Port Control Protocol (PCP) Proxy Function
draft-ietf-pcp-proxy-09

[Ballot comment]
I share Stephen's curiosity in his Discuss, but I'll follow along there (I saw Med responded 15 minutes ago).

Thanks for addressing my Discuss, which was:

This should be an easy Discuss to resolve.

I was surprised to see

  In addition, this goes against the spirit of NAT gateways.  The main
  purpose of a NAT gateway is to make multiple downstream client
  devices making outgoing TCP connections to appear, from the point of
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  view of everything upstream of the NAT gateway, to be a single client
  device making outgoing TCP connections.  In the same spirit, it makes
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  sense for a PCP-capable NAT gateway to make multiple downstream
  client devices requesting port mappings to appear, from the point of
  view of everything upstream of the NAT gateway, to be a single client
  device requesting port mappings.
 
limited to TCP connections. Is this intentional? https://tools.ietf.org/html/rfc6887#section-2.2 certainly lists other transport protocols.

Is it correct to say

  In addition, this goes against the spirit of NAT gateways.  The main
  purpose of a NAT gateway is to make multiple downstream client
  devices to appear, from the point of
  view of everything upstream of the NAT gateway, to be a single client
  device. 
 
?

Please note that I'm not objecting to the focus on TCP in this text:

  Where this document uses the terms "upstream" and "downstream", the
  term "upstream" refers to the direction outbound packets travel
  towards the public Internet, and the term "downstream" refers to the
  direction inbound packets travel from the public Internet towards
  client systems.  Typically when a home user views a web site, their
  computer sends an outbound TCP SYN packet upstream towards the public
  Internet, and an inbound downstream TCP SYN ACK reply comes back from
  the public Internet.

[Ballot discuss]
This should be an easy Discuss to resolve.

I was surprised to see

  In addition, this goes against the spirit of NAT gateways.  The main
  purpose of a NAT gateway is to make multiple downstream client
  devices making outgoing TCP connections to appear, from the point of
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  view of everything upstream of the NAT gateway, to be a single client
  device making outgoing TCP connections.  In the same spirit, it makes
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  sense for a PCP-capable NAT gateway to make multiple downstream
  client devices requesting port mappings to appear, from the point of
  view of everything upstream of the NAT gateway, to be a single client
  device requesting port mappings.
 
limited to TCP connections. Is this intentional? https://tools.ietf.org/html/rfc6887#section-2.2 certainly lists other transport protocols.

Is it correct to say

  In addition, this goes against the spirit of NAT gateways.  The main
  purpose of a NAT gateway is to make multiple downstream client
  devices to appear, from the point of
  view of everything upstream of the NAT gateway, to be a single client
  device. 
 
?

Please note that I'm not objecting to the focus on TCP in this text:

  Where this document uses the terms "upstream" and "downstream", the
  term "upstream" refers to the direction outbound packets travel
  towards the public Internet, and the term "downstream" refers to the
  direction inbound packets travel from the public Internet towards
  client systems.  Typically when a home user views a web site, their
  computer sends an outbound TCP SYN packet upstream towards the public
  Internet, and an inbound downstream TCP SYN ACK reply comes back from
  the public Internet.

[Ballot discuss]

I have one thing I'd like to check. Maybe this just works fine,
but how does this function work with PCP authentication?  E.g.
in Figure 1, is the left-most client authenticating to the
middle or rightmost server? I think I could imagine either
answer being desirable and don't see a way that both could be
supported.

[Ballot comment]
I have these comments and questions:

1) There is no clear definition of what a PCP proxy really is. Section 1. shows it as a pure signalling entity only w/o any NAT functionality (no mapping functionality) but the document body itself talks about PCP proxies having a mapping table (and also the possibility of not -- Section 3.4.1). Adding such a statement about the PCP proxy is or can be to the intro or the terminology section is a good thing.

2) Section 3.1 talks about hairpinning:
There is a potential noteable issue in terms of network management: If the PCP proxy is performing the hair pinning for the Assigned External Address, the byte counters on the PCP server and the proxy will differ for the Assigned External Address. This might be worth to note in a network managment section (or elsewhere in the document).

