani@gmail.com>, "vijay.gurbani@nokia.com" <vijay.gurbani@nokia.com>
Thread-Topic: Benjamin Kaduk's No Objection on draft-ietf-alto-cost-calendar-20: (with COMMENT)
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Subject: [alto] FW: Benjamin Kaduk's No Objection on draft-ietf-alto-cost-calendar-20: (with COMMENT)
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Hi Benjamin,

Thanks again for your review and guidance. Your comments have been addressed as described in the responses inline. 
A new version v21 has been posted and is available here, hoping it meets your expectations.
https://tools.ietf.org/html/draft-ietf-alto-cost-calendar-21  

Best regards,
Sabine 

-----Original Message-----
From: Randriamasy, Sabine (Nokia - FR/Paris-Saclay) <sabine.randriamasy@nokia-bell-labs.com> 
Sent: Wednesday, March 11, 2020 7:18 PM
To: Benjamin Kaduk <kaduk@mit.edu>du>; The IESG <iesg@ietf.org>
Cc: draft-ietf-alto-cost-calendar@ietf.org; alto-chairs@ietf.org; alto@ietf.org; Vijay Gurbani <vijay.gurbani@gmail.com>om>; vijay.gurbani@nokia.com
Subject: RE: Benjamin Kaduk's No Objection on draft-ietf-alto-cost-calendar-20: (with COMMENT)

Hello Benjamin,

Thanks again for your review. A version v21 is under edition to finish addressing all the review comments. 
Please see inline for my responses to your comments. 

Best regards,
Sabine

>-----Original Message-----
>From: Benjamin Kaduk via Datatracker <noreply@ietf.org>
>Sent: Tuesday, March 10, 2020 1:21 AM
>To: The IESG <iesg@ietf.org>
>Cc: draft-ietf-alto-cost-calendar@ietf.org; alto-chairs@ietf.org; 
>alto@ietf.orgorg; Vijay Gurbani <vijay.gurbani@gmail.com>om>; 
>vijay.gurbani@nokia.com
>Subject: Benjamin Kaduk's No Objection on draft-ietf-alto-cost-calendar-20:
>(with COMMENT)
>
>Benjamin Kaduk has entered the following ballot position for
>draft-ietf-alto-cost-calendar-20: No Objection
>
>
>----------------------------------------------------------------------
>COMMENT:
>----------------------------------------------------------------------
>
>Thanks for adding text about the incompatibility of constraints with 
>the calendar functionality.  I would suggest further clarifying that 
>this reflects a limitation of this method or reduction in functionality 
>when compared to RFC
>7285 (and 8189), but do not insist upon it.
>
[[SR]] Most of your text was used, thanks, and added to the text on constraints in section 3.3:
----- NEW
As providing the constraint functionality in conjunction 
   with the Calendar functionality is not feasible for the reasons described above, 
   the two features are mutually exclusive. The absence of constraints on 
   Filtered Cost Map and Endpoint Cost Map Calendars 
   reflects a divergence from the non-calendared information resources defined in 
   <xref target="RFC7285"/> and extended in <xref target="RFC8189"/>, 
that support optional constraints.
----- END

>[comments from -19 preserved for posterity]
>
>Section 1
>
>   In this document, an "ALTO Cost Calendar" is specified in terms of
>   information resources capabilities that are applicable to time-
>
>nit: "information resources capabilities" has two plurals.  Either make 
>"resources" possessive ("resources'") or just use "resource".
[ [SR] ] done thanks

>Section 1.1
>
>I'm not sure how much *archival* value there is in the current 
>discussion of SENSE and Unicorn.
>
[ [SR] ] Text was changed to be less project-centric and instead focusing on the motivating use-case. 
Reference [I-D.xiang-alto-multidomain-analytics] was changed to an archived journal paper [Unicorn-fgcs].

