Re: [Dime] Problem with Origin- & Destination-Realm AVPs in RFC3588bis

Hi Jouni,

It is also my understanding.

Lionel 

> -----Message d'origine-----
> De : jouni korhonen [mailto:jouni.nospam@gmail.com] 
> Envoyé : jeudi 5 mars 2009 10:43
> À : Fortune HUANG
> Cc : 'Victor Fajardo'; MORAND Lionel RD-CORE-ISS; dime@ietf.org
> Objet : Re: [Dime] Problem with Origin- & Destination-Realm 
> AVPs in RFC3588bis
> 
> 
> Hi Fortune,
> 
> 
> On Mar 5, 2009, at 4:46 AM, Fortune HUANG wrote:
> 
> [snip]
> 
> 
> >
> > My conclusion after comparing the grammars of the three RFCs:
> > 1) According to the above RFC4282 grammar, "2.a " is a valid realm.
> 
> Correct.
> 
> >
> > 2) According to the above RFC4566 grammar, "2.a " is not a 
> valid FQDN 
> > since it has only 3 characters (not 4 or more).
> 
> First, RFC4566 ABNF is not in a role for defining FQDN.. it 
> is an ABNF for SDP grammar. So if the SDP grammar ABNF is 
> wrong, it is not the problem of original FQDN ABNF. Besides, 
> using "2.a" as an example is misleading. There is no root 
> zones that are one character long (see ICP-1, RFC1591). The 
> shortest root zone is two characters, which would e.g. be 
> "2.ac" and this is correct according to the ABNF in RFC4566.  
> The RFC1035 BNF would allow one character root zones, 
> however, those just do not exist in Internet DNS.
> 
> >
> > 3) According to the above RFC1035 grammar, "2.a" is not a 
> valid domain 
> > since it doesn't start with a letter (but a digit).
> 
> RFC1101 updates RFC1035 and relaxes the issue with a digit 
> being the first character.
> 
> 
> > If one could prove that the grammar of realm is the same as the 
> > grammar of FQDN,  then, RFC4282, RFC1035 and RFC4566 would 
> be proven 
> > inconsistent according.
> 
> So far, no problems with cases 2) and 3). Regarding the case 
> 1) few notes. RFC3588bis section 1.3. states that "NAI realm 
> names are required to be unique, and are piggybacked on the 
> administration of the DNS namespace." This basically means 
> one loses its rights for "creative" realm names when used 
> with Diameter. In DNS, one character root zones do not exist, 
> thus "2.a" is not legal within Diameter scope.
> 
> > However, I am not sure if I have found the right place where the 
> > strict grammar of FQDN is defined. Please tell me if you know.
> > But RFC4566 and RFC1035 were the materials my comment in 
> the previous 
> > email was based on.
> 
> Although this stuff is spread a bit around and topped with 
> de-facto assumptions, I think there is no issue.
> 
> Cheers,
> 	Jouni
> 
> 
> 
> 
> >
> >
> >
> > Best Regards,
> > Fortune
> >
> > -----Original Message-----
> > From: Victor Fajardo [mailto:vfajardo@tari.toshiba.com]
> > Sent: Thursday, March 05, 2009 6:02 AM
> > To: lionel.morand@orange-ftgroup.com
> > Cc: fqhuang@huawei.com; glenzorn@comcast.net; dime@ietf.org
> > Subject: Re: [Dime] Problem with Origin- & 
> Destination-Realm AVPs in 
> > RFC3588bis
> >
> > Hi Fortune,
> >> I'm not sure to understand but I might have missed something.
> >>> From a syntax point of view, what is the difference 
> between a FQDN 
> >>> and a
> > realm?
> >> What would be the "potential" impacts to say that the 
> >> DiameterIdentity can
> > be a FQDN or a realm?
> >>
> > I have the same question as Lionel. Syntactically, FQDN and 
> realm are 
> > the same from the parsers point of view. The difference is in 
> > semantics which is already specified by the AVP having that type.
> >
> > regards,
> > victor
> >
> > _______________________________________________
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> > DiME@ietf.org
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> 
> 