Diameter Credit-Control Application
draft-ietf-dime-rfc4006bis-12

[Ballot comment]
Thanks for addressing my DISCUSS point.

Section 8.65

Any reason you are allowing encoding an IPv4 address as a IPv4-Mapped IPv6 Address while you can directly use address family 1 to encode it directly as an IPv4 address? This allows for two different encodings for the same address.

[Ballot comment]
Thank you for addressing my DISCUSS points.  Original ballot comments preserved below:

Some additional significant but not necessarily DISCUSS-worthy
comments, followed by more editorial- and nit-level things.

In Section 1.3, "Advertising Application Support" uses the same
Auth-Application-ID value as for RFC 4006; what are the interop
consequences of this?

Alissa already noted that the text about how to split (sub-)AVPs
between the foo and foo-Extension AVPs is inconsistent among them --
e.g., Redirect-Server-Extension and User-Equipment-Info say "SHOULD
send [in the old one]", but Subscription-Id-Extension has separate
text about "[i]f full backward compatibility with [RFC4006] is
required" and slightly different behavior described.  We should try
to catch all instances of this sort of backwards compatibility and
make them consistent.

The use of UTF8String for URLs and URIs (e.g., Redirect-Address-URL)
might benefit from additional text about the expected contents.  A
lot of the time when we use a UTF8 container for names (whether
domain names or other kinds), we specify what normalization form and
canonicalization are performed, whether domain names are A-labels or
U-labels, etc., as there's a lot of potential flexibility not all of
which is good.  In this case, since the communication is only
between trusted actors, perhaps the additional restrictions are not
needed, but I am curious if the topic was raised in the WG.

Thank you for adding the Privacy Considerations and list of
Privacy-Sensitive AVPs!

Section 14

  [...] The Diameter credit-
  control application is often used within one domain, and there may be
  a single hop between the peers.  In these environments, the use of
  TLS/TCP, DTLS/SCTP or IPsec is sufficient.

I did not see any concrete guidance on what would suffice in other
environments (with multiple hops between peers).  Is this the realm
of the mythical "end-to-end security mechanism" for Diameter that is
much-desired?  (The last paragraph does have guidance on what might
*not* suffice, which is not exactly the same thing.)

  Even without any modification to the messages, an adversary can
  eavesdrop on transactions that contain privacy-sensitive information
  about the user.

This ("an adversary can") makes it sounds as if there is no
confidentiality protection anywhere in the system, but that's what
TLS/DTLS/IPSec are supposed to provide.  So maybe "an adversary that
can eavesdrop on transactions can obtain privacy-sensitive
information [...]" is better.

(Editorial- and nit-level stuff follows.)

Section 4

  A flexible credit-control application specific failure handling is
  defined in which the home service provider can model the credit-
  control client behavior according to its own credit risk management
  policy.

This sentence is hard to parse -- in "credit-control application
specific" what does "specific" bind to?  What is being modelled?  Is
anything being controlled (as opposed to modelled)?

Section 4.1.1

  2.  The Service-Parameter-Info AVP MAY be used as a container to pass
  legacy rating information in its original encoded form (e.g., ASN.1
  BER).  [...]

Why BER and not DER?  The unnecessary flexibility in BER vs. DER has
been known to tickle parser bugs and create security
vulnerabilities.

Section 4.1.2

  [...] To
  facilitate interoperability, it is RECOMMENDED that the rating input
  and the values of the Service-Context-Id be coordinated via an
  informational RFC or other permanent and readily available reference.
  The specification of another cooperative standardization body (e.g.,
  3GPP, OMA, or 3GPP2) SHOULD be used.

The RECOMMENDED and SHOULD seem slightly in conflict.

Section 5.1.1

As noted elsewhere, 60 seconds per minute does not always hold; it
seems that this text could be reworded to just talk about a
"constant rate" or "constant level per fixed time period" or
similar.

Section 5.1.2

  [...]
  timer (Section 13) every time a CCR message with the value
  UPDATE_REQUEST is sent while they are in PendingU state.  When
  answers to all pending messages are received, the state machine moves
  to OPEN state, and Tx is stopped.

Transmission, or the Tx timer (is stopped)?

Using a different title for Section 5.2.2 might make the parallel
between it and Section 5.2.1 more clear.  That is, perhaps something
like "First Interrogation Included with Authorization Messages".

Section 5.7

  [...] It is RECOMMENDED that the client complement the credit-
  control failure procedures with backup accounting flow toward an
  accounting server. [...]

Nit: it looks like there's a missing article here, maybe "a backup
accounting flow" is better.

  The AAA transport profile [RFC3539] defines the application layer
  watchdog algorithm that enables failover from a peer that has failed
  and is controlled by a watchdog timer (Tw) defined in [RFC3539].

Nit: Is it "the" watchdog algorithm or "an" watchdog algorithm?

