Subject: RE: [Enum] A proposal for Carrier ENUM

From: "Pfautz, Penn L, NEO" <[email-masked]>
Date: Tue, 11 Oct 2005 09:25:47 -0400

Klaus:
Unfortunately not all portability implementations use network databases
(I assume it's network databases rather
Rather than admin ones to which you refer) Maybe some of those whose
countries use "onward routing" etc. can confirm
whether there is any centralized database outside of the network
detailing those arrangements. 

Nonetheless, I do think that for the most part it will be possible to
determine who the carrier providing the PSTN point of interface for an
E.164 number is and thus the carrier-of-record for carrier ENUM. If this
information were not generally available the E.164 number would not be
of much use anyway. I could think of workarounds even in the
non-centralized LNP situations and, frankly, if those cause some pain,
if should be thought of in terms of penance for making an erroneous
choice with respect to the implementation of number portability. (:-)

The day may/should/will come when interconnection is all IP-based and
some form of ENUM Registry IS the database of record for number
assignment and then we can have a debate about what it means to be
carrier of record again, but for now the approach of using the entity
that provides the number assignment/PSTN PoI is, I think, quite
workable.

Penn Pfautz

-----Original Message-----
From: [email-masked] [mailto:[email-masked]] On Behalf Of
Nieminen Klaus
Sent: Tuesday, October 11, 2005 9:00 AM
To: [email-masked]
Subject: RE: [Enum] A proposal for Carrier ENUM

Hello, 

One clarification:

> -----Original Message-----
> From: [email-masked] [mailto:[email-masked]] On Behalf
Of Stastny Richard
> Sent: 11. lokakuuta 2005 14:28
> To: Antoin Verschuren; [email-masked]
> Subject: RE: [Enum] A proposal for Carrier ENUM
> 
>> In the private contract between the terminating party and number
>> holder, the terminating party can simply insist that the contract is
only
>> valid (they can only offer the service) if the number holder enters
his 
>> numberblock in the Carier ENUM tree, delegating it to the terminating

>> party. The carrier ENUM tree is then simply the place where a
>> carrier-of-record is defined, as the NRA does not have this
information.
>
> Is it true that the NRA does not have this information?

At least in some cases NRAs do not have information about the network
that serves the numbers directly assigned to the users. I do not know,
if the same problem exists also for number ranges assigned to telcos,
but I assume that this may be tha case at least for numbers that are
further delegated to other service providers (e.g. Skype) by a contract.

For ported numbers I believe that all implementations involve the use of
databases that contain information on the network with which ported
numbers are associated. Therefore this should not be a problem.

regards,

- Klaus -
___________________________________________
KLAUS NIEMINEN
Senior Adviser
Finnish Communications Regulatory Authority
Internet and Information Security
P.O. Box 313
FIN-00181 HELSINKI
FINLAND
tel.: +358 9 6966 634
fax: +358 9 6966 873
e-mail: [email-masked]
www: http://www.ficora.fi

_______________________________________________
enum mailing list
[email-masked]
https://www1.ietf.org/mailman/listinfo/enum

_______________________________________________
enum mailing list
[email-masked]
https://www1.ietf.org/mailman/listinfo/enum

---

From: Otmar Lendl <[email-masked]>
Date: Tue, 11 Oct 2005 15:41:21 +0200

On 2005/10/11 15:10, "Pfautz, Penn L, NEO" <[email-masked]> wrote:
>
>                                            Maybe some of those whose

Austria uses onward routing for fixed line NP. There is no centralized
DB which shows which number has been ported to whom.

The NRA only keeps tabs on what number have been ported, but this
DB does not include the information necessary to route calls.

/ol
-- 
< Otmar Lendl ([email-masked]) | nic.at Systems Engineer >

---

From: "Clive D.W. Feather" <[email-masked]>
Date: Fri, 14 Oct 2005 15:36:20 +0100

> DB which shows which number has been ported to whom.

The same is true in the UK.

> DB does not include the information necessary to route calls.

The UK doesn't even have that. It's a commercial arrangement between the
two operators. [The existence of the arrangement is mandated by EU
Directives, but the details aren't.]

-- 
Clive D.W. Feather  | Work:  <[email-masked]>   | Tel:    +44 20 8495 6138
Internet Expert     | Home:  <[email-masked]>  | Fax:    +44 870 051 9937
Demon Internet      | WWW: http://www.davros.org | Mobile: +44 7973 377646
Thus plc            |                            |

---

From: "Clive D.W. Feather" <[email-masked]>
Date: Fri, 14 Oct 2005 15:39:46 +0100

Pfautz, Penn L, NEO said:
> of much use anyway.

In the UK model, the national call routeing system points at the "donor
operator". Calls are routed to that operator, who then adds a prefix to the
number - pointing at the terminating operator - and re-injects the call
into the network to be re-routed. Thus to identify the carrier providing
the PSTN point of interface:
(1) You need to identify the donor operator.
(2) You need to ask the donor operator to indicate whether the number has
    been ported and, if so, who the recipient operator is.

It's (2) that's the hard bit, because there is no mechanism for it and no
commercial or regulatory imperative to create one.