Session Initiation Protocol (SIP) Rate Control
draft-ietf-soc-overload-rate-control-10

[Ballot comment]
Thanks for producing this draft. It’s important.

I did have one question.

In this text, in 3.5.1. Default algorithm:

  TAU=4*T is a reasonable compromise between burst size and throttled
  rate adaptation at low offered rates.

will this always be true for SIP (so, “is”), or is there an appropriate qualifier that could be included?

[Ballot comment]
3.3 - Isn't the second paragraph completely redundant with the first? Why not remove it?

3.4 - What is the first sentence of the second paragraph trying to tell the implementer? That it can't lower the rate based on something other than overload state? That it has to do it "periodically", whatever that means? I don't get it.

  In other words, when multiple clients are being controlled by an
  overloaded server, at any given time some clients may receive
  requests at a rate below their target (maximum) SIP request rate
  while others above that target rate.

The *server* receives the request, not the client, right? I don't understand this sentence.

The second to last paragraph also seems redundant. Can it be removed?

3.5.1/3.5.2/3.5.3 - The language of "admitted/rejected" had me confused for a bit because it's talking about the client, which I think of as "sending/not-sending" requests; the server is the one doing the admitting (accepting) vs. rejecting. If SIP folks are used to this language, I guess it's fine, but it did take a reset when I first read it.

(1) What type of RFC is being requested (BCP, Proposed Standard, Internet Standard, Informational, Experimental, or Historic)? Why is this the proper type of RFC? Is this type of RFC indicated in the title page header?

- Proposed Standard

(2) The IESG approval announcement includes a Document Announcement Write-Up. Please provide such a Document Announcement Write-Up.

- Technical Summary:
The document defines a rate-based overload control mechanism for the Session Initiation Protocol (SIP) to prevent signaling overload. It uses the framework defined in the Session Initiation Protocol (SIP) Overload Control specification and adds the specifications needed for a rate-based control mechanism. With this specification, SIP entities can choose between the loss-based overload control defined in Session Initiation Protocol (SIP) Overload Control and the rate-based overload control defined in this specification.

- Working Group Summary:
The developement of this document resulted from a discussion in the WG on the overload feedback type (the pro's and con's of the feedback types discussed in Section 9. of RFC 6357). The WG decided to use loss-based control as the default mechanism in draft-ietf-soc-overload-control but allow extensions for other feedback types. Rate-based control was agreed as a needed extension as it has benefits in some scenarios. This draft provides the needed specifications for rate-based overload control. This draft was non-controversial and was is substantial interest in this specification. There was no competing proposal and it addresses the WG deliverable 'A specification for an SIP overload control mechanism based on implicit/explicit feedback'

- Document Quality:
The basic mechanisms defined in this specification have been implemented and evaluated in several simulators as part of the work of the SIPPING Overload Control Design Team. The results of these evaluations were presented in several SIPPING WG meetings. The document has been reviewed several times as it has been developed by several members of the SOC WG including Salvatore Loreto, Janet Gunn, Christer Holmberg, James Yu, Keith Drage and Vijay Gurbani.

- Personnel:
  Shepherd: Volker Hilt
  AD: Richard Barnes

(3) Briefly describe the review of this document that was performed by the Document Shepherd. If this version of the document is not ready for publication, please explain why the document is being forwarded to the IESG.

- The document was reviewed several times during its lifecycle by the shepherd. The document is ready for publication.

(4) Does the document Shepherd have any concerns about the depth or breadth of the reviews that have been performed?

-  No concerns on the reviews performed.

(5) Do portions of the document need review from a particular or from broader perspective, e.g., security, operational complexity, AAA, DNS, DHCP, XML, or internationalization? If so, describe the review that took place.

- No additional review needed.

(6) Describe any specific concerns or issues that the Document Shepherd has with this document that the Responsible Area Director and/or the IESG should be aware of? For example, perhaps he or she is uncomfortable with certain parts of the document, or has concerns whether there really is a need for it. In any event, if the WG has discussed those issues and has indicated that it still wishes to advance the document, detail those concerns here.

- No concerns.

(7) Has each author confirmed that any and all appropriate IPR disclosures required for full conformance with the provisions of BCP 78 and BCP 79 have already been filed. If not, explain why?

- Yes.

(8) Has an IPR disclosure been filed that references this document? If so, summarize any WG discussion and conclusion regarding the IPR disclosures.

- No.

(9) How solid is the WG consensus behind this document? Does it represent the strong concurrence of a few individuals, with others being silent, or does the WG as a whole understand and agree with it?

-  A significant number of WG members were involved in the discussion of the document over time and it can be expected that the majority of the WG understands and agrees with the document.

(10) Has anyone threatened an appeal or otherwise indicated extreme discontent? If so, please summarise the areas of conflict in separate email messages to the Responsible Area Director. (It should be in a separate email because this questionnaire is publicly available.)

