Proxying Bound UDP in HTTP
draft-ietf-masque-connect-udp-listen-16

[Ballot comment]
I second Chris' comment about your Security Considerations. I almost stepped in to DISCUSS why you haven't said anything about amplification attack potential, but realized it's discussed in RFC 8656 (TURN) which you defer to, in its nearly 400 line long security considerations. I highly advise adding at least some basic description of the things an implementer should think about as their greatest risks. In my UDP 53 traumatized mind, this obviously would include amplification attacks.

[Ballot comment]
Thanks to Yaroslav R. for the SECDIR review and Alejandro S. for the shepherd's write up.

I will note that the security considerations continues in reference-after-reference and there could be some consideration on how to provide such extensive (and generally quite good) guidance without forcing readers to open 4+ RFCs to get it all.

[Ballot discuss]

# Éric Vyncke INT AD comments for draft-ietf-masque-connect-udp-listen-13
CC @evyncke

Thank you for the work put into this document.

Please find below some blocking DISCUSS points (easy to address), some non-blocking COMMENT points/nits (replies would be appreciated even if only for my own education).

Special thanks to Alejandro Sedeño for the shepherd's very short write-up but it lack information about the WG consensus, i.e., the IESG needs to trust the WG chairs.

I hope that this review helps to improve the document,

Regards,

-éric

Note: this ballot comments follow the Markdown syntax of https://github.com/mnot/ietf-comments/tree/main, i.e., they can be processed by a tool to create github issues.

## DISCUSS (blocking)

As noted in https://datatracker.ietf.org/doc/statement-iesg-handling-ballot-positions-20220121/, a DISCUSS ballot is a request to have a discussion on the points below; I really think that the document would be improved with a change here, but can be convinced otherwise.

### Section 2

Why not a MUST in `SHOULD use the 400 (Bad Request) status code` ? The MUST would ensure interoperability.

See also https://datatracker.ietf.org/doc/statement-iesg-statement-on-clarifying-the-use-of-bcp-14-key-words/

### Section 3 use of "IP"

s/target IP/target IP *address*/, using "IP" for "IP address" is an ellipsis that is ambiguous, therefore should not appear in a PS.

The above point occurs in other places in the document, please fix all of them even if most of the time "IP address" is used correctly in the document.

NB: I note that Gorry Fairhurst had the same comment.

### Section 10

Thanks for the MTU discussion, but what about plain ICMP messages handling ?

Even if handled by CONNECT-UDP, there should be some text in this section about ICMP handling, e.g., with a reference to CONNECT-UDP.

[Ballot comment]

## COMMENTS (non-blocking)


### Section 1

Please expand ICE at first use.

Why using capitalisation for Web in `two Web browsers` ?

s/This document describes an extension /This document *specifies* an extension / as it is PS.

To be honest, the text is not crystal clear.

### Section 7

s/The format of the String is defined using IP-literal, IPv4address, and port/The format of the String is defined using IP-literal *(for an IPv6 address)*, IPv4address, and port/ ? I would save a heart attack for some IPv6 fanatics ;-)

### Section 9

Expand TURN at first use ?

As a side note, I appreciate the use of "MUST" rather than "SHOULD" in this section.

### Appendix B

The discussion about CONNECT-IP would benefit from moving to the section 1.

[Ballot comment]
Section 3:

246 >    If the uncompressed Context ID is closed, the proxy MUST NOT open new
247 >    compressed Context IDs.  Allowing the proxy to do so would permit
248 >    traffic from source tuples not selected by the client, defeating the
249 >    IP restriction described in Section 8.1.  Note that compressed
250 >    Context IDs that were established prior to the closing of the
251 >    uncompressed Context ID are not impacted.

This resolves half of Ines's question 3 (pre-existing compressed contexts
survive), but leaves the other half open: is the client also expected to
stop opening *new* compressed Context IDs once it has closed its uncompressed
one, or is the restriction deliberately one-sided because the client is
trusted to only register targets it still wants to hear from? Section 8.1
reads as though the asymmetry is intentional -- the client is the one doing
the restricting -- but the document never says so, and a reader coming from
the proxy-side MUST just above could reasonably wonder whether the same
prohibition was meant to apply symmetrically. A one-sentence clarification
would help here.

