[asterisk-users] need creative solutions for number portability

[Alex Balashov]

Eric Fort wrote:
> I'm presently working on an office move and evaluation of 
> telecommunications services needed at the new location.  I'm presently 
> wrastling with an issue related to portability and geography between 
> landline carriers.  Presently certain people within the organization are 
> hopelessly in love with our 909-822-xxxx number(provided by 
> pacbell/att).  As that number is presently provisioned it rings to a 
> location geographically within 909-822 and forwards all calls to another 
> number 909-944-xxxx (Verizon)  Because of this toll is paid on all 
> incomming calls. )  

This is strange, because according to the tariffs, 909-822 and 909-944 
are in a local calling area with respect to each other.  It's not LD, so 
you should not be paying any tolls.  909-822 and 909-944 are blocks 
belonging to different ILECs, true, but they rate traffic as local 
between each other.

The source for this information is http://www.localcallingguide.com/ -> 
Area Code/Prefix/OCN.  Put in 909-822, click on it in the results, and 
you will get a list of all other rate centers local to it.

The information is not 100% accurate - it's published from commercial 
tariff research, and I am not sure exactly on what terms.

> The office is moving to another verizon area 
> (909-899, actually north fontana) and is just feet from the ATT/Verizon 
> border.  Verizon tells me the 909-822-xxxx number being held by ATT can 
> not be moved to ring direct into the new location, so toll charges for 
> inbound must still be paid.  I was hoping to avoid that.

909-899 is a local rate center to 909-822 as well.

Perhaps the issue has to do with the way they rate and provision "call 
forwarding" services vs. what is actually rated as a local call.

> What are the issues involved here?  Technically with SS7 it would seem a 
> number could ring anywhere.  my 909 npa cell phone works just fine when 
> on vacation in 941 or 808 and my 206 VoIP line finds me anywhere I have 
> a connection to the net.  What prevents this from being true with 
> landlines?  If this is a geograpic vs non-geographic issue then where 
> can I find street level maps of what wire center serves what area 
> thereby finding where to locate to be within a specific npa-nxx?  Other 
> than porting the number to VoIP, what solutions are available so inbound 
> calls incur no toll charges to the called party?

LocalCallingGuide.com is your best bet for this type of information. 
The real information is buried in thousands of pages of tariffs that the 
ILECs file and is sold in commercial guidebooks and databases by various 
consultancies that do this sort of thing, including some from Telcordia.

BTW, run away from anyone that advises you to get the LERG (Local 
Exchange Routing Guide) from Telcordia;  it's very useful, but has no 
information on local rate center coverage.

Regarding the "geographic" issue - none of the reasons for this is 
technical or geographic, but rather regulation and billing related:

Local carrier serving areas are split up into LATAs (Local Access and 
Transport Areas). [1]  LATAs are areas within which an ILEC operates, 
and within which any CLEC must be interconnected with the ILEC in order 
to provide service.  Traffic that traverses between LATA boundaries is 
known as IXC (Inter-Exchange Carrier) traffic, and this is a different 
type of carrier than a LEC.  However, certain types of intra-LATA 
traffic (traffic that stays in one LATA) can be rated long-distance too 
-- this is up to the fixed-line carrier.  Originally, LATAs were 
intended to be complete local calling areas, I think, but it never 
worked out that way, so long distance rating areas exist within LATAs as 
well as between them.  They can be very arbitrary.

All the rate centers and NPA-NXXs mentioned above are in LATA 730, and 
should be local calling areas according to the information given above. 
  Therefore, I am not sure what the basis of the carrier's suggestion 
that you should be paying LD tolls is, unless it is something that 
applies to their ring/forwarding service but not to straight-up calls.

If Verizon is an ILEC on the other side of that AT&T/Verizon border you 
mentioned, because it was a formerly GTE territory, then you can't port 
numbers across that border.  You are likely to be able to find a CLEC 
that interconnects with both carriers' tandems, though, and have them 
hang a number in whatever rate center you need.  But this should not be 
necessary since all these calls are local.

-- Alex

[1]  Enjoy a LATA map:  http://www.robotics.net/clec/LATA_Map.html

-- 
Alex Balashov
Evariste Systems
Web    : http://www.evaristesys.com/
Tel    : (+1) (678) 954-0670
Direct : (+1) (678) 954-0671
Mobile : (+1) (706) 338-8599