Telechat Review of draft-ietf-ecrit-unauthenticated-access-08

Request Review of draft-ietf-ecrit-unauthenticated-access
Requested rev. no specific revision (document currently at 10)
Type Telechat Review
Team Security Area Directorate (secdir)
Deadline 2013-11-19
Requested 2013-10-31
Authors Henning Schulzrinne, Stephen McCann, Gabor Bajko, Hannes Tschofenig, Dirk Kroeselberg
Draft last updated 2013-11-04
Completed reviews Genart Last Call review of -07 by Alexey Melnikov (diff)
Genart Telechat review of -08 by Alexey Melnikov (diff)
Secdir Last Call review of -07 by Tina Tsou (diff)
Secdir Telechat review of -08 by Tina Tsou (diff)
Opsdir Telechat review of -08 by Dan Romascanu (diff)
Assignment Reviewer Tina Tsou
State Completed
Review review-ietf-ecrit-unauthenticated-access-08-secdir-telechat-tsou-2013-11-04
Reviewed rev. 08 (document currently at 10)
Review result Has Nits
Review completed: 2013-11-04


Dear all,

Some other nits:

* Section 1, page 2:

to PSAP URI by offering LoST [RFC5222] services.

Please expand the acronymns.

* Section 1, page 4:

  help may find himself/herself in, for example, a NAA and NASP

  situation, as explained in more details in Figure 1.


* Section 1, page 4:

We discuss each case in more details in Section 3.


* Section 5, page 8:

As an initial step the devices attaches to the network as shown in

     step (1).

* Section 5, page 8:

  o  When the link layer network attachment procedure is completed the

     end host learns basic IP configuration information using DHCP from

     the ISP, as shown in step (2).

Does this assume IPv4? (DHCPv6 is not mandatory for IPv6.)

* Section 5.1.3, page 10:

The description in Section 6.5 and 6.6

  of [RFC6881] regarding the interaction between the device and the LIS

  applies to this document.

s/6.6/Section 6.6/ -- this e.g. allows the html version of this document

to contain an hyperlink to the corresponding section of such RFC.

Section 6.1, page 13:

  o  Dependency on the specific access network architecture.  Access

     authorization and policy decisions typically happen at a different

     layers of the protocol stack and in different entities than those

     terminating the link-layer signaling.

s/different layers/different layer/

Thank you,


On Sep 27, 2013, at 3:57 PM, "Tina TSOU" <

Tina.Tsou.Zouting at

> wrote:

Dear all,

I have reviewed this document as part of the security directorate's ongoing effort to review all IETF documents being processed by the IESG.  These comments were written primarily for the benefit of the security area directors.  Document
 editors and WG chairs should treat these comments just like any other last call comments.


Draft-ietf-ecrit-unauthenticated-access-07 provides extensions to the emergency services architecture described in other documents to allow emergency services calling to proceed even when the caller is unauthenticated and unauthorized.
 The draft is particularly relevant to mobile devices, where such a situation is most likely to arise. It assumes separate entities provide network access and process calls at the application level, and based on that, deals with three cases, not necessarily
 mutually exclusive:

   -- no access authentication;

   -- no application service provider reachable;

   -- subscribed application service provider reachable but ordinary

      service denied because of zero credit balance or other reasons.

Full understanding of this document required review of RFC 5069 (security requirements specifically for emergency call marking and mapping), RFC 6443, the emergency calling framework, and RFC 6881, a BCP specifying requirements for various
 components of the emergency calling system beginning with the subscriber device.


The draft states that it is forward-looking, and is input for other SDOs. One example of this is the reliance on DHCP provisioning, which is at this point little-implemented in cellular devices.


General remark: the document is very heavy on abbreviations, which makes serious demands on the novice reader at some points. The terminology and abbreviations are introduced quite properly at the beginning of the document, but the authors
 might still ease the reader's task by spelling out at least the less-used abbreviations either whenever used (if only two or three times) or perhaps once per section.


General assessment: The document is basically ready, but lacks a statement of the specific points in RFCs 6443 and 6881 that need to be changed due to lack of authentication or authorization. As a result, the NASP and NAA sections are unmotivated.


Editorial: Section 7 in a few places does not quite seem to say what I think it means, hence the following suggestions:


Suggestion, sec. 7, fourth para, first sentence:

Currently: "We only illustrate a possible model."

Suggested: "We illustrate just one possible model for obtaining the destination addresses to which emergency callers should be restricted in the NAA case."


In the next sentence, missing some words: "... as well

    as the address of the LoST server itself."



Suggestion, sec. 7, fifth para, first sentence:

Currently: "For the ZBP case the additional aspect of fraud has to be considered."

Suggested: "The additional aspect of fraud also has to be considered for the ZBP case."





Typo, sec. 5, first bullet: devices -> device


Typo, sec. 7, second para, last sentence: lead -> led


Typo, sec. 7, third para, fourth line: fraudulent -> fraudulently


Thank you,