Section 6.2

Should there be text indicating how the client indicates what
service the balance check is being requested for?

Section 8.54

Maybe give a section reference in RFC 3580 for how the formatting is
done?

Section 12

  [...] Initially, such Expert discussions take place on the AAA
  WG mailing list.

That list appears to be dead, suggesting that this text should be
updated.  (I also agree with Adam's comments about updating the IANA Considerations.)

Why is the disclaimer in Section B.4 (and other examples) not needed in Section B.3?

[Ballot comment]
Thanks for addressing my DISCUSS.

Original COMMENT:

= Section 1 =

(1) I know it's a term of art, but the term "next generation wireless networks" seems a bit out of place in two ways: (1) "wireless" seems more generic than what is implied (i.e., "cellular," I assume), and (2) is Rel-13 considered "next generation" still?

(2) "Diameter base protocol" should cite RFC 6733.

= Section 5.1 =

Assuming G-S-U stands for granted service unit, the acronym should be given upon first use here.

= Section 8.52 =

(1) Why do you need to specify the ability to send either the IMEISV or the IMEI?


(2)
"If the type of the equipment is one of the
  enumerated types of User-Equipment-Info-Type AVP, then the credit-
  control client SHOULD send the information in the User-Equipment-Info
  AVP, in addition to or instead of the User-Equipment-Info-Extension
  AVP."

Why is this normative recommendation in support of backwards compatibility different from the one given for the Subscription-Id-Extension AVP in Sec. 8.58?

= Section 15.1 =

"Redirect-Server-Address AVP: the service-provider may embed
        personal information on the subscriber in the URL/I (e.g. to
        create a personalized message)."
   
This seems like a bad idea that, if it's going to be mentioned, should be recommended against.

[Ballot comment]
I only scanned the document, so I only have one minor question/comment:

In Section 8.39: Redirect-Server-Address looks underspecified to me. It says "address". Is it a well known DIAMETER term? What is the syntax of address? Is it a URI or something else?

[Ballot comment]
Rich version of this review at:
https://mozphab-ietf.devsvcdev.mozaws.net/D3353


I only gave this a light read. Some minor comments below.

COMMENTS
S 1.2.
>        deduction of credit from the end user account when service is
>        completed and refunding of reserved credit that is not used.
> 
>      Diameter Credit-control Server  A Diameter credit-control server acts
>        as a prepaid server, performing real-time rating and credit-
>        control.  It is located in the home domain and is accessed by

a definition of "home domain" would be useful


S 2.
>      credit-control application.
> 
>      When an end user requests services such as SIP or messaging, the
>      request is typically forwarded to a service element (e.g., SIP Proxy)
>      in the user's home domain.  In some cases it might be possible that
>      the service element in the visited domain can offer services to the

also define visited domain, or at least point to a reference.


S 3.1.
>                                  [ CC-Correlation-Id ]
>                                  [ User-Equipment-Info ]
>                                  [ User-Equipment-Info-Extension ]
>                                  *[ Proxy-Info ]
>                                  *[ Route-Record ]
>                                  *[ AVP ]

Please expand AVP on first use.


S 4.
>      control client requests credit authorization from the credit-control
>      server prior to allowing any service to be delivered to the end user.
> 
>      In the first model, the credit-control server rates the request,
>      reserves a suitable amount of money from the user's account, and
>      returns the corresponding amount of credit resources.  Note that

Sorry, reserves the balance or the amount reserved?


S 14.
> 
>      Even without any modification to the messages, an adversary can
>      eavesdrop on transactions that contain privacy-sensitive information
>      about the user.  Also, by monitoring the credit-control messages one
>      can collect information about the credit-control server's billing
>      models and business relationships.

I'm having trouble reading these two paragraphs. Are they about what
happens if TLS isn't used?

[Ballot discuss]
Section 8.38.

RFC5952 contains significant changes in text representation from RFC3513 and I am concerned that there might be RFC4006 compliant implementations that will no longer be legal with a MUST level use of RFC5952. e.g. Addresses with upper case hex digits, with leading zeroes in 16 bit fields etc. Has the working group considered this break in compatibility already in its discussions?

If it has, this text should still be finessed a bit because RFC5952 recommendations (even at the MUST level) are a SHOULD for senders with the receivers being required to handle all possible legal formats as per RFC4291. So at least the sender rules and receiver rules need to be written differently.

[Ballot comment]
Section 8.65

Any reason you are allowing encoding an IPv4 address as a IPv4-Mapped IPv6 Address while you can directly use address family 1 to encode it directly as an IPv4 address? This allows for two different encodings for the same address.

[Ballot comment]
Thanks for Joel for his OpsDir review - I looked at the diffs between 4006 and this, and am balloting based on that.
Helpful link for other ADs: http://tools.ietf.org/tools/rfcdiff/rfcdiff.pyht?url1=https://www.ietf.org/id/draft-ietf-dime-rfc4006bis-08.txt&url2=https://tools.ietf.org/rfc/rfc4006.txt

[Ballot discuss]
I support Alissa's Discuss point about sensitive AVPs.