>Section 3.1
>
>   sent to the ALTO Clients needing it.  The "ALTO Incremental Updates
>   Using Server-Sent Events (SSE)" Service
>   [I-D.ietf-alto-incr-update-sse] can be used to update the calendar
>   faster if supported by both the Server and the Client.
>
>nit(?): faster than what?
>
[ [SR] ] the text has been changed as follows in v20:
NEW
The "ALTO Incremental Updates
   Using Server-Sent Events (SSE)" Service
   [I-D.ietf-alto-incr-update-sse] can be used to directly update the
   Calendar upon value changes, if supported by both the Server and the
   Client. END
>
>Section 3.3
>
>   The present document extends the definition of a legacy cost map
>   given in [RFC7285] to allow a cost entry to be an array of values,
>   with one value one per time interval, instead of being just one
>   number.  Therefore the implementor of this extension MUST consider
>   that a cost entry is an array of values.  Specifically, an
>
>nit: this is not quite true, strictly speaking -- the cost entry is 
>only an array when the cost calendar functionality is active, which is 
>not a subset of when the extension is implemented.
>Also, if the cost entry is definitively an array, then this would be 
>replacing the definition, not extending it.
>
[ [SR] ] Would the following text be better?
NEW
The present document extends the
   definition of a legacy cost map given in [RFC7285] to allow a cost
   entry to be an array of values, with one value one per time interval, instead of
   being just one number, when the Cost Calendar functionality is activated on this cost.
   Therefore the implementor of this extension MUST consider that a cost entry is an array of values
   if this cost has been queried as a Calendar. END

>
>   implementation of this extension MUST parse the "number-of-intervals"
>   attribute of the "calendar-attributes" in an IRD entry announcing a
>   service providing Cost Calendar.  The implementation then will know
>   that a cost entry of the service will be an array of values, and the
>   expected size of the array is that specified by the "number-of-
>   intervals" attribute.
>
>Is it a protocol error if the cost entry is a scalar or an array of 
>different size than expected?  Where do we specify error handling for those cases?
>
[[SR]]
There is actually no way for a Client to notify a Server that the size of the received array is not as expected.
So, the text you quoted a paragraph has been adapted and augmented with rules attempting to address this case. 
It has been added after the text you quoted, as follows:
----- NEW
Specifically, an implementation of this extension MUST parse the
   "number-of-intervals" attribute of the "calendar-attributes" in an
   IRD entry announcing a service providing  a Cost Calendar for a given
   cost type.  The implementation then will know that a cost entry of
   the service will be an array of values, and the expected size of the
   array is that specified by the "number-of-intervals" attribute.  The
   following rules attempt to ensure consistency between the array size
   announced by the Server and the actual size of the array received by
   the Client:

   o  The size of the array of values conveyed in a Cost Calendar and
      received by the Client MUST be equal to the value of attribute
      "number-of-intervals" indicated in the IRD for the requested cost
      type.

  o  When the size of the array received by the Client is different
      from the expected size, the Client SHOULD ignore the received
      array.
----- END

>   To realize an ALTO Calendar, this document extends: the IRD and the
>   ALTO requests and responses for Cost Calendars.
>
>nit: no colon needed.
[ [SR] ] done, thanks
>

>   o  it allows an ALTO Server to offer Calendar capabilities on a cost
>      type, with attributes values adapted to each information resource.
>
>I'm not entirely sure what this is intending to say.  Is the idea that 
>this is a general mechanism that could be applied to capabilities of 
>all cost types (as opposed to, e.g., making a new cost mode for 
>"calendar of numerical" that would need many new types to support different types of calendar)?
>
[[SR]] The idea is that the attributes specifying the time granularity of a Calendar are not globally tied with 
a cost type but with a cost type within a resource. The text has been updated in 2 steps:

- Step 1: 3rd bullet you quoted was modified as follows:
----- NEW
it allows an ALTO Server to offer, for a cost type, different
      Calendars with attributes that are specific to the information
      resources providing a Calendar for this cost type, instead of
      being globally specific to the cost type.
----- END

- Step 2: after the 2 other bullets and the next paragraph, a new paragraph was added:
----- NEW
Since Calendar attributes are specific to an information resource, a
   Server may adapt the granularity of the calendared information so as
   to moderate the volume of exchanged data.  For example: suppose a
   Server provides a Calendar for cost type name "routingcost".  The
   Server may offer a Calendar in a Cost Map resource, which may be a
   voluminous resource, as an array of 6 intervals lasting each 4 hours. 
It may also offer a Calendar in an Endpoint Cost Map resource, 
   which is potentially less voluminous, as a finer-grained array of 24 intervals lasting 1 hour each.
----- END

>Section 3.3.2
>
>   The ALTO protocol extensions for Cost Calendars have been defined so
>   as to ensure that Calendar capable ALTO Servers can provide legacy
>
>nit: hyphenate "Calendar-capable" (and similarly throughout).  I see 
>that "calendar-aware" is already hyphenated, which is good.
[ [SR]   ] done in v20 thanks