---

Section 9:

490 >    Note that if the compression response (COMPRESSION_ACK or
491 >    COMPRESSION_CLOSE) cannot be immediately sent due to flow or
492 >    congestion control, an upper limit on how many compression responses
493 >    the endpoint is willing to buffer MUST be set to prevent memory
494 >    exhaustion.  The proxy MUST abort the request stream if this limit is
495 >    reached.

Aborting the whole request stream -- tearing down every Context ID on the
tunnel -- seems like a heavy-handed response to a buffering limit on
COMPRESSION_ACK/COMPRESSION_CLOSE alone, especially since ordinary UDP
payload congestion elsewhere in the tunnel isn't given the same treatment.
Have the authors considered whether rejecting or dropping the specific
registration that would overflow the buffer (i.e., failing that one
COMPRESSION_ASSIGN) is sufficient, reserving the full abort for cases where
the endpoint can no longer track state safely at all?

[Ballot comment]
Hi David and Abhijit,

Thank you for the effort put into this well-written document.

Thanks also to Aihua Guo for the OPSDIR review.

Please find below some few comments:

# I failed to find where “unextended UDP proxying request“ was defined. Idem for “bound UDP proxying”.

# valid target

CURRENT:
  When "target_host" and "target_port" are set to a valid target,

I guess we meant here valid host and port values? If so, please make that explicit as I wasn’t sure if by “valid target” we imply some other checks.

# wildcars

CURRENT:
  If only one of the "target_host" and the "target_port" variables is
  set to the '*' character, the request is malformed. 

Maybe this is obvious for the authors, but it wasn’t clear to be why having both as wildcard is acceptable but, for example, expressing no port preference is not allowed.

# Like any address sharing mechanism, the operational complications in rfc6269 will be experienced. I suggest to a note under Section 10.

# Likewise, operating a proxy will have to consider the Logging requirements similar to rfc6888#section-4 are required. You may consider a brief note under Section 10.

# I sent a PR with few editorial change proposals [1].

Cheers,
Med

[1] https://github.com/ietf-wg-masque/draft-ietf-masque-connect-udp-listen/pull/52/changes

[Ballot comment]
I have some COMMENTS (non-blocking), which I hope will improve this specification:

(1) Perhaps editorial, but at least reducing clarity for me: the terms "IP" "target IP" "unknown IPs" "Restricting IPs" "Unknown IP" etc seem like an incorrect use of an abbreviation IP meaning the "Internet Protocol". Please check carefully and then replace "IP" by "IP address" or "IP addresses" etc, to follow the usage in https://www.rfc-editor.org/info/rfc9484/.

(2) The text says: “Once an endpoint has either sent or received a COMPRESSION_CLOSE for a given Context ID, it MUST NOT send any further datagrams with that Context ID. "
- This was understood, but I did not see where the document said whether datagrams could be re-ordered - so, can datagrams be delivered after a close? .. and what should then happen? (Is it intended to be covered by section 8?)

(3) (Memory) limits are appropriately identified in section 9, but  no method is defined to detect these limits being exceeded. Ought this section also to recommend/require logging or counting when these limits are exceeded?

I also note these NiTs:
The text says: "If an endpoint nreceives COMPRESSION_ACK capsule for a Context ID "
- Insert “a” before “COMPRESSION_ACK capsule”?
The text says: "the effective MTU will change.” I expect this is /change/reduce/ - since I would not expect it to increase by adding protocol headers!

Request for IETF Last Call review by ARTART Completed: Ready with Nits. Reviewer: Jasdip Singh. Sent review to list. Submission of review completed at an earlier date.

IESG/Authors/WG Chairs:

IANA has completed its review of draft-ietf-masque-connect-udp-listen-12. If any part of this review is inaccurate, please let us know.