I appear to have a different understanding of Section 5.6.2, though,
with a different potential issue (but again, it's possible that I'm
confused to how things work):

With the redirection schemes covered in Section 5.6.2, it sounds
like the user can be redirected (at the application protocol level,
e.g., HTTP or SIP) to a top-up server to purchase more credits.  I
don't see a way described how user agents can distinguish between a
Diameter-induced redirect and an attacker-induced redirect to a
(potentially phishing) site that accepts payment information.  To be
clear, the scenario here is that a user is using a credit-controlled
application session to talk to "arbitrary application servers",
including potentially attacker-controllled HTTP/SIP/etc. servers;
the attacker could introduce a redirect to a phishing page that asks
for payment information, and the user would be led to believe that
this was the normal flow for "my prepaid balance has been used up",
and give their payment information to the phishing site. I think
that either user agents need to give some indication that this
DIAMETER-level redirect is different than an
application-protocol-level redirect (e.g., http) or the Security
Considerations need to mention the risk of acclimating users to
arbitrary websites redirecting to sites asking for payment
credentials, which may or may not be legitimate sites.

Separately, in Section 8.68 (for QoS-Final-Unit-Indication):

  If the Final-Unit-Action AVP is set to REDIRECT at least the
  Redirect-Server-Extension AVP MUST be present.

This MUST seems in conflict with the text in 8.64 (actually, is
section 8.64 even internally inconsistent, too?) about
"Redirect-Server AVP, in addition to or instead of the
Redirect-Server-Extension AVP", in particular, the "instead of"
portion.  (The ABNF-based formal language spec in 8.68 does match up
with the above MUST, though.)

[Ballot comment]
Some additional significant but not necessarily DISCUSS-worthy
comments, followed by more editorial- and nit-level things.

In Section 1.3, "Advertising Application Support" uses the same
Auth-Application-ID value as for RFC 4006; what are the interop
consequences of this?

Alissa already noted that the text about how to split (sub-)AVPs
between the foo and foo-Extension AVPs is inconsistent among them --
e.g., Redirect-Server-Extension and User-Equipment-Info say "SHOULD
send [in the old one]", but Subscription-Id-Extension has separate
text about "[i]f full backward compatibility with [RFC4006] is
required" and slightly different behavior described.  We should try
to catch all instances of this sort of backwards compatibility and
make them consistent.

The use of UTF8String for URLs and URIs (e.g., Redirect-Address-URL)
might benefit from additional text about the expected contents.  A
lot of the time when we use a UTF8 container for names (whether
domain names or other kinds), we specify what normalization form and
canonicalization are performed, whether domain names are A-labels or
U-labels, etc., as there's a lot of potential flexibility not all of
which is good.  In this case, since the communication is only
between trusted actors, perhaps the additional restrictions are not
needed, but I am curious if the topic was raised in the WG.

Thank you for adding the Privacy Considerations and list of
Privacy-Sensitive AVPs!

Section 14

  [...] The Diameter credit-
  control application is often used within one domain, and there may be
  a single hop between the peers.  In these environments, the use of
  TLS/TCP, DTLS/SCTP or IPsec is sufficient.

I did not see any concrete guidance on what would suffice in other
environments (with multiple hops between peers).  Is this the realm
of the mythical "end-to-end security mechanism" for Diameter that is
much-desired?  (The last paragraph does have guidance on what might
*not* suffice, which is not exactly the same thing.)

  Even without any modification to the messages, an adversary can
  eavesdrop on transactions that contain privacy-sensitive information
  about the user.

This ("an adversary can") makes it sounds as if there is no
confidentiality protection anywhere in the system, but that's what
TLS/DTLS/IPSec are supposed to provide.  So maybe "an adversary that
can eavesdrop on transactions can obtain privacy-sensitive
information [...]" is better.

(Editorial- and nit-level stuff follows.)

Section 4

  A flexible credit-control application specific failure handling is
  defined in which the home service provider can model the credit-
  control client behavior according to its own credit risk management
  policy.

This sentence is hard to parse -- in "credit-control application
specific" what does "specific" bind to?  What is being modelled?  Is
anything being controlled (as opposed to modelled)?

Section 4.1.1

  2.  The Service-Parameter-Info AVP MAY be used as a container to pass
  legacy rating information in its original encoded form (e.g., ASN.1
  BER).  [...]

Why BER and not DER?  The unnecessary flexibility in BER vs. DER has
been known to tickle parser bugs and create security
vulnerabilities.

Section 4.1.2

  [...] To
  facilitate interoperability, it is RECOMMENDED that the rating input
  and the values of the Service-Context-Id be coordinated via an
  informational RFC or other permanent and readily available reference.
  The specification of another cooperative standardization body (e.g.,
  3GPP, OMA, or 3GPP2) SHOULD be used.

