computer science

Presence and Instant Messaging

Presence and Instant Messaging 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 Presence and Instant Messaging rather than just read about it. In short: Presence and Instant Messaging (PRIM) was an early proposal to the IETF of a standard protocol for instant messaging. The abstract model was first published as a pair of IETF Request for Comments, RFC 2778 "A Model for Presence and Instant Messaging" and RFC 2779 "Instant Messaging / Presence Protocol Requirements" in February 2000, which was authored by Mark Day of SightPath (formerly of Lotus Development where hel…

Key takeaways

Presence and Instant Messaging 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 Presence and Instant Messaging to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Presence and Instant Messaging from memory before moving on to harder problems.

Reference excerpt

Presence and Instant Messaging (PRIM) was an early proposal to the IETF of a standard protocol for instant messaging. The abstract model was first published as a pair of IETF Request for Comments, RFC 2778 "A Model for Presence and Instant Messaging" and RFC 2779 "Instant Messaging / Presence Protocol Requirements" in February 2000, which was authored by Mark Day of SightPath (formerly of Lotus Development where helped develop IBM Lotus Sametime, now Chief Scientist at Riverbed Technology), Jonathan Rosenberg of dynamicsoft (now the Chief Technology Officer and Vice President of Collaboration at Cisco Systems) and Hiroyasu Sugano of Fujitsu Laboratories LtdLtd. No work has been done on it since 2001. Currently, SIP and its derivative SIMPLE (both of which Jonathan Rosenberg also co-authored or invented), and XMPP are being considered for use as instant messaging protocols. These were Informational RFCs, which describe the model and requirements for the way an Instant Messaging Protocol should work on the Internet. A new working group - the Instant Messaging and Presence Protocol group was established to develop the model in more detail.

See also Instant Messaging and Presence Protocol (IMPP) eXtensible Messaging and Presence Protocol (XMPP)

References

External links Presence and Instant Messaging Protocol (prim) WG - IETF Datatracker

Worked examples

Example 1 — a first encounter with Presence and Instant Messaging

Start with the simplest possible case. Write down what Presence and Instant Messaging 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 Presence and Instant Messaging 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 Presence and Instant Messaging 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 Presence and Instant Messaging

In research: Presence and Instant Messaging 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 Presence and Instant Messaging 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: Presence and Instant Messaging is common in secondary-school and first-year university syllabi. It links to neighbouring topics Instant messaging protocols, Internet stubs, Network software stubs, so understanding it makes those chapters shorter.
In everyday life: Look for Presence and Instant Messaging 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 Presence and Instant Messaging in 20 minutes

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

Frequently asked questions

What is Presence and Instant Messaging in simple terms?

Why does Presence and Instant Messaging 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 Presence and Instant Messaging?

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 Presence and Instant Messaging.