Re: [Dime] Last Call: <draft-ietf-dime-agent-overload-08.txt> (Diameter Agent Overload and the Peer Overload Report) to Proposed Standard

[Steve Donovan <[e-mail]>]

Misha,

Thanks for the detailed review.

In the future this type of message only needs to go to the DIME mailing 
list.

I will deal with all of your comments in one email.

Regards,

Steve

On 1/17/17 12:23 PM, Misha Zaytsev wrote:
> Hi All,
>
> Here are my comments/questions to an agent overload draft.
> This the first part. Later on I will complete my review and send out 
> the second portion of the comments.
>
> 1. section 1 (editorial) removed "is" before "feasible".
>
> In the base specification, the goal is to handle abatement of the
>     overload occurrence as close to the source of the Diameter traffic as
>     feasible.
>
> "scenaios" -> "scenarios"
>
> The Peer overload report type is
>     defined in a generic fashion so that it can also be used for other
>     Diameter overload*scenarios*.
>
> 2. section 3.1.1 (editorial) replaced "were"-> "was"
>
> In both of these cases, the occurrence of overload in the single
>     agent must by handled by the client in a similar fashion as if the
>     client*was*  handling the overload of a directly connected server.
>
> 3. section 3.1.1 (question)
>
> An appropriate error response is sent back to the originator
>     of the request.
> Who sends "an appropriate" error response" in this case?
>
> 4. section 3.1.2 (editorial) changed "to"->"the"
>
> When the client has an active and a standby connection to the two
>     agents then an alternative strategy for responding to an overload
>     report from an agent is to change*the *standby connection to active and
>     route all traffic through the new active connection.
>
> 5. section 3.1.3 (editorial)
>
> An example of this type of deployment include*s*  when there are Diameter
>     agents between administrative domains.
> 6. section 3.1.3
>
> There is no section 2.2. I guess section 3.1.2 was meant here, right?
>
> Handling of overload of one or both of agents a11 or a12 in this case
>     is equivalent to that discussed in section 2.2.
>
> 7. section 3.2.1
>
> It is not clear which usage scenario is meant here.
>
>     It is envisioned that abatement algorithms will be defined that will
>     support the option for Diameter Endpoints to send peer reports.  For
>     instance, it is envisioned that one usage scenario for the rate
>     algorithm, [I-D.ietf-dime-doic-rate-control], which is being worked
>     on by the DIME working group as this document is being written, will
>     involve abatement being done on a hop-by-hop basis.
> 8. section 4
> Why is throttling to be applied and not diversion (like in case of 
> redundant agents)?
> In this scenario the reacting node should first handle the throttling of the
>     overloaded host or realm.
> "LOSS" Is it a new type defined in the scope of this draft?
> Note: The goal is to avoid traffic oscillations that might result
>        from throttling of messages for both the HOST/REALM overload
>        reports and the PEER overload reports.  This is especially a
>        concern if*both reports are of type LOSS*.
> 9. section 5.1.1
> Probably it is better to describe OC_PEER_REPORT feature in section 5.1?
> Otherwise, it is used as a well-known one while it is the first place 
> where it is mentioned.
> Also I think it is better to add more specific in this draft related 
> to peer report handling:
> - define Peer Report Reacting Node and Peer Report Reporting Node 
> terms explicitly and use them through the draft and especially 
> starting from section 5.1
> - add "Peer Report" prefix to all the described procedures
> Example: Capability Announcement -> Peer Report Capability Announcement
> 10. section 5.1.1/general
> "DiameterIdentity" and "Diameter identity"
> My proposal is to use one term through the spec.
> Under "DOIC node", an agent is meant here?
>   When an agent relays a request that includes a SourceID AVP in the
>     OC-Supported-Features AVP, a DOIC node that supports the
>     OC_PEER_REPORT feature MUST remove the received SourceID AVP and
>     replace it with a SourceID AVP containing its own Diameter identity.
> My proposal is to use peer report reacting node here re-phrasing this 
> statement below in the following way:
>   When relaying a request that includes a SourceID AVP in the
>     OC-Supported-Features AVP, a peer report reacting node MUST remove the received SourceID AVP and
>     replace it with a SourceID AVP containing its own DiameterIdentity.
> 11. section 5.1.2
> added the missed "to"
> changed "PEER_REPORT"-> "PEER"
> Note: The transaction state is used when the DOIC node is acting
>        as a peer-report reporting node and needs*to *send OC-OLR reports of
>        type*PEER *in answer messages.  The peer overload reports
>        are only included in answer messages being sent to peers that
>        support the OC_PEER_REPORT feature.
> "Diameter ID" term is not clarified anywhere.
> Re-phrased the appropriate statement a little bit, changed "Diameter 