The RECOMMENDED and SHOULD seem slightly in conflict.

Section 5.1.1

As noted elsewhere, 60 seconds per minute does not always hold; it
seems that this text could be reworded to just talk about a
"constant rate" or "constant level per fixed time period" or
similar.

Section 5.1.2

  [...]
  timer (Section 13) every time a CCR message with the value
  UPDATE_REQUEST is sent while they are in PendingU state.  When
  answers to all pending messages are received, the state machine moves
  to OPEN state, and Tx is stopped.

Transmission, or the Tx timer (is stopped)?

Using a different title for Section 5.2.2 might make the parallel
between it and Section 5.2.1 more clear.  That is, perhaps something
like "First Interrogation Included with Authorization Messages".

Section 5.7

  [...] It is RECOMMENDED that the client complement the credit-
  control failure procedures with backup accounting flow toward an
  accounting server. [...]

Nit: it looks like there's a missing article here, maybe "a backup
accounting flow" is better.

  The AAA transport profile [RFC3539] defines the application layer
  watchdog algorithm that enables failover from a peer that has failed
  and is controlled by a watchdog timer (Tw) defined in [RFC3539].

Nit: Is it "the" watchdog algorithm or "an" watchdog algorithm?

Section 6.2

Should there be text indicating how the client indicates what
service the balance check is being requested for?

Section 8.54

Maybe give a section reference in RFC 3580 for how the formatting is
done?

Section 12

  [...] Initially, such Expert discussions take place on the AAA
  WG mailing list.

That list appears to be dead, suggesting that this text should be
updated.  (I also agree with Adam's comments about updating the IANA Considerations.)

Why is the disclaimer in Section B.4 (and other examples) not needed in Section B.3?

[Ballot discuss]
= Section 5.6.2 =

I'm having a little trouble understanding the expected behavior described in Section 5.6.2 so wanted to see if I'm just confused or if there is something to be clarified. The text says:

"In addition to the Redirect-Server AVP or Redirect-Server-Extension
  AVP, the credit-control server MAY include one or more Restriction-
  Filter-Rule AVPs, one or more Filter-Rule AVPs, or one or more
  Filter-Id AVPs in the Credit-Control-Answer message to enable the
  user to access other services (for example, zero-rated services).  In
  such a case, the access device MUST drop all the packets not matching
  the IP filters specified in the Restriction-Filter-Rule AVPs, Filter-
  Rule AVPs or Filter-Id AVPs.  If enforcement actions other than
  allowing the packets (e.g., QoS), are indicated in the Filter-Rule
  AVPs or Filter-Id AVPs, they SHOULD be performed as well.  In
  addition, if possible, to redirecting the user to the destination
  specified in the Redirect-Server AVP or Redirect-Server-Extension
  AVP."

It seems like if the server sends a Redirect-Server AVP or Redirect-Server-Extension AVP without any of the other AVPs, then all the traffic is supposed to be redirected. But if a Restriction-Filter-Rule AVP, Filter-Rule AVP, or Filter-Id AVP is also included, then the non-matching traffic MUST be dropped, in which case how does the user get redirected? Is the last sentence (which is a sentence fragment, actually) supposed to address this somehow? And in the case of enforcement actions involving QoS, the text seems to say that packets matching the filter MUST be dropped AND have the QoS rules applied to them, so I don't understand how that works.

= Section 15.1 =

RFC 6733 lists a bunch of sensitive AVPs and then says this about them:

"Diameter messages containing these or any other AVPs considered to be
  security-sensitive MUST only be sent protected via mutually
  authenticated TLS or IPsec.  In addition, those messages MUST NOT be
  sent via intermediate nodes unless there is end-to-end security
  between the originator and recipient or the originator has locally
  trusted configuration that indicates that end-to-end security is not
  needed."

It seems like the list of AVPs in Section 15.1 should have these same requirements applied to them explicitly.

[Ballot comment]
= Section 1 =

(1) I know it's a term of art, but the term "next generation wireless networks" seems a bit out of place in two ways: (1) "wireless" seems more generic than what is implied (i.e., "cellular," I assume), and (2) is Rel-13 considered "next generation" still?

(2) "Diameter base protocol" should cite RFC 6733.

= Section 5.1 =

Assuming G-S-U stands for granted service unit, the acronym should be given upon first use here.

= Section 8.52 =

(1) Why do you need to specify the ability to send either the IMEISV or the IMEI?


(2)
"If the type of the equipment is one of the
  enumerated types of User-Equipment-Info-Type AVP, then the credit-
  control client SHOULD send the information in the User-Equipment-Info
  AVP, in addition to or instead of the User-Equipment-Info-Extension
  AVP."

Why is this normative recommendation in support of backwards compatibility different from the one given for the Subscription-Id-Extension AVP in Sec. 8.58?

