Re: [CCAMP] [Isis-wg] [Technical Errata Reported] RFC4920 (4480)

Adrian -

The definitive document on OSI addressing is ISO 8348 (Annex A and B). Freely available here: http://standards.iso.org/ittf/PubliclyAvailableStandards/c035872_ISO_IEC_8348_2002(E).zip

Some text in ISO 10589 Section 7.1 is also helpful.

But if you don't want to wade through the documents (for which I would not blame you :-) ) here's the short version: An area address is 1 - 13 octets in length - so at a quick read the proposed text in the errata seems to be correct.

   Les

> -----Original Message-----
> From: Isis-wg [mailto:isis-wg-bounces@ietf.org] On Behalf Of Adrian Farrel
> Sent: Friday, September 25, 2015 5:16 AM
> To: ccamp@ietf.org
> Cc: isis-wg@ietf.org; teas@ietf.org
> Subject: Re: [Isis-wg] [Technical Errata Reported] RFC4920 (4480)
> 
> All,
> 
> This email is copied to TEAS and ISIS, but it would be really helpful if any
> discussion was held to one list. CCAMP is probably best because they "own"
> RFC 4920.
> 
> The CCAMP chairs asked me to look into this as one of the original authors,
> and I have to say it has been so long that I can't recall the answer.
> 
> However, I looked at RFC 1195 and found section 3.3 gave me that the full
> description of an Area ID as:
> 
> >         AFI       1 octet       value "47" (specifies ICD format)
> >
> >         ICD       2 octet       value "00 05" (specifies Internet/Gosip)
> >
> >         DFI       1 octet       value "xx"
> >
> >         AA        3 octets      value "xx xx xx" (specifies special
> >                                 IP-only use of NSAPs)
> >
> >         Reserved  2 octets      must be "00 00"
> >
> >         RD        2 octets      contains autonomous system number
> >
> >         Area      2 octets      must be assigned as described below
> 
> This implies (to me) that an Area ID must be at least the trailing two octets,
> but may be given more context reading up this table up to a maximum of 13
> octets.
> 
> All I deduce from this is that I am consistent in my ability to reproduce my
> processing, not that I am right.
> 
> Can someone with IS-IS clue please comment:
> What are the max and min string lengths of an "area ID" in IS-IS?
> 
> Thanks,
> Adrian
> 
> > -----Original Message-----
> > From: RFC Errata System [mailto:rfc-editor@rfc-editor.org]
> > Sent: 21 September 2015 06:55
> > To: adrian@olddog.co.uk; asatyana@cisco.com; a-iwata@ah.jp.nec.com; n-
> > fujita@bk.jp.nec.com; gash5107@yahoo.com; akatlas@gmail.com;
> > db3546@att.com; aretana@cisco.com; daniele.ceccarelli@ericsson.com;
> > zhangfatai@huawei.com
> > Cc: dhruv.ietf@gmail.com; ccamp@ietf.org; rfc-editor@rfc-editor.org
> > Subject: [Technical Errata Reported] RFC4920 (4480)
> >
> > The following errata report has been submitted for RFC4920, "Crankback
> > Signaling Extensions for MPLS and GMPLS RSVP-TE".
> >
> > --------------------------------------
> > You may review the report below and at:
> > http://www.rfc-editor.org/errata_search.php?rfc=4920&eid=4480
> >
> > --------------------------------------
> > Type: Technical
> > Reported by: Dhruv Dhody <dhruv.ietf@gmail.com>
> >
> > Section: 6.2
> >
> > Original Text
> > -------------
> > For types 10 and 23, the Value field has the format:
> >
> >        0                   1                   2                   3
> >        0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
> >       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
> >       |   Length      |     IS-IS Area Identifier                     |
> >       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
> >       ~                     IS-IS Area Identifier (continued)         ~
> >
> > +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
> >
> >        Length
> >
> >           Length of the actual (non-padded) IS-IS Area Identifier in
> >           octets.  Valid values are from 2 to 11 inclusive.
> >
> > Corrected Text
> > --------------
> > For types 10 and 23, the Value field has the format:
> >
> >        0                   1                   2                   3
> >        0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
> >       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
> >       |   Length      |     IS-IS Area Identifier                     |
> >       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
> >       ~                     IS-IS Area Identifier (continued)         ~
> >
> > +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
> >
> >        Length
> >
> >           Length of the actual (non-padded) IS-IS Area Identifier in
> >           octets.  Valid values are from 1 to 13 inclusive.
> >
> > Notes
> > -----
> > IS-IS area IDs can vary from 1 to 13 bytes in length (max NSAP length
> > is 20,
> minus
> > 1 byte for NSEL, minus 6 bytes for SysID).
> >
> > *Noted by Jonathan Hardwick in another document that was using the
> > same data.
> >
> > Instructions:
> > -------------
> > This erratum is currently posted as "Reported". If necessary, please
> > use "Reply All" to discuss whether it should be verified or rejected.
> > When a decision is reached, the verifying party (IESG) can log in to
> > change the status and edit the report, if necessary.
> >
> > --------------------------------------
> > RFC4920 (draft-ietf-ccamp-crankback-06)
> > --------------------------------------
> > Title               : Crankback Signaling Extensions for MPLS and GMPLS
> RSVP-TE
> > Publication Date    : July 2007
> > Author(s)           : A. Farrel, Ed., A. Satyanarayana, A. Iwata, N. Fujita,
> G. Ash
> > Category            : PROPOSED STANDARD
> > Source              : Common Control and Measurement Plane
> > Area                : Routing
> > Stream              : IETF
> > Verifying Party     : IESG
> 
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