Computer Networks, Connections and Protocols | OCR GCSE Computer Science (J277)

Computer Networks, Connections and Protocols

99 questions
6 subtopics
J277/01
J277/01

Computer Networks, Connections and Protocols is examined in J277/01, Computer systems.

It covers LANs, WANs and network performance, client-server and peer-to-peer networks, network hardware, DNS, hosting and the cloud, star and mesh topologies, wired and wireless connections, IP and MAC addresses and protocols, standards and layers.

Sample questions from Computer Networks, Connections and Protocols

Answer each one closed book first, then open the answer.

LANs, WANs and network performance

Why would a bank with branches all over the country use a WAN?

Show the answer
A WAN links every branch to the bank's central systems. Staff in any branch can then reach the same customer records and accounts.
LANs, WANs and network performance

How can distance from a wireless access point affect a device's connection?

Show the answer
A wireless signal weakens with distance and when it passes through walls. A weaker signal lowers the data rate and causes more data to be resent.
Client-server and peer-to-peer networks

Apart from web and file servers, name two types of server and what each provides.

Show the answer
A print server manages a queue of jobs sent to shared printers. A mail server stores, sends and receives email for its users.
Client-server and peer-to-peer networks

Give two disadvantages of a peer-to-peer network.

Show the answer
Files are spread across many machines, so backups and security are hard to manage. A file becomes unavailable when the computer holding it is switched off.
Network hardware, DNS, hosting and the cloud

What is a wireless access point (WAP)?

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A wireless access point lets wireless devices join a wired network. A WAP sends and receives radio signals and passes the data on to the wired network.
Network hardware, DNS, hosting and the cloud

Describe how DNS is used when a URL is typed into a web browser.

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The browser sends the domain name to a DNS server. The DNS server looks up the matching IP address and returns it. The browser then requests the page from that IP address.
Star and mesh topologies

Give two disadvantages of a star topology.

Show the answer
A star needs a lot of cable because each device has its own link to the centre. The whole network stops if the central switch fails.
Star and mesh topologies

Give two disadvantages of a wired mesh topology.

Show the answer
A wired mesh needs a great deal of cabling, which makes it expensive. A mesh is complex to set up and maintain as more devices are added.

The 6 subtopics

One subtopic is one session. Work down the list.

Subtopic	What it covers	Questions
LANs, WANs and network performance	LANs and WANs, bandwidth, and how the number of devices, transmission media, distance and interference affect performance, with worked transfer-time and shared-bandwidth calculations.	15
Client-server and peer-to-peer networks	Servers and clients, web, file, print and mail servers, peer-to-peer networks, the advantages and disadvantages of each model, and choosing one for a home or a school.	16
Network hardware, DNS, hosting and the cloud	NICs, switches, routers and wireless access points, transmission media, the internet, how DNS turns a URL into an IP address, web hosting, and the cloud.	17
Star and mesh topologies	Star and mesh topologies, what happens when a cable or switch fails, full and partial mesh, wireless mesh networks, and choosing a topology for an office or hospital.	15
Wired and wireless connections, IP and MAC addresses	Ethernet, Wi-Fi and Bluetooth, wired against wireless connections, encryption on wireless networks, IPv4 and IPv6 addresses, and how MAC addresses differ from IP addresses.	18
Protocols, standards and layers	Standards and protocols, TCP and IP, HTTP and HTTPS, FTP, SMTP, POP and IMAP, choosing an email protocol, and why networking is organised into layers.	18

Computer Networks, Connections and Protocols is 99 of the 740 questions in the guide.Get the guide, £7

How the guide is worked

Answering a question from memory stores it far better than reading the answer again. The guide runs that as a fixed procedure on one subtopic at a time, about twenty minutes a session.

Step 1 · Closed book
Cover the answers. Work through one subtopic and write down what you can. Leave blanks where you have nothing.
Step 2 · Open book
Go back to the top. Read each printed answer and write it out in full, including the ones you had right.
Step 3 · Closed book again
Same questions, same order, from memory. The gap between pass one and pass three is the session result.

Read the full method, the return schedule and the research behind it.