IANA understands that, upon approval of this document, there are two actions that we must complete.

First, in the Hypertext Transfer Protocol (HTTP) Field Name Registry located at:

https://www.iana.org/assignments/http-fields/

two new registrations are to be made as follows:

Field Name: Connect-UDP-Bind
Status: permanent
Structured Type: Item
Reference: [ RFC-to-be ]
Comments:

Field Name: Proxy-Public-Address
Status: permanent
Structured Type: List
Reference: [ RFC-to-be ]
Comments:

As this document requests registrations in an Expert Review or Specification Required (see RFC 8126) registry, we have initiated the required Expert Review via a separate request. This review must be completed before the document's IANA state can be changed to "IANA OK."

Second, in the HTTP Capsule Types registry in the Multiplexed Application Substrate over QUIC Encryption (MASQUE) registry group located at:

https://www.iana.org/assignments/masque/

the following three provisional registrations will be changed to permanent and their references changed to [ RFC-to-be ]:

Value: 0x11
Capsule Type: COMPRESSION_ASSIGN
Status: permanent
Reference: [ RFC-to-be ]
Date: [ TBD-at-registration ]
Change Controller: IETF
Contact: [MASQUE_WG]

Value: 0x12
Capsule Type: COMPRESSION_ACK
Status: permanent
Reference: [ RFC-to-be ]
Date: [ TBD-at-registration ]
Change Controller: IETF
Contact: [MASQUE_WG]

Value: 0x13
Capsule Type: COMPRESSION_CLOSE
Status: permanent
Reference: [ RFC-to-be ]
Date: [ TBD-at-registration ]
Change Controller: IETF
Contact: [MASQUE_WG]

We understand that these are the only actions required to be completed upon approval of 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 meant only to confirm the list of actions that will be performed.

For definitions of IANA review states, please see:

https://datatracker.ietf.org/help/state/draft/iana-review

Thank you,

David Dong
IANA Services Sr. Specialist

The following Last Call announcement was sent out (ends 2026-06-23):

From: The IESG
To: IETF-Announce
CC: asedeno@google.com, draft-ietf-masque-connect-udp-listen@ietf.org, martenseemann@gmail.com, masque-chairs@ietf.org, masque@ietf.org, mbishop@evequefou.be
Reply-To: last-call@ietf.org
Sender:
Subject: Last Call:  (Proxying Bound UDP in HTTP) to Proposed Standard


The IESG has received a request from the Multiplexed Application Substrate
over QUIC Encryption WG (masque) to consider the following document: -
'Proxying Bound UDP in HTTP'
  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
last-call@ietf.org mailing lists by 2026-06-23. 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 mechanism to proxy UDP in HTTP only allows each UDP proxying
  request to transmit to a specific host and port.  This is well suited
  for UDP client-server protocols such as HTTP/3, but is not sufficient
  for some UDP peer-to-peer protocols like WebRTC.  This document
  defines an extension to UDP proxying in HTTP that enables such use-
  cases.




The file can be obtained via
https://datatracker.ietf.org/doc/draft-ietf-masque-connect-udp-listen/



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

# Document Shepherd Write-Up for Group Documents

*This version is dated 4 July 2022.*

Thank you for your service as a document shepherd. Among the responsibilities is
answering the questions in this write-up to give helpful context to Last Call
and Internet Engineering Steering Group ([IESG][1]) reviewers, and your
diligence in completing it is appreciated. The full role of the shepherd is
further described in [RFC 4858][2]. You will need the cooperation of the authors
and editors to complete these checks.

Note that some numbered items contain multiple related questions; please be sure
to answer all of them.

## Document History

1. Does the working group (WG) consensus represent the strong concurrence of a
  few individuals, with others being silent, or did it reach broad agreement?

This draft seemed like a logical extension to connect-udp and reached broad WG
consensus.

2. Was there controversy about particular points, or were there decisions where
  the consensus was particularly rough?

No.

3. Has anyone threatened an appeal or otherwise indicated extreme discontent? If
  so, please summarize 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.

