NEB Class 12 • Computer Science • Networking • Concept Guide

OSI Model, TCP-IP & IP Addressing: NEB Class 12 Computer Guide

Master OSI Model, TCP-IP and IP Addressing through clear concepts, representations, a reliable answer method and exam-focused practice.

ConceptsWorked reasoningNEB practice

Core concept

What OSI Model, TCP-IP and IP Addressing means physically

Layered models separate communication responsibilities. OSI has seven conceptual layers; TCP/IP groups practical Internet functions. IP addresses identify interfaces for routed delivery, while ports identify application endpoints.

Encapsulation adds headers as data moves down layers and removes them upward. IPv4 has 32 bits; a prefix such as /24 separates network and host portions under the mask.

The institutional reference gives the wider physical model; the CDC curriculum determines the NEB boundary.

Worked checkpoint with interpretation

For 192.168.10.34/24, the network is 192.168.10.0 and the typical host range lies within that subnet excluding reserved network and broadcast addresses.

Do not stop at the number. State what the sign, ratio, spacing, frequency or direction means. A common error is Treating OSI and TCP/IP as identical layer counts, confusing MAC with IP or port, using the network address as a host, or guessing subnet range without applying the mask.

NEB answer method

Model → evidence → equation → check

First identify the system and what the question asks. Label the diagram, apparatus or reaction with SI quantities, then state the principle before selecting an equation. Solve symbolically where possible and check units, limiting cases and chemical or physical meaning.

Stage	Question	Evidence
Model	What is idealised?	Assumption stated
Representation	Which diagram fits?	Labels or balanced equation
Calculation	Which relation follows?	Symbols then SI values
Evaluation	Does it make sense?	Unit, sign and trend check

Make the idea concrete in Nepal

Connect the model to a school laboratory, household technology, health, environment, energy or local material. The example should clarify the science rather than merely mention a place. Compare a prediction with an observation and record uncertainty.

Review the NEB Class 12 Computer Science revision roadmap and the complete Computer Science guide. For online or physical tuition, call 9846662070.

Frequently asked questions

Questions students ask about OSI Model, TCP-IP and IP Addressing

What is the central idea of OSI Model, TCP-IP and IP Addressing?+

Which equation should I remember?+

Encapsulation adds headers as data moves down layers and removes them upward. IPv4 has 32 bits; a prefix such as /24 separates network and host portions under the mask.

How should I begin a numerical?+

Draw the situation, list known quantities in SI units, choose the governing relation symbolically, substitute once and finish with a unit and reasonableness check.

What is a common exam mistake?+

Treating OSI and TCP/IP as identical layer counts, confusing MAC with IP or port, using the network address as a host, or guessing subnet range without applying the mask.

How can I practise this topic?+

Alternate one concept explanation, one diagram and two numericals. Revisit errors after a day instead of only rereading the solution.

Where can I get tuition support?+

For online or physical KTM Tuition classes, call 9846662070. After Grade 12, the MKS Education panel below gives preparation and pre-counselling contacts.

References and next steps

Scope checked against CDC Nepal; concept support from an institutional reference and OpenStax Science. Continue with the OSI Model, TCP-IP and IP Addressing cluster.

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