Subject: [sipcore] WGLC: draft-ietf-sipcore-reason-q850-loc

From: "A. Jean Mahoney" <[email-masked]>
Date: Fri, 2 Feb 2018 12:09:37 -0600

Hi all,

Working Group Last Call starts today for 
draft-ietf-sipcore-reason-q850-loc.

https://datatracker.ietf.org/doc/draft-ietf-sipcore-reason-q850-loc/

Please provide any feedback to the sipcore mailing list by Friday, 
February 16th.

Thanks!

Jean

---

From: [email-masked] (Dale R. Worley)
Date: Sun, 04 Feb 2018 15:12:25 -0500

Of course, I support advancing this document.

Technical question:

- The last sentence of section 4 says (when typos are corrected):

   The use of the location parameter is restricted to Q.850 cause
   values. In other cases the location parameter, if present, MUST be
   silently discarded.

However, it seems to me that this text requires that such a value must
be removed from any Reason header that passes through a device.
Instead, I think it better to word it "MUST be silently ignored".  This
allows an intermediate device to pass through the value, while ensuring
that no (conforming) device is affected by the parameter.  OTOH, an
intermediate device could "ignore" the value by removing it.

Some nits of various sorts (in the -02 version):

- The terms ISUP, IMS, and ISDN are used in the document.  I do not
  understand the exact distinctions between them, but it seems to me
  that there might be some problems, and the uses should be carefully
  checked.  In particular, "ISDN" is used only once, at the end of
  section 3, and it seems to me that "ISUP" might be intended.  Then
  again, "ISDN" appears in the title of reference [Q.850].

- In section 4 figure 1, the entry 0100 is coded "RLN", whereas
  comparing with the other entries, "RN" would be more systematic.
  Nonetheless, ITU Q.850 clause 2.2.3 gives the coding "RLN" for this
  value.  So this entry is correct.

- In section 4 figure 1, the final line gives the value "1 1 1 0",
  whereas the value "1 1 1 1" is intended.

- The last sentence of section 4 needs some minor corrections:

   The use of the location header is restricted to Q850 cause values in
   other cases the location, if present, MUST be silently discarted.

  becomes

   The use of the location parameter is restricted to Q.850 cause
   values. In other cases the location parameter, if present, MUST be
   silently discarded.

- In section 5 figure 2, the Reason header is split onto two lines, but
  the second line is not shown as starting with whitespace.  (I point
  this out because it's a simple editorial matter but the RFC Editor
  might overlook it.)  Also, there is an initial line in the figure,
  "404 Not Found", which seems to be extraneous.  Corrected, this
  becomes:

         SIP/2.0 404 Not Found

         From: Alice <sips:[email-masked]>;tag=1234567
         To: Bob <sips:[email-masked]>;tag=765432
         Call-ID: [email-masked]
         CSeq: 1 INVITE
         Reason: Q.850;cause=1;text="Unallocated (unassigned) number";
                 location=LN
         Content-Length: 0

- In section 7, "security constrain" should be "security constraint".

- The title of section 8.1 is not capitalized in the same way as the other
  titles.  Also, the word "reason" is specifically the keyword of the
  "Reason" header and thus it should be capitalized regardless of the
  capitalization scheme used.

- It seems to me that the *parameter* is named "location", whereas the
  *grammar symbol* is "isup-cause-location".  But there are some
  situations, including the title of section 8.1, there the latter is
  used where the former is needed.

- Should [Q.850] be made a normative reference?  It seems to me that
  this document is what defines the meanings of the location values.

Dale

---

From: <[email-masked]>
Date: Wed, 7 Feb 2018 13:01:00 +0000

Hi Dale,
Thank you for your review and comments.
For the answers please see inline.
I will provide a version 03 as soon I got all comments.

Best Regards

Roland

> -----Ursprüngliche Nachricht-----
> Von: sipcore [mailto:[email-masked]] Im Auftrag von Dale R.
> Worley
> Gesendet: Sonntag, 4. Februar 2018 21:12
> An: [email-masked]
> Betreff: Re: [sipcore] WGLC: draft-ietf-sipcore-reason-q850-loc
> 
> However, it seems to me that this text requires that such a value must be
> removed from any Reason header that passes through a device.
> Instead, I think it better to word it "MUST be silently ignored".  This allows an
> intermediate device to pass through the value, while ensuring that no
> (conforming) device is affected by the parameter.  OTOH, an intermediate
> device could "ignore" the value by removing it.

OK I have changed it in my draft for Version 03.

>   again, "ISDN" appears in the title of reference [Q.850].

For ISDN and ISUP is the binding --> ISDN User Part (ISUP)
IMS (IP Multimedia Subsystem) which has a interworking to SS7 (ISUP) Networks

Solution: I have added the full name of IMS where it was mentioned and the clarification of ISUP as follows --> ISDN User Part (ISUP)

>   value.  So this entry is correct.
OK

>   whereas the value "1 1 1 1" is intended.

OK I have changed it
>    values. In other cases the location parameter, if present, MUST be

OK I have changed it.

>          Reason: Q.850;cause=1;text="Unallocated (unassigned) number";

OK done
> - In section 7, "security constrain" should be "security constraint".

OK done
>   capitalization scheme used.

OK done
>   used where the former is needed.

OK done
>   this document is what defines the meanings of the location values.
Yes you are right. I have changed this.

> Dale
> 
> _______________________________________________
> sipcore mailing list
> [email-masked]
> https://www.ietf.org/mailman/listinfo/sipcore

---

From: <[email-masked]>
Date: Tue, 13 Feb 2018 03:55:37 +0000

Dear all,
since I did not get any further comments till yesterday and no further discussion is open on the list, I have generated a Version 03. To give people the chance to have a look on the changes till now before WGLC ends.

The IETF datatracker status page for this draft is:
https://datatracker.ietf.org/doc/draft-ietf-sipcore-reason-q850-loc/

There are also htmlized versions available at:
https://tools.ietf.org/html/draft-ietf-sipcore-reason-q850-loc-03
https://datatracker.ietf.org/doc/html/draft-ietf-sipcore-reason-q850-loc-03

A diff from the previous version is available at:
https://www.ietf.org/rfcdiff?url2=draft-ietf-sipcore-reason-q850-loc-03

Further comments are welcome.

Thank you and Best Regards

Roland

> Von: Jesske, Roland
> Gesendet: Mittwoch, 7. Februar 2018 14:01
> An: 'Dale R. Worley' <[email-masked]>; [email-masked]
> Betreff: AW: [sipcore] WGLC: draft-ietf-sipcore-reason-q850-loc
> 
> Hi Dale,
> > Instead, I think it better to word it "MUST be silently ignored".
> > This allows an intermediate device to pass through the value, while
> > ensuring that no
> > (conforming) device is affected by the parameter.  OTOH, an
> For ISDN and ISUP is the binding --> ISDN User Part (ISUP) IMS (IP
> Multimedia Subsystem) which has a interworking to SS7 (ISUP) Networks
> 
> Solution: I have added the full name of IMS where it was mentioned and the
> clarification of ISUP as follows --> ISDN User Part (ISUP)
>