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9618Paper 1 · Theory Fundamentals§2.1

2. Communication

Networks (LAN/WAN, client–server, peer-to-peer, thin and thick clients), topologies, cloud computing, wired and wireless media, LAN hardware, Ethernet, bit streaming, the internet's infrastructure, IP addressing, URLs and DNS.

Statometer71CoreNext Paper 176%
Marks a paper11.5 · 15%Rank#8 of 12 · #6 on P1Trend · last 12Oct/Nov 24 · 11: 0 marksOct/Nov 24 · 12: 0 marksOct/Nov 24 · 13: 14 marksMay/Jun 25 · 11: 13 marksMay/Jun 25 · 12: 19 marksMay/Jun 25 · 13: 15 marksOct/Nov 25 · 11: 14 marksOct/Nov 25 · 12: 23 marksOct/Nov 25 · 13: 7 marksMay/Jun 26 · 11: 13 marksMay/Jun 26 · 12: 0 marksMay/Jun 26 · 13: 0 marks
8 in 10 chance in the next paper

Everything for this topic — study hub

AS Level · 9618 · Paper 1

Statometer — what 33 real papers say about this topic and each of its 3 syllabus bullets

Core · #8 of 12 in AS Level · recomputed with every new session

71CORE
Core#8 of 12 in AS Level#6 on Paper 1 Steady

A regular, well-paid topic — you cannot afford a gap here.

Next Paper 1
76%
8 in 10 chance it is set
Marks a paper
11.5 / 75
15% of Paper 1 · fair share 13%
Appeared in
28 / 33
Paper 1 sittings 20212026
Last set
May/Jun 2026
9618/11 · Q7 · 13 marks · 11-series streak
Marks in each of the last 12 Paper 1 sittingsOct/Nov 24May/Jun 26
Oct/Nov 24 · 11: 0 marksOct/Nov 24 · 12: 0 marksOct/Nov 24 · 13: 14 marksMay/Jun 25 · 11: 13 marksMay/Jun 25 · 12: 19 marksMay/Jun 25 · 13: 15 marksOct/Nov 25 · 11: 14 marksOct/Nov 25 · 12: 23 marksOct/Nov 25 · 13: 7 marksMay/Jun 26 · 11: 13 marksMay/Jun 26 · 12: 0 marksMay/Jun 26 · 13: 0 marks

What the papers say

  • Set in 28 of 33 Paper 1 sittings — about 8 papers in 10.
  • Worth about 11.5 marks a paper (15% of Paper 1).
  • Last set May/Jun 2026 · 9618/11 · Q7 for 13 marks — in the most recent series.
  • Set in each of the last 11 series without a miss.
  • Steady at around 11 marks a paper year on year.
  • Lives on “Describe” and “Complete” — 87% of its questions: full sentences with a reason, not one-word answers.
  • 55% of its questions involve a diagram, table or figure — practise with pen and paper.
  • Most of its marks (69%) come in extended questions of 12+ marks — plan the answer before writing.
  • Its biggest question so far: 20 marks (May/Jun 2023 · 9618/11 · Q4).
  • Inside the topic, §2.1 Networks carries the most marks (44%) and §2.1 The internet the least (19%).
  • It is examined almost entirely as AO1 (Knowledge & understanding, 85%) — definitions and descriptions in syllabus words score.
  • The examiner has commented on 22 of its questions — read “What the examiner said” before you practise.

Command words

Share of questions using the word (a question can use several). What each wants →

Question shapes

  • ≤ 6 mk3
  • 7–9 mk5
  • 10–12 mk6
  • 13–15 mk10
  • 16+ mk7

Average 12.4 marks a question · 55% with a figure or table · 39% with code · biggest 20 marks

Assessment objectives — how it is examined

Every part of every current-syllabus question filed under Cambridge's AO1 / AO2 / AO3 (from its command word and what it asks you to do), so you know whether this topic pays for definitions, for applying, or for judging and building.

  • AO1 Knowledge & understanding
  • AO2 Apply & analyse
  • AO3 Design, program & evaluate

Paper 1 as a whole

Paper 1SyllabusMeasured
AO1 Knowledge & understanding60%68%
AO2 Apply & analyse40%32%
AO3 Design, program & evaluate0%0%

Syllabus = Cambridge's grid; measured = the bank's current-syllabus papers.

Inside the topic — every syllabus bullet, measured

Each part of each question is filed under the bullet it examines; the numbers are per Paper 1 sitting, exactly like the topic's. Open a bullet for its own Statometer.