4. For protocol documents, are there existing implementations of the contents of
  the document? Have a significant number of potential implementers indicated
  plans to implement? Are any existing implementations reported somewhere,
  either in the document itself (as [RFC 7942][3] recommends) or elsewhere
  (where)?

There are two existing independent interoperable implementations. One in Google
QUICHE, and one in quic-go.

## Additional Reviews

5. Do the contents of this document closely interact with technologies in other
  IETF working groups or external organizations, and would it therefore benefit
  from their review? Have those reviews occurred? If yes, describe which
  reviews took place.

No.

6. Describe how the document meets any required formal expert review criteria,
  such as the MIB Doctor, YANG Doctor, media type, and URI type reviews.

N/A.

7. If the document contains a YANG module, has the final version of the module
  been checked with any of the [recommended validation tools][4] for syntax and
  formatting validation? If there are any resulting errors or warnings, what is
  the justification for not fixing them at this time? Does the YANG module
  comply with the Network Management Datastore Architecture (NMDA) as specified
  in [RFC 8342][5]?

N/A.

8. Describe reviews and automated checks performed to validate sections of the
  final version of the document written in a formal language, such as XML code,
  BNF rules, MIB definitions, CBOR's CDDL, etc.

## Document Shepherd Checks

9. Based on the shepherd's review of the document, is it their opinion that this
  document is needed, clearly written, complete, correctly designed, and ready
  to be handed off to the responsible Area Director?

Yes.

10. Several IETF Areas have assembled [lists of common issues that their
    reviewers encounter][6]. For which areas have such issues been identified
    and addressed? For which does this still need to happen in subsequent
    reviews?

This document was reviewed by HTTPDIR, which resulted in a Ready w/nits state.
The nits have been addressed in -11.

11. What type of RFC publication is being requested on the IETF stream ([Best
    Current Practice][12], [Proposed Standard, Internet Standard][13],
    [Informational, Experimental or Historic][14])? Why is this the proper type
    of RFC? Do all Datatracker state attributes correctly reflect this intent?

Proposed Standard. This matches other MASQUE documents.

12. Have reasonable efforts been made to remind all authors of the intellectual
    property rights (IPR) disclosure obligations described in [BCP 79][7]? To
    the best of your knowledge, have all required disclosures been filed? If
    not, explain why. If yes, summarize any relevant discussion, including links
    to publicly-available messages when applicable.

The authors have confirmed that they are not aware of any IPR.

13. Has each author, editor, and contributor shown their willingness to be
    listed as such? If the total number of authors and editors on the front page
    is greater than five, please provide a justification.

Yes.

14. Document any remaining I-D nits in this document. Simply running the [idnits
    tool][8] is not enough; please review the ["Content Guidelines" on
    authors.ietf.org][15]. (Also note that the current idnits tool generates
    some incorrect warnings; a rewrite is underway.)

Done.

15. Should any informative references be normative or vice-versa? See the [IESG
    Statement on Normative and Informative References][16].

No.

16. List any normative references that are not freely available to anyone. Did
    the community have sufficient access to review any such normative
    references?

No.

17. Are there any normative downward references (see [RFC 3967][9] and [BCP
    97][10]) that are not already listed in the [DOWNREF registry][17]? If so,
    list them.

No.

18. Are there normative references to documents that are not ready to be
    submitted to the IESG for publication or are otherwise in an unclear state?
    If so, what is the plan for their completion?

No.

19. Will publication of this document change the status of any existing RFCs? If
    so, does the Datatracker metadata correctly reflect this and are those RFCs
    listed on the title page, in the abstract, and discussed in the
    introduction? If not, explain why and point to the part of the document
    where the relationship of this document to these other RFCs is discussed.

No.

20. 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 aspects of the document requiring IANA assignments are
    associated with the appropriate reservations in IANA registries. Confirm
    that any referenced IANA registries have been clearly identified. Confirm
    that each newly created IANA registry specifies its initial contents,
    allocations procedures, and a reasonable name (see [RFC 8126][11]).