[Ballot comment]
I have one comment:

There is no clear definition of what a PCP proxy really is. Section 1. shows it as a pure signalling entity only w/o any NAT functionality (no mapping functionality) but the document body itself talks about PCP proxies having a mapping table. Adding such a statement to the intro or the terminology section is a good thing.

(Via drafts-lastcall@iana.org): IESG/Authors/WG Chairs:

IANA has reviewed draft-ietf-pcp-proxy-08, which is currently in Last Call, and has the following comments:

We understand that, upon approval of this document, there are no IANA Actions that need completion.

While it is helpful for the IANA Considerations section of the document to remain in place upon publication, if the authors prefer to remove it, IANA doesn't object.

If this assessment is not accurate, please respond as soon as possible.

The following Last Call announcement was sent out:

From: The IESG
To: IETF-Announce
CC:
Reply-To: ietf@ietf.org
Sender:
Subject: Last Call:  (Port Control Protocol (PCP) Proxy Function) to Proposed Standard


The IESG has received a request from the Port Control Protocol WG (pcp)
to consider the following document:
- 'Port Control Protocol (PCP) Proxy Function'
  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 2015-06-29. 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


  This document specifies a new PCP functional element denoted as a PCP
  Proxy.  The PCP Proxy relays PCP requests received from PCP clients
  to upstream PCP server(s).  A typical deployment usage of this
  function is to help establish successful PCP communications for PCP
  clients that can not be configured with the address of a PCP server
  located more than one hop away.




The file can be obtained via
https://datatracker.ietf.org/doc/draft-ietf-pcp-proxy/

IESG discussion can be tracked via
https://datatracker.ietf.org/doc/draft-ietf-pcp-proxy/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, as indicated in the title page header.
    This is part of the PCP protocol suite, of which all docs are PS.

(2) The IESG approval announcement includes a Document Announcement Write-Up. Please provide such a Document Announcement Write-Up. Recent examples can be found in the "Action" announcements for approved documents. The approval announcement contains the following sections:

Technical Summary:

  This document specifies a new PCP functional element denoted as a PCP
  Proxy.  The PCP Proxy relays PCP requests received from PCP clients
  to upstream PCP server(s).  A typical deployment usage of this
  function is to help establish successful PCP communications for PCP
  clients that can not be configured with the address of a PCP server
  located more than one hop away.

Working Group Summary:

Was there anything in WG process that is worth noting? For example, was there controversy about particular points or were there decisions where the consensus was particularly rough?

    The WG has consensus on this document, nothing particularly rough.

Document Quality:

Are there existing implementations of the protocol? Have a significant number of vendors indicated their plan to implement the specification? Are there any reviewers that merit special mention as having done a thorough review, e.g., one that resulted in important changes or a conclusion that the document had no substantive issues?

    It is unknown whether there are existing implementations, although
    the existence of this draft was motivated by experience from Apple's
    implementation.

Personnel:

Who is the Document Shepherd?

    Dave Thaler

Who is the Responsible Area Director?

    Brian Haberman

(3) Briefly describe the review of this document that was performed by the Document Shepherd.

    1) reviewed it for technical quality
    2) verified that review was done during WGLC by multiple individuals
      plus the authors
    3) reviewed it against WGLC feedback, which was tracked by issue tracker
      tickets, to verify all were addressed
    4) checked id-nits

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

    No.

(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.

    None relevant.

(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.

    None.

(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.

    Yes.

(8) Has an IPR disclosure been filed that references this document?

    No IPR disclosures filed.

(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?

    It was discussed at length over a long period of time, by many in the WG.

(10) Has anyone threatened an appeal or otherwise indicated extreme discontent?

    No.

(11) Identify any ID nits the Document Shepherd has found in this document.

    None.

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

    None relevant.

(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?

    All normative references are to RFCs.

(15) Are there downward normative references references (see RFC 3967)?

    No.

(16) Will publication of this document change the status of any existing RFCs?

    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).

    This document makes no request of IANA.

(18) List any new IANA registries that require Expert Review for future allocations.

    None.

(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.

    None applicable.