>
>   ALTO Clients with legacy information resources as well.  That is, a
>   legacy ALTO Client can request resources and receive responses as
>   specified in [RFC7285].
>
>Should we say anything about Calendar-aware ALTO Clients being able to 
>get useful responses from legacy Servers as well?
>
[ [SR]   ] Agree. The following sentence has been added after paragraph 2:
NEW
   A Calendar-aware ALTO Client MUST implement the base protocol
   specified in <xref target="RFC7285"/>.
END

>
>Section 4
>
>   The Calendar attributes in the IRD information resources capabilities
>   carry constant dateless values.  A Calendar is associated with an
>
>"constant" in what sense?
>
[ [SR]   ] Agree, the main idea is that the attribute values are dateless. So "constant" has been removed:
----- NEW
The Calendar attributes in the IRD information resources capabilities carry dateless values.
----- END
>
>Section 4.1
>
>   types.  A cost type name MUST NOT appear more than once in the
>   "calendar-attributes" member of a resource entry; multiple
>   appearances of a cost type name in the CalendarAttributes object of
>   the "calendar-attributes" member MUST cause the ALTO Client to ignore
>   any occurrences of this name beyond the first encountered occurrence.
>
>It seems that this is most important in that the given resource entry 
>has an array of calendar-attributes, and we need to know which element 
>of that array to use when processing calendars for that cost type.
>Indicating the extra layer of structure in the description around this 
>requirement would help the reader.
>
[[SR]] Hoping I understood your comment, paragraph 1 has been updated as follows:
----- NEW
A Cost Calendar for a given cost type MUST be indicated in the IRD by
   an object of type CalendarAttributes.  A CalendarAttributes object is
   represented by the "calendar-attributes" member of a resource entry.
   Member "calendar-attributes" is an array of CalendarAttributes
   objects.  Each CalendarAttributes object lists a set of one or more
   cost types it applies to.  A cost type name MUST NOT appear more than
   once in the "calendar-attributes" member of a resource entry;
   multiple appearances of a cost type name in the CalendarAttributes
   object of the "calendar-attributes" member MUST cause the ALTO Client
   to ignore any occurrences of this name beyond the first encountered
   occurrence.  The Client SHOULD consider the CalendarAttributes object
   in the array containing the first encountered occurrence of a cost
   type as the valid one for this cost type.  As an alternative, the
   Client may want to avoid the risks of erroneous guidance associated
   to the use of potentially invalid Calendar values.  In this case, the
   Client MAY ignore the totality of occurences of CalendarAttributes
   objects containing the cost type name and query the cost type using
   [RFC7285].
----- END

Please note that to address a similar comment by Francesca Palombini, 
a paragraph providing guidance to Clients in such a case has been added at the end of the security section 7.

>   An ALTO Server SHOULD specify the "time-interval-size" in the IRD as
>   the smallest it is able to provide.  A Client that needs a longer
>   interval can aggregate multiple cost values to obtain it.
>
>nit: we haven't defined "time-interval-size" yet, so either moving this 
>later or giving a bit more explanation might be useful.
>
[ [SR] ] Agree. This text was moved right after the definition of CalendarAttributes

>
>   o  "cost-type-names":
>
>      *  An array of one or more elements indicating the cost-type-names
>         in the IRD entry to which the capabilities apply.
>
>Which capabilities?
>
[ [SR] ] The text was clarified as follows:
NEW
An array of one or more elements indicating the cost-type-names
         in the IRD entry to which the values of "time-interval-size" and 
         "number-of-intervals" apply.
END

>
>      *  is the duration of an ALTO Calendar time interval in a unit of
>         seconds.  A "time-interval-size" value contains a non-negative
>         JSONNumber.  Example values are: 300 and 7200, meaning that
>         each Calendar value applies on a time interval that lasts 5
>         minutes and 2 hours, respectively.  Since an interval size
>         (e.g., 100 ms) can be smaller than the unit, the value
>         specified may be a floating point (e.g., 0.1).  Both ALTO
>         Clients and Servers should be aware of potential precision
>         issues caused by using floating point numbers; for example, the
>         floating number 0.1 cannot be represented precisely using a
>         finite number of binary bits.  To improve interoperability and
>         be consistent with [RFC7285] on the use of float point numbers,
>         the Server and the Client SHOULD use IEEE 754 double-precision
>         floating point [IEEE.754.2008] to store this value.
>
>nit: please be consistent about using "floating-point number" (vs., 
>e.g., "floating point" or "float point").
[ [SR] ] thanks, used "floating" everywhere