Confirmed.

HTTP Fields -- new values are not yet in the registry; this is expected.
Capsules -- new values are present (provisional) in the registry.

21. List any new IANA registries that require Designated Expert Review for
    future allocations. Are the instructions to the Designated Expert clear?
    Please include suggestions of designated experts, if appropriate.

None.

[1]: https://www.ietf.org/about/groups/iesg/
[2]: https://www.rfc-editor.org/rfc/rfc4858.html
[3]: https://www.rfc-editor.org/rfc/rfc7942.html
[4]: https://wiki.ietf.org/group/ops/yang-review-tools
[5]: https://www.rfc-editor.org/rfc/rfc8342.html
[6]: https://wiki.ietf.org/group/iesg/ExpertTopics
[7]: https://www.rfc-editor.org/info/bcp79
[8]: https://www.ietf.org/tools/idnits/
[9]: https://www.rfc-editor.org/rfc/rfc3967.html
[10]: https://www.rfc-editor.org/info/bcp97
[11]: https://www.rfc-editor.org/rfc/rfc8126.html
[12]: https://www.rfc-editor.org/rfc/rfc2026.html#section-5
[13]: https://www.rfc-editor.org/rfc/rfc2026.html#section-4.1
[14]: https://www.rfc-editor.org/rfc/rfc2026.html#section-4.2
[15]: https://authors.ietf.org/en/content-guidelines-overview
[16]: https://www.ietf.org/about/groups/iesg/statements/normative-informative-references/
[17]: https://datatracker.ietf.org/doc/downref/

# Document Shepherd Write-Up for Group Documents

*This version is dated 4 July 2022.*

Thank you for your service as a document shepherd. Among the responsibilities is
answering the questions in this write-up to give helpful context to Last Call
and Internet Engineering Steering Group ([IESG][1]) reviewers, and your
diligence in completing it is appreciated. The full role of the shepherd is
further described in [RFC 4858][2]. You will need the cooperation of the authors
and editors to complete these checks.

Note that some numbered items contain multiple related questions; please be sure
to answer all of them.

## Document History

1. Does the working group (WG) consensus represent the strong concurrence of a
  few individuals, with others being silent, or did it reach broad agreement?

This draft seemed like a logical extension to connect-udp and reached broad WG
consensus.

2. Was there controversy about particular points, or were there decisions where
  the consensus was particularly rough?

No.

3. Has anyone threatened an appeal or otherwise indicated extreme discontent? If
  so, please summarize 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.

4. For protocol documents, are there existing implementations of the contents of
  the document? Have a significant number of potential implementers indicated
  plans to implement? Are any existing implementations reported somewhere,
  either in the document itself (as [RFC 7942][3] recommends) or elsewhere
  (where)?

There are two existing independent interoperable implementations. One in Google
QUICHE, and one in quic-go.

## Additional Reviews

5. Do the contents of this document closely interact with technologies in other
  IETF working groups or external organizations, and would it therefore benefit
  from their review? Have those reviews occurred? If yes, describe which
  reviews took place.

No.

6. Describe how the document meets any required formal expert review criteria,
  such as the MIB Doctor, YANG Doctor, media type, and URI type reviews.

N/A.

7. If the document contains a YANG module, has the final version of the module
  been checked with any of the [recommended validation tools][4] for syntax and
  formatting validation? If there are any resulting errors or warnings, what is
  the justification for not fixing them at this time? Does the YANG module
  comply with the Network Management Datastore Architecture (NMDA) as specified
  in [RFC 8342][5]?

N/A.

8. Describe reviews and automated checks performed to validate sections of the
  final version of the document written in a formal language, such as XML code,
  BNF rules, MIB definitions, CBOR's CDDL, etc.

## Document Shepherd Checks

9. Based on the shepherd's review of the document, is it their opinion that this
  document is needed, clearly written, complete, correctly designed, and ready
  to be handed off to the responsible Area Director?

Yes.

