[LINK] Ported telephone numbers

[Paul Brooks]

On 10/01/2018 12:04 PM, David wrote:
> On Wednesday, 10 January 2018 9:57:35 AM AEDT Paul Brooks wrote:
>
>> Feel free to ping me off-list if you'd like to delve in to this deeper, and who your gaining provider is.
> Thanks...  This is an area which doesn't get much exposure amid all the sound & fury of NBN implementation.  But it seems important because "porting" papers over a fundamental issue with network addressing: traditional POTS addressing is a bit irrelevant in a VoIP-based network (as ACMA have stated in a strategy paper), especially one with so many providers and a volatile customer base.

Sure - but we don't have a VoIP-based network, we have for decades had a
Multi-Technology-MIx voice network, with sections using POTS, ETSI ISDN, ANSI ISDN,
VoIP with SIP signalling, VoIP with H.248 signalling, VoATM, and TDM SDH with
SS7/IISUP signalling, others I've forgotten.   All of these are part of the PSTN, and
the traditional telephone number addressing is the Universal Voice Glue that makes it
all work together relatively seamlessly, and lets someone on a POTS line call someone
on IP line without having to be aware of what technology the receiver is using at that
moment. Not quite irrelevant!.

> I see, I'd assumed the mandatory requirement to publish a PLNR ("Ported Local Number Register") file was intended to allow all carriers to route calls directly to the carrier currently holding a ported number without going through the donor carrier.  But the whole idea might be suffering scability problems now.
That is the idea - but also, even interconnect arrangements are bilateral as well.
'Your' carrier may not even have a bilateral network interconnect directly with the
final destination network hosting the number, and may have to route the call through a
third network who will provide the transit connectivity (who might or might not be the
original donor carrier) - who will do a second lookup of the PLNR in the process to
work out which direction to forward the call to.

I believe there is a transition window for a newly ported number where the donor
network will, for a time, accept a call and forward it through to the new network, to
have calls work properly during the delay while all the carriers refresh and update
their collection of all the other providers' PLNR files and consolidate them to start
directing them toward the new network, which might (guess) take a few days, maybe a
week for the less diligent ones.

> The other problem I haven't found a precise definition of the meaning of the 'LNP' flag in the EPID.  Do you know off the top of your head?
No - but it will be documented in one or more CommsAlliance operational documents
somewhere :)

ALso - Mobile Number Portability uses a completely different process and different
form of porting registers. Keeps the IT departments in the various OSS groups in the
carriers off the streets.

Paul.