Subject: RE: [Enum] Re: draft-ietf-enum-e164-dns-03.txt

From: BARNOLE Valerie FTRD/DAC/ISS <[email-masked]>
Date: Thu, 10 Aug 2000 17:27:42 +0200

So a user dialing on his PC a number with a "+" in front indicates to the
system that it has to look through e164.arpa rather than in the originating
country of the call, namely Sweden and e164.se in your example ?
A maybe trivial question :
How does the system knows that it has to go through telia.se rather than
through e164.se in case Telia operator decided to put its customers numbers
in a DNS zone telia.se for any reason ? 

end of message
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 

Valérie Barnole

FTR&D/DAC/ACE

tel. : + 33 1 45 29 58 39
fax : + 33 1 46 29 31 42

mail to : [email-masked]

-----Message d'origine-----
De: Patrik Fältström [mailto:[email-masked]]
Date: jeudi 10 août 2000 16:38
À: Manfredi, Albert E; 'Hong Liu'
Cc: [email-masked]'
Objet: RE: [Enum] Re: draft-ietf-enum-e164-dns-03.txt

At 09.48 -0400 00-08-10, Manfredi, Albert E wrote:
>If the DNS query is made to domain e164.arpa, perhaps use of the + is
>redundant and not particularly helful for the future anyway?

If we start using some more interesting parts of the NAPTR 
algorithms/possibilities, it is possible to have an input to the 
algorithm (output of first well-known-rule) that is either a full 
E.164 number or some other kind of telephone number.

Let's say that we have for phone numbers in Sweden the TLD e164.se.

A phone number in Sweden can look like "08-978777", which without the 
'-' is 08978777.

Let's store that in DNS:

7.7.7.8.7.9.8.0.e164.se.

What do we now do?

Well, we can use the string we got 08978777 as input to a NAPTR 
rewrite mechanism where the flag field is empty, and because of that 
forces the rewrite to loop.

We can then store

7.7.7.8.7.9.8.0.e164.se. IN NAPTR 10 10 "" "" "![0-9].*!foo.se!" .

In parallell we have the full E.164 number +46-8-978777 (the same 
number) which have the DNS record 7.7.7.8.7.9.8.6.4.e164.arpa.

That NAPTR can look like

7.7.7.8.7.9.8.6.4.e164.arpa. IN NAPTR 10 10 "" "" "![0-9].*!foo.se!" .

Now, at foo.se, we want to distinguish between the "referals" which 
have been made from non-E.164 numbers and the ones which uses the 
full number (think of the two as two different dialling plans). How 
do we do that?

Well, the input to the algorithms are 08978777 and +468978777, and 
because of this different. We can because of that have two different 
NAPTR RRs at foo.se as follows:

foo.se. IN NAPTR 10 10 "u" "mailto+E2U" "!+.*!mailto:[email-masked]!" .
foo.se. IN NAPTR 10 10 "u" "mailto+E2U" "![0-9].*!mailto:[email-masked]!" .

Note that the regular expressions are different, and because of that 
only one of the two will match, and according to the NAPTR algorithm 
one should use the regexp which matches given that the repacement 
field is empty.

Also, note (of course) that the URIs which should be used are different.

So, I _really_ want the '+' there so it is simpler to know that we 
are talking about a real E.164 number and not something else 
(regardless of what it is) when dealling with regular expressions.

As usual, Michael will jump in if I have made an error :-)

     paf

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---

From: Patrik Fältström <[email-masked]>
Date: Thu, 10 Aug 2000 17:47:28 +0200

>country of the call, namely Sweden and e164.se in your example ?

No, I have not even started talking about the interface to the 
applications, but if _I_ wrote an application I would probably do it 
that way.

>in a DNS zone telia.se for any reason ?

Because it knows that E.164 numbers are handled in the e164.arpa 
domain, and the closed numbering plan somewhere else. When writing a 
spec for any closed numbering plan, you have to spec what TLD _that_ 
closed numbering plan is to use.

   paf