- No

(11) Identify any ID nits the Document Shepherd has found in this document. (See http://www.ietf.org/tools/idnits/ and the Internet-Drafts Checklist). Boilerplate checks are not enough; this check needs to be thorough.

-  No nits.

(12) Describe how the document meets any required formal review criteria, such as the MIB Doctor, media type, and URI type reviews.

- Does not apply.

(13) Have all references within this document been identified as either normative or informative?

- Yes

(14) Are there normative references to documents that are not ready for advancement or are otherwise in an unclear state? If such normative references exist, what is the plan for their completion?

- No

(15) Are there downward normative references references (see RFC 3967)? If so, list these downward references to support the Area Director in the Last Call procedure.

- No

(16) Will publication of this document change the status of any existing RFCs? Are those RFCs listed on the title page header, listed in the abstract, and discussed in the introduction? If the RFCs are not listed in the Abstract and Introduction, explain why, and point to the part of the document where the relationship of this document to the other RFCs is discussed. If this information is not in the document, explain why the WG considers it unnecessary.

- No

(17) Describe the Document Shepherd's review of the IANA considerations section, especially with regard to its consistency with the body of the document. Confirm that all protocol extensions that the document makes are associated with the appropriate reservations in IANA registries. Confirm that any referenced IANA registries have been clearly identified. Confirm that newly created IANA registries include a detailed specification of the initial contents for the registry, that allocations procedures for future registrations are defined, and a reasonable name for the new registry has been suggested (see RFC 5226).

- All protocol extensions that the document makes are associated with the appropriate reservations in IANA registries and the IANA considerations section is clear.

(18) List any new IANA registries that require Expert Review for future allocations. Provide any public guidance that the IESG would find useful in selecting the IANA Experts for these new registries.

- No IANA registries are created.

(19) Describe reviews and automated checks performed by the Document Shepherd to validate sections of the document written in a formal language, such as XML code, BNF rules, MIB definitions, etc.

- Does not apply.

IESG/Authors/WG Chairs:

IANA has reviewed draft-ietf-soc-overload-rate-control-09 and has the following questions:

The IANA Considerations section says, in its entirety:

Header Field Parameter Name Predefined Values Reference
_______________________________________________________

Via          oc-algo          Yes            RFCABCD RFCOPRQ

However, Section 12 of the draft document draft-ietf-soc-overload-control-15 asks us to register the same Via header parameter (along with three others).

The IANA Considerations section doesn't specify whether this document is meant to register "oc-algo," or if it's only adding itself as a second reference.

If the IESG approves this document before it approves draft-ietf-soc-overload-control, can IANA use this document to register oc-algo?

If not, we'll have to keep it on hold in our queue until the IESG approves draft-ietf-soc-overload-control, at which point we'll make the registration via that document and then add a reference for this document.

Note:  The actions requested in this document will not be completed until the document has been approved for publication as an RFC. This message is only to confirm what actions will be performed.

The following Last Call announcement was sent out:

From: The IESG
To: IETF-Announce
CC:
Reply-To: ietf@ietf.org
Sender:
Subject: Last Call:  (Session Initiation Protocol (SIP) Rate Control) to Proposed Standard


The IESG has received a request from the SIP Overload Control WG (soc) to
consider the following document:
- 'Session Initiation Protocol (SIP) Rate Control'
  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
ietf@ietf.org mailing lists by 2014-08-22. Exceptionally, comments may be
sent to iesg@ietf.org instead. In either case, please retain the
beginning of the Subject line to allow automated sorting.

Abstract


  The prevalent use of Session Initiation Protocol (SIP) in Next
  Generation Networks necessitates that SIP networks provide adequate
  control mechanisms to maintain transaction throughput by preventing
  congestion collapse during traffic overloads. Already a loss-based
  solution to remedy known vulnerabilities of the SIP 503 (service
  unavailable) overload control mechanism has been proposed. This
  document proposes a rate-based control scheme to complement the
  loss-based control scheme, using the same signaling.




The file can be obtained via
http://datatracker.ietf.org/doc/draft-ietf-soc-overload-rate-control/

IESG discussion can be tracked via
http://datatracker.ietf.org/doc/draft-ietf-soc-overload-rate-control/ballot/


No IPR declarations have been submitted directly on this I-D.

(1) What type of RFC is being requested (BCP, Proposed Standard, Internet Standard, Informational, Experimental, or Historic)? Why is this the proper type of RFC? Is this type of RFC indicated in the title page header?

- Proposed Standard

(2) The IESG approval announcement includes a Document Announcement Write-Up. Please provide such a Document Announcement Write-Up.

- Technical Summary:
The document defines a rate-based overload control mechanism for the Session Initiation Protocol (SIP) to prevent signaling overload. It uses the framework defined in the Session Initiation Protocol (SIP) Overload Control specification and adds the specifications needed for a rate-based control mechanism. With this specification, SIP entities can choose between the loss-based overload control defined in Session Initiation Protocol (SIP) Overload Control and the rate-based overload control defined in this specification.

