computer science

Ntop

Ntop is a computer science 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 Ntop rather than just read about it. In short: ntop is computer software that probes a computer network to show network use in a way similar to what the program top does for processes. Not to be confused with the CAD/CAE software nTop (formerly nTopology).

Key takeaways

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

Reference excerpt

ntop is computer software that probes a computer network to show network use in a way similar to what the program top does for processes. Not to be confused with the CAD/CAE software nTop (formerly nTopology).

Software In interactive mode, it displays the network status on the user's terminal. In Web mode, it acts as a web server, creating a HTML dump of the network status. It supports a NetFlow-sFlow emitter-collector, a Hypertext Transfer Protocol (HTTP) based client interface for creating ntop-centric monitoring applications, and RRDtool (RRD) for persistently storing traffic statistics. ntop is available for both Unix and Win32-based platforms. It has been developed by Luca Deri, an Italian research scientist and network manager at University of Pisa. Common usage on a Linux system is to start the ntop daemon (/etc/init.d/ntopd start), then one can use the web interface to ntop via visiting http://127.0.0.1:3000 provided the loopback device has been started (/etc/init.d/net.lo start) and the listening port for ntop is 3000 (look out for the -w option in grep ntop).

Worked examples

Example 1 — a first encounter with Ntop

Start with the simplest possible case. Write down what Ntop claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In computer science, 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 Ntop 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 Ntop 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 Ntop

In research: Ntop appears in computer science 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 Ntop 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: Ntop is common in secondary-school and first-year university syllabi. It links to neighbouring topics Linux security software, Network analyzers, Unix network-related software, so understanding it makes those chapters shorter.
In everyday life: Look for Ntop 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 Ntop in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Ntop 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 Ntop out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Ntop in simple terms?

Why does Ntop matter?

Because it connects several computer science 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 Ntop?

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 Ntop.