>
>   - Providing attribute "cost-type-names" together with "time-interval-
>   size" and "number-of-intervals" improves the readability of the
>   Calendar attributes specified for an IRD resource and avoids
>   confusion with Calendar attributes of other cost types.
>
>I'm not sure I understand either of these points (how readability is 
>helped and how confusion is avoided).
>
[ [SR] ] Indeed the text was clarified as follows in v20, as readability was not the main point:
NEW
- Attribute "cost-type-names" is associated with "time-interval-size" and 
   "number-of-intervals", because multiple cost types may share the same 
   values for attributes "time-interval-size" and "number-of-intervals". 
   To avoid redundancies, cost type names sharing the same values for "time-interval-size" 
   and "number-of-intervals" are grouped in the "cost-type-names" attribute. 
   In the example IRD provided in <xref target="sect-4.3"/>, the information resource 
   “filtered-cost-map-calendar” provides a Calendar for cost type names 
   "num-routingcost", "num-throughputrating" and "string-servicestatus".  
   Cost type names "num-routingcost" and "num-throughputrating" are 
   grouped in the "cost-type-names" attribute because they share the 
   same values for "time-interval-size" and "number-of-intervals", 
   which are respectively 7200 and 12.
END

>
>Section 4.2
>
>   It may be useful to distinguish IRD resources supported by the base
>   ALTO protocol from resources supported by its extensions.  To achieve
>   this, one option, is that a "root" ALTO Server implementing base
>   protocol resources and running at a given domain, delegates
>   "specialized" information resources such as the ones providing Cost
>   Calendars, to another ALTO Server running in a subdomain.  The "root"
>
>How would a Client know that this mechanism is in use?
>
[[SR]] would the following update clarify? 
----- NEW
..... Cost Calendars, to another ALTO Server running in a subdomain.  The "root" ALTO Server
can provide a Calendar-specific resource entry, that has a media-type 
   of "application/alto-directory+json" and that specifies the 
   URI allowing to retrieve the location of a Calendar-aware Server and 
   discover its resources.
----- END

>   This document provides an example, where a "root" ALTO Server runs in
>   a domain called "alto.example.com".  It delegates the announcement of
>   Calendars capabilities to an ALTO Server running in a subdomain
>   called "custom.alto.example.com".  The location of the "delegate
>   Calendar IRD" is assumed to be indicated in the "root" IRD by the
>   resource entry: "custom-calendared-resources".
>
>This is "assumed" only for the purpose of the example, and not as a 
>general protocol mechanism, right?
>
[[SR]] yes, right

>   Another benefit of delegation is that some cost types for some
>   resources may be more advantageous as Cost Calendars and it makes few
>   sense to get them as a single value.  For example, if a cost type has
>   predictable and frequently changing values, calendared in short time
>   intervals such as a minute, it saves time and network resources to
>   track the cost values via a focused delegate Server rather than the
>   more general "root" Server.
>
>Is the idea just that you compartmentalize the fast-changing stuff from 
>the slow-changing stuff, so that your listing of what is changing 
>quickly only includes the things actually changing on that timescale, 
>so you don't end up also listing the calendar for the slowly-changing things in the same response?
>
[[SR]] yes, it is

>Also, nit: s/few/little/
>
[[SR]] done, thanks
>
>Is there a reason for "map" and "calendar" to be in different orders in 
>"filtered-cost-map-calendar" and "endpoint-cost-calendar-map"?
>
[[SR]]  There is no reason indeed. Resource name "endpoint-cost-calendar-map" has been turned into "endpoint-cost-map-calendar" throughout the document. 

>
>   o  the Calendar for "owdelay": is an array of 12 values each provided
>      on a time interval lasting 300 seconds (5 minutes).
>
>nit: s/owdelay/num-owdelay/
[[SR]] Done, thanks

>
>Sectgion 5
>
>I'd consider using a more recent Date in the example.
[[SR]] agree, done thanks
>
>Section 5.1.1
>
>   The input parameters of a "legacy" request for a filtered cost map,
>   defined by object ReqFilteredCostMap in section 11.3.2 of [RFC7285],
>   are augmented with one additional member.
>
>There's probably some pedantic consideration here about "other 
>extensions", such as the "multi-cost-types" member from RFC 8189.
[ [SR]   ] A sentence on RFC 8189 has been added as follows:
----- NEW 
The input parameters of a "legacy" request for a filtered cost map,
   defined by object ReqFilteredCostMap in section 11.3.2 of <xref target="RFC7285"/>,
   are augmented with one additional member. The same augmentation applies to object ReqFilteredCostMap
   defined in section 4.1.2 of <xref target="RFC8189"/>. ----- END