- Working Group Summary:
The developement of this document resulted from a discussion in the WG on the overload feedback type (the pro's and con's of the feedback types discussed in Section 9. of RFC 6357). The WG decided to use loss-based control as the default mechanism in draft-ietf-soc-overload-control but allow extensions for other feedback types. Rate-based control was agreed as a needed extension as it has benefits in some scenarios. This draft provides the needed specifications for rate-based overload control. This draft was non-controversial and was is substantial interest in this specification. There was no competing proposal and it addresses the WG deliverable 'A specification for an SIP overload control mechanism based on implicit/explicit feedback'

- Document Quality:
The basic mechanisms defined in this specification have been implemented and evaluated in several simulators as part of the work of the SIPPING Overload Control Design Team. The results of these evaluations were presented in several SIPPING WG meetings. The document has been reviewed several times as it has been developed by several members of the SOC WG including Salvatore Loreto, Janet Gunn, Christer Holmberg, James Yu, Keith Drage and Vijay Gurbani.

- Personnel:
  Shepherd: Volker Hilt
  AD: Richard Barnes

(3) Briefly describe the review of this document that was performed by the Document Shepherd. If this version of the document is not ready for publication, please explain why the document is being forwarded to the IESG.

- The document was reviewed several times during its lifecycle by the shepherd. The document is ready for publication.

(4) Does the document Shepherd have any concerns about the depth or breadth of the reviews that have been performed?

-  No concerns on the reviews performed.

(5) Do portions of the document need review from a particular or from broader perspective, e.g., security, operational complexity, AAA, DNS, DHCP, XML, or internationalization? If so, describe the review that took place.

- No additional review needed.

(6) Describe any specific concerns or issues that the Document Shepherd has with this document that the Responsible Area Director and/or the IESG should be aware of? For example, perhaps he or she is uncomfortable with certain parts of the document, or has concerns whether there really is a need for it. In any event, if the WG has discussed those issues and has indicated that it still wishes to advance the document, detail those concerns here.

- No concerns.

(7) Has each author confirmed that any and all appropriate IPR disclosures required for full conformance with the provisions of BCP 78 and BCP 79 have already been filed. If not, explain why?

- Yes.

(8) Has an IPR disclosure been filed that references this document? If so, summarize any WG discussion and conclusion regarding the IPR disclosures.

- No.

(9) How solid is the WG consensus behind this document? Does it represent the strong concurrence of a few individuals, with others being silent, or does the WG as a whole understand and agree with it?

-  A significant number of WG members were involved in the discussion of the document over time and it can be expected that the majority of the WG understands and agrees with the document.

(10) Has anyone threatened an appeal or otherwise indicated extreme discontent? If so, please summarise the areas of conflict in separate email messages to the Responsible Area Director. (It should be in a separate email because this questionnaire is publicly available.)

- No

(11) Identify any ID nits the Document Shepherd has found in this document. (See http://www.ietf.org/tools/idnits/ and the Internet-Drafts Checklist). Boilerplate checks are not enough; this check needs to be thorough.

-  ID nits show issues with references. Authors will fix this in the next version.

(12) Describe how the document meets any required formal review criteria, such as the MIB Doctor, media type, and URI type reviews.

- Does not apply.

(13) Have all references within this document been identified as either normative or informative?

- Yes

(14) Are there normative references to documents that are not ready for advancement or are otherwise in an unclear state? If such normative references exist, what is the plan for their completion?

- No

(15) Are there downward normative references references (see RFC 3967)? If so, list these downward references to support the Area Director in the Last Call procedure.

- One downref that will be fixed by authors in next version.

(16) Will publication of this document change the status of any existing RFCs? Are those RFCs listed on the title page header, listed in the abstract, and discussed in the introduction? If the RFCs are not listed in the Abstract and Introduction, explain why, and point to the part of the document where the relationship of this document to the other RFCs is discussed. If this information is not in the document, explain why the WG considers it unnecessary.

- No

(17) Describe the Document Shepherd's review of the IANA considerations section, especially with regard to its consistency with the body of the document. Confirm that all protocol extensions that the document makes are associated with the appropriate reservations in IANA registries. Confirm that any referenced IANA registries have been clearly identified. Confirm that newly created IANA registries include a detailed specification of the initial contents for the registry, that allocations procedures for future registrations are defined, and a reasonable name for the new registry has been suggested (see RFC 5226).

- All protocol extensions that the document makes are associated with the appropriate reservations in IANA registries and the IANA considerations section is clear.

(18) List any new IANA registries that require Expert Review for future allocations. Provide any public guidance that the IESG would find useful in selecting the IANA Experts for these new registries.

- No IANA registries are created.

(19) Describe reviews and automated checks performed by the Document Shepherd to validate sections of the document written in a formal language, such as XML code, BNF rules, MIB definitions, etc.

- Does not apply.