IB Computer Science HL · Year 2 · Lesson 41

IP addressing, media, packet switching and routing

Data transmission depends on addressing, media, packet movement and routing decisions from source to destination.

Paper 150 minutesA2.3.1 · A2.3.2 · A2.3.3 · A2.3.4
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Today’s targets

What you need to be able to do

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  • DescribeDifferent types of IP addressing
  • CompareTypes of media for data transmission
  • ExplainHow packet switching is used to send data across a network
  • ExplainHow static routing and dynamic routing move data across local area networks
A2.3.1A2.3.2A2.3.3A2.3.4
Paper 1 lensMatch the depth of every response to the command term. Previously learned content can move quickly, but retrieval must still be accurate.
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Retrieve

Rapid Recall Deck

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Say the answer aloud before flipping. Mark secure knowledge quickly and spend time on the gaps.

  • What is the main difference between IPv4 and IPv6?: IPv6 uses a much larger address space and a different address format than IPv4, helping address the shortage of IPv4 addresses.
  • What is the difference between public and private IP addresses?: Public addresses are routable on the public internet; private addresses are used within internal networks and are not directly routed across the public internet.
  • What is the difference between static and dynamic IP addressing?: A static address is deliberately kept fixed; a dynamic address is assigned and can change, commonly through DHCP.
  • What does network address translation (NAT) do?: It translates between private internal addresses and public addressing, allowing many internal devices to communicate through limited public addresses.
  • How do fibre optic, twisted pair, and wireless media differ?: Fibre offers high bandwidth and low interference over long distances; twisted pair is cheaper/easier but more susceptible to attenuation/interference; wireless offers mobility but can face interference, range, and security limits.
  • How does packet switching send data?: Data is divided into packets with routing/control information, packets can travel independently, and the data is reassembled at the destination.
  • How do static and dynamic routing differ?: Static routes are manually configured and predictable; dynamic routing adapts routes automatically, scaling better but using more resources and adding complexity.
  • Which factors matter when choosing static or dynamic routing?: Configuration and maintenance effort, complexity, resource usage, convergence, scalability, and network size.
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A2.3.1 + A2.3.2 · Learn

Core knowledge and application

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A2.3.1Describe

Different types of IP addressing

Data transmission depends on addressing, media, packet movement and routing decisions from source to destination.

Exam moveGive a detailed, accurate account of what happens or what something is like.
Required detail 1The distinction between IPv4 and IPv6 addressing
Required detail 2Compare public IP addresses and private IP addresses, and between static IP addresses and dynamic IP addresses
Required detail 3Role of network address translation (NAT) to minimize the use of IP addresses and to facilitate communication between private internal networks and the public internet

Explain it without notes

Describe: Different types of IP addressing in the context of a packet travelling from a student laptop to a cloud application.

  • The distinction between IPv4 and IPv6 addressing
  • Compare public IP addresses and private IP addresses, and between static IP addresses and dynamic IP addresses
  • Role of network address translation (NAT) to minimize the use of IP addresses and to facilitate communication between private internal networks and the public internet
A2.3.2Compare

Types of media for data transmission

Data transmission depends on addressing, media, packet movement and routing decisions from source to destination.

Exam moveMake direct, paired comparisons using the same criteria.
Required detail 1Wired transmission via fibre optic cables and twisted pair cables; wireless transmission
Required detail 2The advantages and disadvantages of these three types of data transmission
Required detail 3Factors to consider must include bandwidth, complexity of installation, cost, range, susceptibility to interference, attenuation, reliability, security

Explain it without notes

Compare: Types of media for data transmission in the context of a packet travelling from a student laptop to a cloud application.

  • Wired transmission via fibre optic cables and twisted pair cables; wireless transmission
  • The advantages and disadvantages of these three types of data transmission
  • Factors to consider must include bandwidth, complexity of installation, cost, range, susceptibility to interference, attenuation, reliability, security
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A2.3.3 + A2.3.4 · Learn

Core knowledge and application

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A2.3.3Explain

How packet switching is used to send data across a network

Data transmission depends on addressing, media, packet movement and routing decisions from source to destination.

Exam moveGive the mechanism or relationship and make the reasons/causes explicit.
Required detail 1The process of segmenting data into packets with a routing header attached, and independently transmitting control information, allowing the data to be reassembled at the destination
Required detail 2The role that switches and routers play in packet switching

Explain it without notes

Explain: How packet switching is used to send data across a network in the context of a packet travelling from a student laptop to a cloud application.

  • The process of segmenting data into packets with a routing header attached, and independently transmitting control information, allowing the data to be reassembled at the destination
  • The role that switches and routers play in packet switching
A2.3.4Explain

How static routing and dynamic routing move data across local area networks

Data transmission depends on addressing, media, packet movement and routing decisions from source to destination.

Exam moveGive the mechanism or relationship and make the reasons/causes explicit.
Required detail 1The process of static routing, and its advantages and disadvantages
Required detail 2The process of dynamic routing, and its advantages and disadvantages (explanation of a specific routing protocol is not required)
Required detail 3Factors to consider must include configuration, maintenance, complexity, resource usage, convergence, scalability, network size

Explain it without notes

Explain: How static routing and dynamic routing move data across local area networks in the context of a packet travelling from a student laptop to a cloud application.

  • The process of static routing, and its advantages and disadvantages
  • The process of dynamic routing, and its advantages and disadvantages (explanation of a specific routing protocol is not required)
  • Factors to consider must include configuration, maintenance, complexity, resource usage, convergence, scalability, network size
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Worked model · A2.3.1–A2.3.4

Addressing, packet switching and routing

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Private IPv4 host
→
NAT router
→
Public internet

Packet switching

Split data into packets and attach control/routing information.
Packets may travel independently through switches/routers.
The destination uses control information to reassemble the original data.
Routing choice
Static
Dynamic
Configuration
manual routes
routes learned/updated automatically
Resource use
low ongoing overhead
uses processing/bandwidth for route updates
Best fit
small/stable network
larger/changing network
Media decisionCompare fibre, twisted pair and wireless using bandwidth, installation complexity, cost, range, interference, attenuation, reliability and security.
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Apply

Transfer to a new scenario

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ScenarioA packet travelling from a student laptop to a cloud application needs a design or technical decision related to today’s topic. Explain what matters and why.
  • The distinction between IPv4 and IPv6 addressing
  • Compare public IP addresses and private IP addresses, and between static IP addresses and dynamic IP addresses
  • Wired transmission via fibre optic cables and twisted pair cables; wireless transmission
  • The advantages and disadvantages of these three types of data transmission
  • The process of segmenting data into packets with a routing header attached, and independently transmitting control information, allowing the data to be reassembled at the destination
  • The role that switches and routers play in packet switching
  • The process of static routing, and its advantages and disadvantages
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Exam lens

Paper 1 practice

8 / 9
Build the response before checking notesUse precise terminology and match the required depth.
  1. Describe: Different types of IP addressing in the context of a packet travelling from a student laptop to a cloud application.
  2. Compare: Types of media for data transmission in the context of a packet travelling from a student laptop to a cloud application.
  3. Explain: How packet switching is used to send data across a network in the context of a packet travelling from a student laptop to a cloud application.
Self-checkAnswer the exact command term. For explain, include mechanism/reason; for compare, pair criteria; for discuss/evaluate/justify, build supported reasoning and a conclusion.
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Homework

Finish the learning cycle

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IA — main task

Complete Criterion E and final IA quality checks. Evaluate the product against success criteria and propose specific, feasible improvements.

Syllabus — short

Complete a short Paper 1 retrieval task; keep the IA as the main workload.

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End of Lesson 41.