When I was a kid my favorite sport was cricket. (Actually that’s still true.) I found cricket particularly appealing because it was chock-full of numbers. I could (and can) tell you that Don Bradman’s test batting average is 99.94, or that the highest score by an Englishman was Len Hutton’s 364 at the Oval in 1938. But beyond these famous numbers, the game was ripe for analysis by anyone who loved playing with databases and spreadsheets. After watching the movie Moneyball I have learned that in the US baseball is the equivalent sport – the sport for stats nerds.
Once I started working in telecoms it didn’t take long to realize that switch translations was the “fun” part for people who liked logic puzzles. But it’s not just an exercise in logic – accurate switch translations can only be built on top of accurate source data – and so today I’d like to tell you a little about the one database to rule them all. The LERG.
The LERG is a huge database, covering the North American Numbering Plan (NANP) and containing pretty much all the information anyone could need to know about the telephone network in North America (except local calling information, for some reason). For example, the LERG contains
- a list of all NPAs and LATAs
- geographic coordinates for every switch
- a list of all operating companies and a contact person at each company
- a list of all number blocks, which tandem they are “homed” to, and which company owns that number block.
There’s more but you get the idea.
Why is this important?
The LERG answers a lot of questions that should be important to a service provider. If you’re operating a class 5 switch, and you want to know if a call should be billed as intra-LATA, then you’ll need to know a list of all the number blocks within your LATA. Or if you have connections to multiple tandems, you’ll want to know which one to route a call to.
But the answers to these questions change – the information in the NANP is not static. At a high level, several new NPAs are created every year as demand for numbers grows, and smaller number blocks (NPA-NXXs, or thousand blocks) are frequently created or reallocated as demand for numbers ebbs and flows, and as companies are formed or acquired.
In other words, if you want to make sure that you route calls correctly and bill them correctly, you need to make sure that your switch translations reflect the current information in the LERG.
You call this fun?
I’m sure some of you are thinking: why would anyone get excited by logic puzzles and number databases? Well suffice to say, it takes a special type of person. I might get excited by cricket stats, but you should see how excited Rita gets when she has a copy of the LERG database and a “fun” translations problem to tackle.
If you want to learn more about switch translations then check out our podcast with Rita, or follow the excellent Teach Yourself Translations course on Metaswitch Communities.
Or if you’d rather someone else just handle this stuff for you, feel free to reach out the next time you have a translations-related project.
