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Looking for some information on LERG

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rsvrl
Looking for some information on LERG

Hi,

I am new to telcom world.I am trying to understand the concepts of the telcom industry as I have started working on a telcom project. One of the component,i am working on in the project talks about LERG.I have a very basic idea that its a database and will have the information about the tns,but don't have any idea on what exact information it will have and how it is really used in call routing and who updates and who takes the data from it etc.

I would really appreciate if someone can point me in the right direction for this.If you have any slides/book/website links that has some information about this,i would appreciate if you can share it with me.

Thanks,
rsvrl

Edited by: admin on 05/16/2010 - 04:32
sunil.sunkari
Re: Looking for some information on LERG

Hi,

Here is the information which I am aware of regarding LERG database:

The Local Exchange Routing Guide, or LERG, is a nationally updated database that receives information from and sends information to every local carrier in the U.S.

The LERG database takes the area code, along with the first three digits of every phone number and geographically links this data to the phone number?s local carrier. (The combination of the area code and first three digits of the phone number is referred to as an NPA-NXX.)

The LERG database links this data to the physical location of the office that supplies service for that NPA-NXX. Whenever you make a phone call, your local carrier identifies the number you are dialing, checks its copy of the LERG database, and routes your call accordingly.

Example of LERG database : Table 3-1: LERG Database
NPA-NXX  Vertical  Horizontal  City/State  LATA
307-568    06668      06645      BASIN/WY  654
307-569    06668      06645      BASIN/WY  654

As you can see in the above example, every NPA-NXX is identified by city, state, and LATA. Each NPA-NXX is also identified by vertical and horizontal positions that act like GPS coordinates. The vertical and horizontal information is used by carriers to determine the distance between phone numbers. This is how your local carrier knows whether someone you are dialing is within the 13-mile radius for a local call, or whether you?re placing an intraLATA call.

rsvrl
Re: Looking for some information on LERG

Thanks a lot for the reply Sunil.That is really helpful.Do you have a block diagram or a presentation kind of to get more details on LERG. Like the information I am looking for is,how does the LERG get effected when a TN is ported into a carrier or TN gets ported out,also what is SPID and how is it linked with a TN/LRN and does the LERG gets effected wrt to SPID changes.Also,I heard something about NPAC Events?How are they related to LERG db?

Thanks once again.

sunil.sunkari
Re: Looking for some information on LERG

Hi ,

To get good information about NPAC database , please refer to the site http://www.npac.com.  It has all the information which I am aware of.

As said earlier, LERG database is used for Call routing. When ever there are TN's ported in and out, the NPAC database is updated. After the NPAC is updated, the LERG database is updated accordingly with in particular timelines. Even the carrier can go ahead with out the LERG information being updated but it would risk the call routing. NPAC's main functionality is to maintain LNP(Local number portablity). Hence whenever there is a change in NPAC a subsequent change should happen in LERG.

SPID is service provider ID.

I will try to get some more information for you about LERG.

rsvrl
Re: Looking for some information on LERG

Sunil,

I was trying to put together few slides on the LERG,as a part of education document for my team members.Do u have some links/materials on LERG so that I can add to my slides.

Thanks