  • 2.1Networks#9 of 25 on Paper 1Core · 6763% next paper4 marks24/33 sittings May/Jun 2026

    A regular earner inside the topic — most papers touch it.Syllabus: networking devices; LAN vs WAN; client-server vs peer-to-peer; thin vs thick clients; bus, star, mesh and hybrid topologies; public and private cloud computing

    Next Paper 1
    63%
    6 in 10
    Marks a paper
    4
    5% of the paper · 44% of the topic
    Asked in
    24 / 33
    Paper 1 sittings · 27 questions
    Last asked
    May/Jun 2026
    9618/11 · Q7 · 6 marks · 11-series streak
    • Asked in 24 of 33 Paper 1 sittings — about 7 papers in 10.
    • About 4 marks a paper (5% of Paper 1; 44% of the topic's marks across its 3 bullets).
    • Last asked May/Jun 2026 · 9618/11 · Q7 (6 marks) — in the most recent series.
    • Asked in each of the last 11 series.
    • Usually “Describe” or “Complete”: full sentences with a reason, not one-word answers.
    • Biggest chunk of marks so far: 12 in May/Jun 2025 · 9618/12 · Q6.
    • It is examined almost entirely as AO1 (Knowledge & understanding, 88%) — definitions and descriptions in syllabus words score.
    Last 12 sittings Steady
    Oct/Nov 24 · 11: 0 marksOct/Nov 24 · 12: 0 marksOct/Nov 24 · 13: 7 marksMay/Jun 25 · 11: 0 marksMay/Jun 25 · 12: 12 marksMay/Jun 25 · 13: 3 marksOct/Nov 25 · 11: 0 marksOct/Nov 25 · 12: 11 marksOct/Nov 25 · 13: 2 marksMay/Jun 26 · 11: 6 marksMay/Jun 26 · 12: 0 marksMay/Jun 26 · 13: 0 marks

    Assessment objectives

    • AO1 Knowledge & understanding
    • AO2 Apply & analyse
    • AO3 Design, program & evaluate
    • Describe78%
    • Complete52%
    • Explain48%
    • State44%
  • 2.1Media and LAN hardware#11 of 25 on Paper 1Core · 6365% next paper3.6 marks23/33 sittings May/Jun 2026

    A regular earner inside the topic — most papers touch it.Syllabus: wired (copper, fibre) vs wireless (radio, microwave, satellite); switch, server, NIC/WNIC, WAP, bridge, repeater; the router; Ethernet and CSMA/CD; bit streaming

    Next Paper 1
    65%
    6 in 10
    Marks a paper
    3.6
    5% of the paper · 37% of the topic
    Asked in
    23 / 33
    Paper 1 sittings · 24 questions
    Last asked
    May/Jun 2026
    9618/11 · Q7 · 6 marks · 11-series streak
    • Asked in 23 of 33 Paper 1 sittings — about 7 papers in 10.
    • About 3.6 marks a paper (5% of Paper 1; 37% of the topic's marks across its 3 bullets).
    • Last asked May/Jun 2026 · 9618/11 · Q7 (6 marks) — in the most recent series.
    • Asked in each of the last 11 series.
    • Usually “Describe” or “Complete”: full sentences with a reason, not one-word answers.
    • Biggest chunk of marks so far: 11 in May/Jun 2025 · 9618/11 · Q2.
    • It is examined almost entirely as AO1 (Knowledge & understanding, 82%) — definitions and descriptions in syllabus words score.
    Last 12 sittings Steady
    Oct/Nov 24 · 11: 0 marksOct/Nov 24 · 12: 0 marksOct/Nov 24 · 13: 6 marksMay/Jun 25 · 11: 11 marksMay/Jun 25 · 12: 4 marksMay/Jun 25 · 13: 8 marksOct/Nov 25 · 11: 0 marksOct/Nov 25 · 12: 6 marksOct/Nov 25 · 13: 2 marksMay/Jun 26 · 11: 6 marksMay/Jun 26 · 12: 0 marksMay/Jun 26 · 13: 0 marks

    Assessment objectives

    • AO1 Knowledge & understanding
    • AO2 Apply & analyse
    • AO3 Design, program & evaluate
    • Describe83%
    • Complete58%
    • Explain50%
    • Identify46%
  • 2.1The internet#19 of 25 on Paper 1Regular · 3852% next paper1.7 marks17/33 sittings May/Jun 2026

    Set most sessions for a few marks; know the definition and one example.Syllabus: WWW vs internet; modems, PSTN, dedicated lines and cell networks; IPv4/IPv6, subnetting, public/private and static/dynamic addresses; URLs and DNS

    Next Paper 1
    52%
    5 in 10
    Marks a paper
    1.7
    2% of the paper · 19% of the topic
    Asked in
    17 / 33
    Paper 1 sittings · 17 questions
    Last asked
    May/Jun 2026
    9618/11 · Q7 · 1 marks · 8-series streak
    • Asked in 17 of 33 Paper 1 sittings — about 5 papers in 10.
    • About 1.7 marks a paper (2% of Paper 1; 19% of the topic's marks across its 3 bullets).
    • Last asked May/Jun 2026 · 9618/11 · Q7 (1 marks) — in the most recent series.
    • Asked in each of the last 8 series.
    • Usually “Describe” or “Complete”: full sentences with a reason, not one-word answers.
    • Biggest chunk of marks so far: 8 in Oct/Nov 2025 · 9618/11 · Q7.
    • It is examined almost entirely as AO1 (Knowledge & understanding, 90%) — definitions and descriptions in syllabus words score.
    Last 12 sittings Steady
    Oct/Nov 24 · 11: 0 marksOct/Nov 24 · 12: 0 marksOct/Nov 24 · 13: 1 marksMay/Jun 25 · 11: 2 marksMay/Jun 25 · 12: 3 marksMay/Jun 25 · 13: 4 marksOct/Nov 25 · 11: 8 marksOct/Nov 25 · 12: 0 marksOct/Nov 25 · 13: 0 marksMay/Jun 26 · 11: 1 marksMay/Jun 26 · 12: 0 marksMay/Jun 26 · 13: 0 marks