= Section 15.1 =

"Redirect-Server-Address AVP: the service-provider may embed
        personal information on the subscriber in the URL/I (e.g. to
        create a personalized message)."
   
This seems like a bad idea that, if it's going to be mentioned, should be recommended against.

[Ballot comment]
Thanks to the authors and other participants who helped with this revision of
the credit-control application. Thanks in particular for the addition of an
extensive privacy considerations section.

I will note that I only reviewed the diffs between this document and RFC 4006.

I have a handful of comments.

---------------------------------------------------------------------------

General nit:

This document uses the term "service specific" as a compound adjective in
several places. As a compound adjective, this should be hyphenated (i.e.,
"service-specific").

---------------------------------------------------------------------------

§1.1:

This document uses lowercase forms of RFC-2119-defined terms. Please update this
section to use the boilerplate from RFC 8174.

---------------------------------------------------------------------------

§5.1.2:

>  If independent credit-control of multiple services is used, the
>  Validity-Time AVP and Final-Unit-Indication AVP or QoS-Final-Unit-
>  Indication AVP SHOULD be present either in the Multiple-Services-
>  Credit-Control AVP(s) or at command level as single AVPs.

The phrasing here is ambiguous -- it's not clear whether the requirement is:

  (Validity-Time and Final-Unit-Indication) or QoS-Final-Unit-Indication

... or ...

  Validity-Time and (Final-Unit-Indication or QoS-Final-Unit-Indication)

I suspect it's the latter, in which case I suggest:

  If independent credit-control of multiple services is used, the
  Validity-Time AVP, and either the Final-Unit-Indication AVP or
  the QoS-Final-Unit-Indication AVP, SHOULD be present either in the
  Multiple-Services- Credit-Control AVP(s) or at command level as single
  AVPs.

---------------------------------------------------------------------------

§5.2.1:

The alignment of the "Diameter AAA Server" title on Figure 3 has changed from
RFC 4006 in a way that looks worse.

---------------------------------------------------------------------------

§5.6.2:

>  The credit-control
>  client receives a Credit-Control-Answer or service specific
>  authorization answer with the Final-Unit-Indication or the QoS-Final-
>  Unit-Indication AVP and Validity-Time AVPs but no Granted-Service-
>  Unit AVP.

This has the same confusion as above regarding the application of logical
combinations. The second half of the statement is of the form "A or B and C
but not D," which is pretty ambiguous. It's also a little unclear whether the
client receives a Credit-Control-Answer (with A or B and C but not D), or just
a Credit-Control-Answer of any description, full stop.

---------------------------------------------------------------------------

§8.19

>  Note: The values reported in a Used-Service-Unit AVP does not
>  necessarily have a relation to the grant provided in a Granted-
>  Service-Unit AVP, e.g., the value in this AVP may exceed the value in
>  the grant.

Nit: "...values reported in a Used-Service-Unit AVP do not..."
                                                    ^^

(or "...value... does not...")

---------------------------------------------------------------------------

§8.54:

>  The User-Equipment-Info-MAC (AVP Code TBD3) is of type OctetString.
>  The User-Equipment-Info-MAC AVP contains the 48-bit MAC address is
>  formatted as described in [RFC3580].

Nit: remove "is" after "address".

---------------------------------------------------------------------------

§8.65:

>  The Redirect-Address-IPAddress AVP (AVP Code TBD14) is of type
>  Address and defines the IPv4 or IPv6 address of the redirect server
>  with which the end user is to be connected when the account cannot
>  cover the service cost.

This appears to be underspecified, unless I've missed some specification
elsewhere regarding what the client is supposed to do with this IP address.
While the other redirection methods (HTTP, SIP) have relatively clear means of
contact (they indicate a protocol), the indication of only an IP address with
neither protocol nor port doesn't seem to provide enough information for a
client to act on.  Please either flesh this out in this section, or point to
another document that indicates how this IP address is to be used.

---------------------------------------------------------------------------

§12:

When new documents obsolete an RFC that originally registered values with IANA,
I'm used to seeing that document also update the IANA registry so that the
corresponding entries now point to the new document. You may consider text that
instructs IANA to update the existing RFC-4006-registered values so that they
point to this document instead of RFC 4006.

---------------------------------------------------------------------------

Appendix B:

As a general comment for all of the examples: I'm surprised that none of the
examples have been updated to reflect the newly defined capabilities in this
document. For example, all the examples in this appendix use
Final-Unit-Indication rather than QoS-Final-Unit-Indication. In practice, to
show maximally flexible and compatible examples, I would expect that the
examples would include both AVPs. This applies to all of the "Extension"
AVPs as well.

---------------------------------------------------------------------------

Appendix B.2:

>  control server.  Therefore, in this example, it is assumed that the
>  SIP Proxy adds a Record-Route header in the initial SIP INVITE

"...a Record-Route header field..."