10. Several IETF Areas have assembled [lists of common issues that their
    reviewers encounter][6]. For which areas have such issues been identified
    and addressed? For which does this still need to happen in subsequent
    reviews?

This document was reviewed by HTTPDIR, which resulted in a Ready w/nits state.
The nits have been addressed in -11.

11. What type of RFC publication is being requested on the IETF stream ([Best
    Current Practice][12], [Proposed Standard, Internet Standard][13],
    [Informational, Experimental or Historic][14])? Why is this the proper type
    of RFC? Do all Datatracker state attributes correctly reflect this intent?

Proposed Standard. This matches other MASQUE documents.

12. Have reasonable efforts been made to remind all authors of the intellectual
    property rights (IPR) disclosure obligations described in [BCP 79][7]? To
    the best of your knowledge, have all required disclosures been filed? If
    not, explain why. If yes, summarize any relevant discussion, including links
    to publicly-available messages when applicable.

The authors have confirmed that they are not aware of any IPR.

13. Has each author, editor, and contributor shown their willingness to be
    listed as such? If the total number of authors and editors on the front page
    is greater than five, please provide a justification.

Yes.

14. Document any remaining I-D nits in this document. Simply running the [idnits
    tool][8] is not enough; please review the ["Content Guidelines" on
    authors.ietf.org][15]. (Also note that the current idnits tool generates
    some incorrect warnings; a rewrite is underway.)

Done.

15. Should any informative references be normative or vice-versa? See the [IESG
    Statement on Normative and Informative References][16].

No.

16. List any normative references that are not freely available to anyone. Did
    the community have sufficient access to review any such normative
    references?

No.

17. Are there any normative downward references (see [RFC 3967][9] and [BCP
    97][10]) that are not already listed in the [DOWNREF registry][17]? If so,
    list them.

No.

18. Are there normative references to documents that are not ready to be
    submitted to the IESG for publication or are otherwise in an unclear state?
    If so, what is the plan for their completion?

No.

19. Will publication of this document change the status of any existing RFCs? If
    so, does the Datatracker metadata correctly reflect this and are those RFCs
    listed on the title page, in the abstract, and discussed in the
    introduction? If not, explain why and point to the part of the document
    where the relationship of this document to these other RFCs is discussed.

No.

20. 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 aspects of the document requiring IANA assignments are
    associated with the appropriate reservations in IANA registries. Confirm
    that any referenced IANA registries have been clearly identified. Confirm
    that each newly created IANA registry specifies its initial contents,
    allocations procedures, and a reasonable name (see [RFC 8126][11]).

Confirmed.

HTTP Fields -- new values are not yet in the registry; this is expected.
Capsules -- new values are present (provisional) in the registry.

21. List any new IANA registries that require Designated Expert Review for
    future allocations. Are the instructions to the Designated Expert clear?
    Please include suggestions of designated experts, if appropriate.

None.

[1]: https://www.ietf.org/about/groups/iesg/
[2]: https://www.rfc-editor.org/rfc/rfc4858.html
[3]: https://www.rfc-editor.org/rfc/rfc7942.html
[4]: https://wiki.ietf.org/group/ops/yang-review-tools
[5]: https://www.rfc-editor.org/rfc/rfc8342.html
[6]: https://wiki.ietf.org/group/iesg/ExpertTopics
[7]: https://www.rfc-editor.org/info/bcp79
[8]: https://www.ietf.org/tools/idnits/
[9]: https://www.rfc-editor.org/rfc/rfc3967.html
[10]: https://www.rfc-editor.org/info/bcp97
[11]: https://www.rfc-editor.org/rfc/rfc8126.html
[12]: https://www.rfc-editor.org/rfc/rfc2026.html#section-5
[13]: https://www.rfc-editor.org/rfc/rfc2026.html#section-4.1
[14]: https://www.rfc-editor.org/rfc/rfc2026.html#section-4.2
[15]: https://authors.ietf.org/en/content-guidelines-overview
[16]: https://www.ietf.org/about/groups/iesg/statements/normative-informative-references/
[17]: https://datatracker.ietf.org/doc/downref/