    Assessment objectives

    • AO1 Knowledge & understanding
    • AO2 Apply & analyse
    • AO3 Design, program & evaluate
    • Describe71%
    • Complete65%
    • Explain65%
    • Identify47%

18% of the topic's marks sit in question parts that belong to another topic (scenario questions cross sections) or that no bullet claims; they count for the topic, not for a bullet.

Marks a paper, year by year

212223242526

By exam series

  • May/Jun15/18 · 13.1 mk
  • Oct/Nov13/15 · 9.9 mk

What you need to know3syllabus §2.1

  1. 2.1Networksnetworking devices; LAN vs WAN; client-server vs peer-to-peer; thin vs thick clients; bus, star, mesh and hybrid topologies; public and private cloud computing
  2. 2.1Media and LAN hardwarewired (copper, fibre) vs wireless (radio, microwave, satellite); switch, server, NIC/WNIC, WAP, bridge, repeater; the router; Ethernet and CSMA/CD; bit streaming
  3. 2.1The internetWWW vs internet; modems, PSTN, dedicated lines and cell networks; IPv4/IPv6, subnetting, public/private and static/dynamic addresses; URLs and DNS

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Infographics2draw these the way the examiner expects · download as PNG

Network topologiesKnow one advantage and one disadvantage of each — and where a single fault stops the network.BUSN1N2N3N4One cable (terminated). Cheap.Collisions; break = whole network down.STARN1N2N3N4N5SWCentral switch. One cable fault isolated.Switch fails = all down; more cable.MESHN1N2N3N4N5Every node linked. Redundant paths.Expensive; complex to manage.Hybrid = mixture (e.g. star-bus). Wireless networks form a star around the access point.Client-server vs peer-to-peer is a separate question from topology.cswithzak.com

Network topologies

AS
IP addressing, subnets & DNSIPv4 = 32 bits shown as four denary octets. IPv6 = 128 bits shown as eight hexadecimal groups. DNS mapsnames to addresses.IPv4192.168.1.10110000001010100000000001000010104 octets × 8 bits = 32 bits · each octet 0–255 · ≈ 4.3 billion addresses (2³²) — not enough, hence IPv6 and private ranges.Subnet mask 255.255.255.01s mark the network part, 0s the host part → network ID 192.168.1.0, host 10. Same network ID = same subnet = no router needed.CIDR shorthand: 192.168.1.10/24 (24 network bits). Subnetting splits one network into smaller ones for security and less traffic.IPv62001:0db8:85a3:0000:0000:8a2e:0370:73348 groups × 16 bits = 128 bits, hex. Drop leading zeros; one run of zero groups becomes :: → 2001:db8:85a3::8a2e:370:7334TypeMeaningPublicunique on the internet, allocated by the ISPPrivate10.x · 172.16–31.x · 192.168.x (LAN only, via NAT)Staticfixed — servers, printersDynamicassigned by DHCP each sessionDNS — Domain Name SystemHierarchy of servers: root → .com → cswithzak.comBrowser asks the local DNS server; if unknown it asks upthe chain; the IP is returned and cached for next time.URL = protocol :// domain name / pathcswithzak.com

IP addressing, subnets & DNS

AS

Browse all infographics →

Key terms16use these exact words in the exam

LANWANclient-serverpeer-to-peerthin clientthick clienttopologycloudEthernetCSMA/CDbit streamingIPv4IPv6subnetDNSURL

Dotted terms are defined in the glossary.

Code help1referenced to the Cambridge pseudocode guide

Validate an IPv4 address

pseudocode §5.5 MID / LENGTH Run in Playground
DECLARE IP, Part : STRING
DECLARE i, Dots, Val : INTEGER
DECLARE OK : BOOLEAN
IP "192.168.1.254"
OK TRUE
Dots 0
Part ""
FOR i 1 TO LENGTH(IP) + 1
IF i > LENGTH(IP) OR MID(IP, i, 1) = "." THEN
Val STR_TO_NUM(Part)
IF Val < 0 OR Val > 255 THEN
OK FALSE
ENDIF
Part ""
Dots Dots + 1
ELSE
Part Part & MID(IP, i, 1)
ENDIF
NEXT i
OUTPUT IP, " valid: ", OK AND Dots = 4

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