>
>   This field is an array of 1 to N boolean values, where N is the
>   number of requested metrics.  Each entry corresponds to the 
> requested
>
>Maybe reference RFC 8189 so the reader doesn't get confused by RFC 7285 
>specifying only a single metric type?
[ [SR]   ] The text was updated as follows:
----- NEW
This field is an array of 1 to N boolean values, where N is the
   number of requested metrics.  N is greater than 1 when the Client and
   the Server also implement [RFC8189]. ----- END
>
>Section 5.1.2
>
>   The non Calendar specific "meta" fields of a calendared Filtered Cost
>   Map response MUST include at least:
>     [...]
>
>side note: this structure where we effectively repeat the requirements 
>of all previous specifications is not going to scale well with future extensions.
[[SR]] Yes, special care on this aspect will be needed to moderate the data exchange volume. 

>
>   o  each "CalendarResponseAttributes" object in the array is specified
>      for one or more cost types for which the value of member
>      "calendared" is equal to 'true' and for which a Calendar is
>      provided for the requested information resource.
>
>Member 'calendared' of what data structure?
[[SR]] of data structure ReqFilteredCostMap. The text has been updated as follows:
----- NEW
each "CalendarResponseAttributes" object in the array is specified
      for one or more cost types for which the value of member
      "calendared", in object ReqFilteredCostMap provided in the Client request,
      is equal to 'true' and for which a Calendar is
      provided for the requested information resource. ----- END

>
>   o  "cost-type-names": is an array of one or more cost-type-names to
>      which the capabilities apply and for which a Calendar has been
>      requested.  The value of this member is a subset of the "cost-
>      type-names" array specified in the corresponding IRD Calendar
>      attributes.
>
>Just to check my understanding: in the IRD Calendar attributes, there's 
>a "calendar-attributes" member whose value is an array of objects, and 
>each of those objects has a "cost-type-names" member whose value is an 
>array of cost-type names.  So what we're saying here is that the 
>"cost-type-names" in a CalendarResponseAttributes entry are a subset of 
>the union of the "cost-type- names" members in all of the entries in 
>the "calendar-attributes" array of objects in the IRD calendar 
>attribute, which is not exactly what the quoted text seems to be saying.

[[SR]] The text, indeed is unclear. The text meant to says it is subset of the "cost-type-names" member of the entry in the "calendar-attributes" array of objects in the IRD that includes the requested cost type name.  To address this question and the next 2 ones, two updates have been made: 

1 - the text, in the last of the 3 preceding bullets presenting the "CalendarResponseAttributes" object was updated as follows. 
 
----- NEW  
the "CalendarResponseAttributes" object that applies to a cost
      type name has a corresponding "CalendarAttributes" object defined
      for this cost type name in the IRD capabilities of the requested
      information resource.  This object is the entry, in the "calendar-
      attributes" array member of the IRD resource entry, that includes
      the name of the requested cost type.  This corresponding
      "CalendarAttributes" object has the same values as object
      "CalendarResponseAttributes" for members "time-interval-size" and
      "number-of-intervals".  The members of the
      "CalendarResponseAttributes" object include all the members of the
      corresponding "CalendarAttributes" object.
----- END

2 - The text you quoted, that specifies member "cost-type-names" of object CalendarResponseAttributes has been updated as follows:
----- NEW
"cost-type-names": is an array of one or more cost-type-names to
      which the value of the other members of CalendarResponseAttributes
      apply and for which a Calendar has been requested.  The value of
      this member is a subset of the "cost-type-names" member of the
      abovementioned corresponding "CalendarAttributes" object in the
      "calendar-attributes" array member in the IRD. This member MUST
      be present when Cost Calendars are provided for more than one cost
      type. 
----- END
(last sentence addresses another review comment)

>
>   o  "time-interval-size": as specified in Section 4.1 and with the
>      same value.
>
>   o  "number-of-intervals": as specified in Section 4.1 and with the
>      same value.
>
>nit: "with the same value" could perhaps imply that there is a 
>requirement to have actually published an IRD calendar for this 
>resource and literally take the value from that existing calendar; 
>"with the same semantics" should relax that
>(perceived) requirement.

