mathematics

Location routing number

Location routing number is a mathematics topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Location routing number rather than just read about it. In short: A location routing number (LRN) is a 10-digit number which identifies a telephone switch for the purpose of routing telephone calls through the public switched telephone network (PSTN). This identifier has the format of a telephone number in accordance with the North American Numbering Plan (NANP).

Key takeaways

Location routing number belongs to mathematics; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Location routing number to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Location routing number from memory before moving on to harder problems.

Reference excerpt

A location routing number (LRN) is a 10-digit number which identifies a telephone switch for the purpose of routing telephone calls through the public switched telephone network (PSTN). This identifier has the format of a telephone number in accordance with the North American Numbering Plan (NANP). The association of a location routing number to ported telephone numbers is required for local number portability.

Function An LRN identifies a switch in the PSTN that serves a given telephone number. The Number Portability Administration Center (NPAC) in the U.S. and the Canadian Number Portability Administration Center (CANPAC) in Canada administer several databases known as local number portability (LNP) databases across many NPAC Regions. Each telephone number entered into the NPAC is known a subscription version and is stored in an LNP. The subscription version contains, among other information, the LRN of the switch that serves the telephone number. When a telephone call is initiated, the initiating service provider's switch will query the LNP to check if the number has been ported (Sometimes referred to as an "LNP dip"). If the number has been ported, the LRN of the new switch is returned and the call is routed to that switch. If the number has not been ported, the call is routed based on the NPA-NXX prefix of the telephone number. If a subscriber decides to port their telephone number to different service provider, the new and old service providers work together with the NPAC to confirm the port request and update the corresponding region(s) LNP database with the LRN of the new switch that is serving the number.

History In 1996, the US Congress passed the Telecommunications Act of 1996 which made it easier for smaller companies to enter the telephony, broadcasting, and cable television markets. The new regulation provided for local number portability, which permitted the servicing of telephone numbers from other wire centers than those given by the NPA-NXX prefixes of each number. In practice, a subscriber can keep a telephone number when moving to another exchange area by a process called porting a telephone number. Every ported telephone number has an LRN assigned. Virginia-based Neustar was originally contracted with developing and maintaining the Number Portability Administration Center to support the implementation of local number portability. However, in July 2016, the FCC awarded the contract to administer NPAC to Ericsson subsidiary Telcordia Technologies, doing business as iconectiv, as the next Local Number Portability Administrator (LNPA), after 19 years of management by Neustar.

Worked examples

Example 1 — a first encounter with Location routing number

Start with the simplest possible case. Write down what Location routing number claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In mathematics, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Location routing number before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Location routing number ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Location routing number

In research: Location routing number appears in mathematics research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Location routing number in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Location routing number is common in secondary-school and first-year university syllabi. It links to neighbouring topics Telephone numbers, so understanding it makes those chapters shorter.
In everyday life: Look for Location routing number outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Location routing number in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Location routing number means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Location routing number out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Location routing number in simple terms?

Why does Location routing number matter?

Because it connects several mathematics ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Location routing number?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Location routing number.