> ID"->"value"
> Also there are other places in the draft where "Diameter ID" term is used.
> The peer supports the OC_PEER_REPORT feature if the received request
>     contains an OC-Supported-Features AVP with the OC-Feature-Vector with
>     the OC_PEER_REPORT feature bit set and with a SourceID AVP with a
>     value that matches the DiameterIdentity of the peer from which
>     the request was received.
> Agent is meant under "reporting node" here?
> Should not SourceID AVP not just stripped from the relayed answer, but 
> replaced with the SourceID AVP containing the DiameterIdentity of the 
> agent supporting OC_PEER_REPORT feature?
> When an agent relays an answer message, a reporting node that
>     supports the OC_PEER_REPORT feature MUST strip any SourceID AVP from
>     the OC-Supported-Features AVP.
> Hard to follow what was wanted to say here:
> Corrected the statement, but this is just my best guess.
> The OC-Peer-Algo AVP MUST indicate the overload abatement
>     algorithm that the reporting node wants the reacting nodes to use
>     *when *the reporting node send*s*  a peer overload report as a result of
>     becoming overloaded.
> Should not we add a separate if- statement for the case when the peer 
> does not support OC_PEER_REPORT feature when sending an answer message?
> 12. section 5.1.1 and 5.1.2
> Probably it is more helpful to illustrate OC_PEER_REPORT feature CA 
> using sequence diagrams like in the load info conveyance draft.
> 13. general.
> What about to use the writing for the same terms through the spec?
> Example1: "DOIC node" and "DOIC Node"
> Example2: "peer-report reporting node" and "peer report reporting node"
> 14. section 5.2.1.2, 5.2.2, 5.2.3 and general
> "peer-type OCS" and "peer report OCS" define the same term?
> Why not to use only one?
> Another example: "peer report" and "peer report-type" and "report of 
> type PEER"
> 15. section 5.2.3
> Probably it is better to re-phrase this statement a little bit + 
> corrected the misprints.
> If a*peer report*  reacting node receives an OC-OLR AVP of type peer and the
> SourceID matches the*DiameterIdentity *of the peer from which the*report*
> was received then the report was*generated *by the peer.
> Similar comment + corrected misprints for the next statement:
> If a peer report reacting node receives an OC-OLR AVP of type peer and the
> SourceID does not match the*DiameterIdentity *of the peer from which the
> *report *was received then the reacting node MUST ignore the overload
> report.
> Also I think it is useful to use one wording for the same term:
> "Peer Report OLR", "OC-OLR AVP", "OLR"
> Let's use a generic one "peer report"?
> Just minor comment: "the existing..." and "a new overload condition" 
> for all occurrences if my English is correct.
> 16. section 5.2.3
> How may it happen that peer report reacting node receives a peer 
> report not from the peer that generated it?
> Peer reports can be sent only to peer report reacting node, right? And 
> peer reports are not relayed, right?
> Best regards,
> /Misha
> 2017-01-09 17:35 GMT+03:00 The IESG <[e-mail] 
> <mailto:[e-mail]>>:
>
>     The IESG has received a request from the Diameter Maintenance and
>     Extensions WG (dime) to consider the following document: -
>     'Diameter Agent Overload and the Peer Overload Report'  
>     <draft-ietf-dime-agent-overload-08.txt> as Proposed Standard The
>     IESG plans to make a decision in the next few weeks, and solicits
>     final comments on this action. Please send substantive comments to
>     the [e-mail] <mailto:[e-mail]> mailing lists by
>     2017-01-23. Exceptionally, comments may be sent to [e-mail]
>     <mailto:[e-mail]> instead. In either case, please retain the
>     beginning of the Subject line to allow automated sorting. Abstract
>        This specification documents an extension to RFC 7683 (Diameter
>        Overload Indication Conveyance (DOIC)) base solution.  The
>     extension    defines the Peer overload report type.  The initial
>     use case for the    Peer report is the handling of occurrences of
>     overload of a Diameter    agent. Requirements The file can be
>     obtained via
>     https://datatracker.ietf.org/doc/draft-ietf-dime-agent-overload/
>     <https://datatracker.ietf.org/doc/draft-ietf-dime-agent-overload/>
>     IESG discussion can be tracked via
>     https://datatracker.ietf.org/doc/draft-ietf-dime-agent-overload/ballot/
>     <https://datatracker.ietf.org/doc/draft-ietf-dime-agent-overload/ballot/>
>     No IPR declarations have been submitted directly on this I-D. The
>     document contains these normative downward references. See RFC
>     3967 for additional information:    
>     draft-roach-dime-overload-ctrl: A Mechanism for Diameter Overload
>     Control (None - ) Note that some of these references may already
>     be listed in the acceptable Downref Registry.
>     _______________________________________________ DiME mailing list
>     [e-mail] <mailto:[e-mail]>
>     https://www.ietf.org/mailman/listinfo/dime
>     <https://www.ietf.org/mailman/listinfo/dime> 
>