(A SIP header is everything before the first blank line; individual lines within
a SIP header are called "header fields")

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

The IANA Services Operator has completed its review of draft-ietf-dime-rfc4006bis-07. If any part of this review is inaccurate, please let us know.

The IANA Services Operator has a question about one of the actions requested in the IANA Considerations section of this document.

The IANA Services Operator understands that, upon approval of this document, there are twenty-one actions which we must complete.

First, in the Application IDs registry on the Authentication, Authorization, and Accounting (AAA) Parameters registry page located at:

https://www.iana.org/assignments/aaa-parameters/

The existing registration for:

ID Value: 4
Name: Diameter Credit Control

has a reference of [RFC6733].

IANA Question --> Should the reference be changed to [ RFC-to-be ]?

Second, in the Command Codes registry on the Authentication, Authorization, and Accounting (AAA) Parameters registry page located at:

https://www.iana.org/assignments/aaa-parameters/

The existing registration for:

Code Value: 272
Name: CCR / CCA

has a reference of [RFC6733].

Third, section 12.3 of the current draft suggests that we should "see Section 8 for the assignment of the namespace in this specification."

IANA Question -> Section 8 of the current draft provides a table that appears to be AVP codes, but the table does not match the AVP code table on the Authentication, Authorization, and Accounting (AAA) Parameters registry page located at:

https://www.iana.org/assignments/aaa-parameters/

Is the table in Section 8 intended to be a new registry or a subset of the existing AVP Codes table? Could the authors redraft section 12.3 to explicitly show which AVP Codes are new additions, and which are restatements of existing registrations that should have their reference change?

Fourth, in the Result-Code AVP Values (code 268) - Transient Failures registry also on the Authentication, Authorization, and Accounting (AAA) Parameters registry page located at:

https://www.iana.org/assignments/aaa-parameters/

the existing values

4010
4011
4012

are already registered.

IANA Question --> Should the reference for these registrations be changed to [ RFC-to-be ]?

Fifth, in the Result-Code AVP Values (code 268) - Permanent Failure registry also on the Authentication, Authorization, and Accounting (AAA) Parameters registry page located at:

https://www.iana.org/assignments/aaa-parameters/

the existing values

5030
5031

are already registered.

IANA Question --> Should the reference for these registrations be changed to [ RFC-to-be ]?

Sixth, in the CC-Request-Type AVP registry also on the Authentication, Authorization, and Accounting (AAA) Parameters registry page located at:

https://www.iana.org/assignments/aaa-parameters/

Values 1 - 4 will remain in place and in the future, the registry will be maintained via Designated Expert as defined in RFC 8126.

IANA Question -> What are "all remaining values" for this registry that are currently unassigned?

Seventh, in the CC-Session-Failover AVP registry also on the Authentication, Authorization, and Accounting (AAA) Parameters registry page located at:

https://www.iana.org/assignments/aaa-parameters/

Values 0 and 1 will remain in place and in the future, the registry will be maintained via Designated Expert as defined in RFC 8126.

IANA Question -> What are "all remaining values" for this registry that are currently unassigned?

Eighth, in the CC-Unit-Type AVP registry also on the Authentication, Authorization, and Accounting (AAA) Parameters registry page located at:

https://www.iana.org/assignments/aaa-parameters/

Values 0 - 5 will remain in place and in the future, the registry will be maintained via Designated Expert as defined in RFC 8126.

IANA Question -> What are "all remaining values" for this registry that are currently unassigned?

Ninth, in the Check-Balance-Result AVP registry also on the Authentication, Authorization, and Accounting (AAA) Parameters registry page located at:

https://www.iana.org/assignments/aaa-parameters/

Values 0 and 1 will remain in place and in the future, the registry will be maintained via Designated Expert as defined in RFC 8126.

IANA Question -> What are "all remaining values" for this registry that are currently unassigned?

Tenth, in the Credit-Control AVP registry also on the Authentication, Authorization, and Accounting (AAA) Parameters registry page located at:

https://www.iana.org/assignments/aaa-parameters/

Values 0 and 1 will remain in place and in the future, the registry will be maintained via Designated Expert as defined in RFC 8126.

IANA Question -> What are "all remaining values" for this registry that are currently unassigned?

Eleventh, in the Credit-Control-Failure-Handling AVP registry also on the Authentication, Authorization, and Accounting (AAA) Parameters registry page located at:

https://www.iana.org/assignments/aaa-parameters/

Values 0 - 2 will remain in place and in the future, the registry will be maintained via Designated Expert as defined in RFC 8126.

IANA Question -> What are "all remaining values" for this registry that are currently unassigned?

Twelfth, in the Direct-Debiting-Failure-Handling AVP registry also on the Authentication, Authorization, and Accounting (AAA) Parameters registry page located at:

https://www.iana.org/assignments/aaa-parameters/

Values 0 and 1 will remain in place and in the future, the registry will be maintained via Designated Expert as defined in RFC 8126.

