computer science

OSIP

OSIP 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 OSIP rather than just read about it. In short: oSIP is a free software library for VoIP applications implementing lower layers of Session Initiation Protocol (SIP). The library includes the minimal codebase required by any SIP application and offers enough flexibility to implement any SIP extension or behavior.

Key takeaways

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

Reference excerpt

oSIP is a free software library for VoIP applications implementing lower layers of Session Initiation Protocol (SIP). The library includes the minimal codebase required by any SIP application and offers enough flexibility to implement any SIP extension or behavior. Started in September 2000 and published in April 2001, oSIP is among the oldest SIP free software stack still being developed and maintained. The project was made part of the GNU Project as GNU oSIP in 2002.

Software using oSIP eXosip, the "eXtended osip" library. An extension of oSIP for softphone implementation written by Aymeric Moizard. GNU SIP Witch

Software that used oSIP Linphone. Linphone has been the first project based on oSIP and eXosip. Jami (software). FreeSWITCH.

Usage in academic research Yang, Yang (2007). SIP over Client Initiated Connections (Thesis). Helsinki University of Technology. Archived from the original on 2016-04-02. Retrieved 2014-01-29. Burgy, Laurent (2008). Approche langage au développement du support protocolaire d'applications réseaux (PDF) (Thesis). University of Bordeaux 1. Dai, H B (2008). Theory and Implementation of VoIP Based SIP Protocol (Thesis). Chinese Geology University (Beijing). Wang, H (2008). The Design and Development of IP Phone's Added-Vale Services Based on SIP Protocol (Thesis). Beijing University of Posts and Telecommunications. SongYuNa (2009). The Research and Development of Embedded VoIP Gateway Based on IXP425 (Thesis). Tianjin University. Archived from the original on 2014-02-03. Retrieved 2014-01-29. Zhang, Z H (2010). Research And Implementation Of IP Phone Terminal Based On SIP Protocol (Thesis).

Illustrations

Worked examples

Example 1 — a first encounter with OSIP

Start with the simplest possible case. Write down what OSIP 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 OSIP 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 OSIP 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 OSIP

In research: OSIP 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 OSIP 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: OSIP is common in secondary-school and first-year university syllabi. It links to neighbouring topics Android (operating system) software, BlackBerry software, Communication software, so understanding it makes those chapters shorter.
In everyday life: Look for OSIP 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 OSIP in 20 minutes

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

Frequently asked questions

What is OSIP in simple terms?

Why does OSIP 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 OSIP?

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 OSIP.