[[SR]] It is actually the same value, not only semantically. 
To clarify this, 3 updates have been made: 
1 - the abovementioned update "1"
2- the text on member "time-interval-size" has been updated as follows:
----- NEW
"time-interval-size": as specified in Section 4.1 and with the
      same value as in the abovementioned corresponding
      "CalendarAttributes" object.
----- END
3 - the text on member "time-interval-size" has been updated as follows:
----- NEW
"number-of-intervals ": as specified in Section 4.1 and with the
      same value as in the abovementioned corresponding
      "CalendarAttributes" object.
----- END
>
>Section 5.1.3
>
>   An example of non-real time information that can be provisioned in a
>   Calendar is the expected path throughput.  While the transmission
>
>nit: "non-real time" and "non-real-time" have different meanings, and I 
>think the latter is the intended one.
[[SR]] thanks, expression is now "non-real-time" 
>
>   usage patterns.  In this example, we assume that an ALTO Client
>   requests a Calendar of network provider defined throughput ratings,
>
>nit: hyphenate "network-provider-defined".
[[SR]] done, thanks
>
>     Content-Length: 1013
>     Content-Type: application/alto-costmap+json
>
>Please double-check the content length (for all the examples) -- it's a 
>bit annoying to do from the text rendering of the I-D that applies a 
>left indent, but assuming that the initial '{' is supposed to be the 
>first byte of the response body and the rest of the whitespace is part 
>of the response, I get something more like 1043 octets of content.
>
[[SR]] Thanks, the content length has been verified and updated for all the examples

>Section 5.2.1
>
>We should probably say that the interpretation of the various fields is 
>the same as the RFC 7285/8189 ReqEndpointCostMap, and "calendared" the 
>same as for ReqFilteredCostMap.
>
[[SR]] text was added as follows :
----- NEW
The interpretation of member "calendared" is the same as for the
   ReqFilteredCostMap object defined in Section 5.1.1 of this draft.
   The interpretation of the other member is the same as for object
   ReqEndpointCostMap is definedin [RFC7285] and [RFC8189].
----- END

>Section 5.2.3
>
>   o  C1 for Monday, Tuesday, Wednesday, Thursday, (weekdays)
>
>   o  C2 for Saturday, Sunday, (weekend)
>
>   - C3 for Friday (maintenance outage on July 4, 2014 from 02:00:00 GMT
>   to 04:00:00 GMT, or big holiday such as New Year evening).
>
>I'd consider using a more recent date than 2014 throughout this example.
>Also, nit: please use a consistent character to represent the bullet point.
>
[[SR]] Done, thanks year was changed to 2019 and bullets are harmonized

>  Host: alto.example.com
>
>Would it be more consistent with previous examples to use 
>custom.alto.example.com here (and in other examples)?
>
[[SR]] Done, thanks, host is now "custom.alto.example.com" everywhere

>
>Section 7
>
>
>   [RFC8446] specifies TLS 1.3 and writes in its section 1: "While TLS
>   1.3 is not directly compatible with previous versions, all versions
>   of TLS incorporate a versioning mechanism which allows Clients and
>   Servers to interoperably negotiate a common version if one is
>   supported by both peers".  ALTO Clients and Servers SHOULD support
>   both TLS 1.3 [RFC8446] and TLS 1.2 [RFC5246], and MAY support and use
>   newer versions of TLS as long as the negotiation process succeeds.
>
>I know this document has been in the works for a long time and so there 
>may be reluctance to make changes on this front, but I'll note that RFC
>8446 has been out for a year and half, so under normal conditions we'd 
>just say "use TLS 1.3 or newer" without mentioning 1.2.
>
>   participate in a DDoS attack.  The Calendar information would be
>   valuable information for when to persecute a DDoS attack.  A
>
>nit: "persecute" is an unusual word here; "execute" or "perform" seem 
>like better alternatives.
>
[[SR]] expression was changed to "perpetrate"

>   Hence, a more robust ALTO Client should adapt and extend protection
>   strategies specified in Section 15.2 of the base protocol.  For
>
>It's probably better to use the RFC number than just "the base protocol".
>
[[SR]]  Done, thanks
>Section 10.2
>
>I think [IEEE.754.2008] needs to be normative, as do RFCs 5246 and 
>8446, and draft-ietf-alto-incr-update-sse.
>
[[SR]] done thanks, these references are now normative
>
>