IANA Question -> What are "all remaining values" for this registry that are currently unassigned?

Thirteenth, in the Final-Unit-Action AVP registry also on the Authentication, Authorization, and Accounting (AAA) Parameters registry page located at:

https://www.iana.org/assignments/aaa-parameters/

Values 0 - 2 will remain in place and in the future, the registry will be maintained via Designated Expert as defined in RFC 8126.

IANA Question -> What are "all remaining values" for this registry that are currently unassigned?

Fourteenth, in the Multiple-Services-Indicator AVP registry also on the Authentication, Authorization, and Accounting (AAA) Parameters registry page located at:

https://www.iana.org/assignments/aaa-parameters/

Values 0 and 1 will remain in place and in the future, the registry will be maintained via Designated Expert as defined in RFC 8126.

IANA Question -> What are "all remaining values" for this registry that are currently unassigned?

Fifteenth, in the Redirect-Address-Type AVP registry also on the Authentication, Authorization, and Accounting (AAA) Parameters registry page located at:

https://www.iana.org/assignments/aaa-parameters/

Values 0 - 3 will remain in place and in the future, the registry will be maintained via Designated Expert as defined in RFC 8126.

IANA Question -> What are "all remaining values" for this registry that are currently unassigned?

Sixteenth, in the Requested-Action AVP registry also on the Authentication, Authorization, and Accounting (AAA) Parameters registry page located at:

https://www.iana.org/assignments/aaa-parameters/

Values 0 - 3 will remain in place and in the future, the registry will be maintained via Designated Expert as defined in RFC 8126.

IANA Question -> What are "all remaining values" for this registry that are currently unassigned?

Seventeenth, in the Subscription-Id-Type AVP registry also on the Authentication, Authorization, and Accounting (AAA) Parameters registry page located at:

https://www.iana.org/assignments/aaa-parameters/

Values 0 - 4 will remain in place and in the future, the registry will be maintained via Designated Expert as defined in RFC 8126.

IANA Question -> What are "all remaining values" for this registry that are currently unassigned?

Eighteenth, in the Tariff-Change-Usage AVP registry also on the Authentication, Authorization, and Accounting (AAA) Parameters registry page located at:

https://www.iana.org/assignments/aaa-parameters/

Values 0 - 2 will remain in place and in the future, the registry will be maintained via Designated Expert as defined in RFC 8126.

IANA Question -> What are "all remaining values" for this registry that are currently unassigned?

Nineteenth, in the User-Equipment-Info-Type AVP registry also on the Authentication, Authorization, and Accounting (AAA) Parameters registry page located at:

https://www.iana.org/assignments/aaa-parameters/

Values 0 - 3 will remain in place and in the future, the registry will be maintained via Designated Expert as defined in RFC 8126.

IANA Question -> What are "all remaining values" for this registry that are currently unassigned?

Twentieth, in section 13 of the current draft, there is a discussion of Credit-Control Application Related Parameters. Upon examining this section, we do not believe that there is any request for IANA action in this section.

IANA Question -> Is it correct that there is no IANA Action contained in section 13 of the current draft?

Twenty-first:

IANA Question -> Is there any other place in IANA registries where RFC4006 is referenced and should be changed to [ RFC-to-be ]?

The IANA Services Operator understands 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.

Thank you,

Sabrina Tanamal
Senior IANA Services Specialist

The following Last Call announcement was sent out (ends 2018-04-12):

From: The IESG
To: IETF-Announce
CC: ben@nostrum.com, jouni.nospam@gmail.com, Jouni Korhonen , draft-ietf-dime-rfc4006bis@ietf.org, dime-chairs@ietf.org, dime@ietf.org
Reply-To: ietf@ietf.org
Sender:
Subject: Last Call:  (Diameter Credit-Control Application) to Proposed Standard


The IESG has received a request from the Diameter Maintenance and Extensions
WG (dime) to consider the following document: - 'Diameter Credit-Control
Application'
  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 2018-04-12. 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 Diameter application that can be used to
  implement real-time credit-control for a variety of end user services
  such as network access, Session Initiation Protocol (SIP) services,
  messaging services, and download services.  The Diameter Credit-
  Control application as defined in this document obsoletes RFC4006,
  and it must be supported by all new Diameter Credit-Control
  Application implementations.




The file can be obtained via
https://datatracker.ietf.org/doc/draft-ietf-dime-rfc4006bis/

IESG discussion can be tracked via
https://datatracker.ietf.org/doc/draft-ietf-dime-rfc4006bis/ballot/


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

RFC 4006.
—————————————

Major Comment:

I strongly suggest that you add more privacy considerations. I realize that it inherits its existing privacy considerations from RFC 4006, but that was published in 2005. The IETF’s focus on privacy has evolved considerably since then, and I think this draft will get objections during IESG review without adding some more.

I suggest the following:
— Create a “Privacy Considerations” section separate from the security considerations.
— Enumerate the AVPs that you think contain user identifiable information, persistent identifiers, or other privacy sensitive data.
— Make some non-normative recommendations concerning data minimization. That is, add a few sentences recommending that clients and servers avoid capturing and/or log personal information beyond that needed for the application's purpose.

Minor Comments:

-Section 12 and subsections: Please clarify that many of these elements were already registered by RF 4006, and are not being “re-registered” here. ( It’s perfectly okay to pull the registration information forward into the bis draft; it just needs clarification.) Also, please consider wether existing registrations should be updated to point to this document rather than 4006.

Appendices: Would any of the example flows benefit from including one or more of the new AVPs?

Editorial and Nits:

-Section 8.34: “ If the Final-Unit-Action AVP is set to RESTRICT_ACCESS or REDIRECT
and the classification of the restricted traffic cannot be expressed
using IPFilterRule, or different actions (e.g., QoS) than just
allowing QoS needs to be enforced traffic, … “

I have trouble parsing the sentence.

-14: "Even without any modification to the messages, an adversary can
  invite a security threat by eavesdropping, as the transactions contain private information about the user.
”
I suggest “ … an adversary can eavesdrop on transactions that contain privacy-sensitive imformation”

As required by RFC 4858, this is the current template for the Document
Shepherd Write-Up.

Changes are expected over time. This version is dated 24 February 2012.

(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?

  Standards Track and it is indicated on the title page.

(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 will obsolete RFC4006. This document specifies a Diameter application
  that can be used to implement real-time credit-control for a variety of end user services.

Working Group Summary

  WG has a solid support for this document.

Document Quality

  3GPP has adopted RFC4006 and it has been widely implemented, deployed
  and in production use basically in every cellular carrier with LTE deployment.
  The changes/updates described in this specification are not deployed but
  being one of the core Diameter specifications in 3GPP there are high probability
  it getting a wide deployment. Maintaining backward compatibility was one of the
  design guidelines. The update to RFC4006, which this document is, was  requested
  by 3GPP.
 
  There has not been any expert reviews of the document. 3GPP
  CT3 and CT4 should review the document before its publication.

Personnel

  Jouni Korhonen (jouni.nospam@gmail.com) is the document shepherd.
  Ben Campbell (ben@nostrum.com) is the responsible AD.

(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 shepherd was part of the initial team thinking the changes required and how
  to proceed with those. During the publication process the shepherd has done
  review on the parts of the document required when writing the proto write-up.

(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.

  The document should be reviewed by AAA doctors and 3GPP CT3/CT4 WGs.

(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. There is just the generic issue with Diameter enums that has changed
  since the publication of the original RFC4006, which is described in RFC7423
  and reflected in the IANA considerations that list the AVPs type of enum and
  requiring designated expert review.

(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 IPRs disclosed with this update of the RFC.

(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? 

  Solid WG consensus behind 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.)

  None.

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

  None that matter. Downrefs are discussed in step 15)

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

  None required.

(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?

  None.

(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.

  Following downward references exists:
  -- Possible downref: Non-RFC (?) normative reference: ref. 'CE164'
  -- Possible downref: Non-RFC (?) normative reference: ref. 'CE212'
  -- Possible downref: Non-RFC (?) normative reference: ref. 'E164'
  -- Possible downref: Non-RFC (?) normative reference: ref. 'E212'
  -- Possible downref: Non-RFC (?) normative reference: ref. 'EUI64'
  -- Possible downref: Non-RFC (?) normative reference: ref. 'ISO4217'
  -- Possible downref: Non-RFC (?) normative reference: ref. 'TGPPIMEI'

  All these are normative required references to documents/specifications outside IETF.

(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.

  This document obsoletes RFC4006 and it is listed in appropriate places
  in the document. This document is an update based on the original RFC4006.

(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).

  The IANA requirements were checked against RFC8126 not the
  obsoleted RFC5226. The document defines 17 new AVPs that are listed in
  Section 8. No new registries are created.

  The IANA considerations for AVPs of type enum and the associated existing RFC4006
  created IANA registry have a new additional clarification:
  "All remaining values are available for assignment by a Designated Expert [RFC8126],
  under the conditions for enumerated values described in [RFC7423] Section 5.6."

(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.

  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.

Need to check NITs and small things.

** Obsolete normative reference: RFC 1738 (Obsoleted by RFC 4248, RFC 4266)
** Obsolete normative reference: RFC 2434 (Obsoleted by RFC 5226)

Below one is most likely intentional as it was like this in RFC4006 already:
** Downref: Normative reference to an Informational RFC: RFC 3580

Request for posting confirmation emailed to previous authors: Marco Stura , " ylifshitz@sandvine.com" , John Loughney , Leena Mattila , Juha-Pekka Koskinen , dime-chairs@ietf.org, Lyle Bertz , David Dolson , Harri Hakala