Fundamentals of Communication and Networking

What Fundamentals of Communication and Networking covers

Serial and parallel transmission, networks and their topologies, wireless, the TCP/IP stack, application layer protocols, the client server model and thin-client computing. Examined on Paper 2.

The 15 subtopics

Each one has its own page.

• Communication methodsRecall questions on serial against parallel transmission, why serial wins over distance, and synchronous against asynchronous transmission and their overheads.Open →
• Communication basicsRecall questions on baud rate, bit rate, bandwidth, latency and protocol, and on why the bit rate can exceed the baud rate.Open →
• Network Topology and Types of NetworkingRecall questions on physical star and logical bus topologies and their operation, and on peer-to-peer and client-server networking.Open →
• Wireless networkingRecall questions on the adapter and the access point, the SSID, why wireless needs encryption when wired does not, and how far hiding the SSID actually protects.Open →
• The Internet and Packet SwitchingRecall questions on the structure of the Internet, how packet switching works, its advantages and the role of a router.Open →
• Routing, URLs and Domain NamesRecall questions on how a router chooses a route, the parts of a URL and what a fully qualified domain name is.Open →
• Firewalls, Worms, Trojans and VirusesRecall questions on firewalls, packet filtering, proxy servers and stateful inspection, how viruses, worms and trojans differ, and how code quality, monitoring and protection address them.Open →
• Encryption, Digital Signatures and CertificatesRecall questions on symmetric and asymmetric encryption and key exchange, how a digital signature is created and verified, which key does what, and what digital certificates contain and why they are needed.Open →
• TCP/IPRecall questions on the four layers and what each does, which addresses change at each hop, sockets and port numbers, and why both MAC and IP addresses are needed.Open →
• Standard application layer protocolsRecall questions on FTP, HTTP, HTTPS, POP3, SMTP and SSH, which of them expose data to an eavesdropper, and how anonymous FTP access differs.Open →
• IP Address Structure and Subnet MaskingRecall questions on how an address is structured, why it splits into network and host parts, and how a subnet mask is applied.Open →
• IP Standards and Public and Private AddressesRecall questions on the two current standards, the format of each, how many addresses each provides and the private address ranges.Open →
• DHCP and Network Address TranslationRecall questions on the purpose of DHCP and how it works, what else the server supplies, why addresses are leased, and what NAT does.Open →
• Client server modelRecall questions on request-response, why Websockets are used and what full-duplex buys you, CRUD, REST, and JSON against XML.Open →
• Thin- versus thick-client computingRecall questions on where the processing sits in each model, the hidden costs of cheap client hardware, and which model survives a network failure.Open →

What you need to know

Answer each one before you reveal it.

Take Fundamentals of Communication and Networking further

The same content, four other ways.

Commonly confused

Pairs that lose marks when they are blurred together.

• Serial transmission vs Parallel transmission

  Serial transmission: bits travel sequentially along one channel. Parallel transmission: several bits travel simultaneously along separate wires.

• Peer-to-peer network vs Client-server network

  Peer-to-peer network: hosts have equal status and share resources directly. Client-server network: designated hosts request services from dedicated providers.

• Public IP address vs Private IP address

  Public IP address: a globally unique address routable across the Internet. Private IP address: an address reserved for internal networks and not globally routable.

Questions from this topic

Each one with the model answer underneath.

1. 1

   Define serial transmission.

   Model answer

   Serial transmission sends data one bit at a time, in sequence, down a single wire or channel. The bits arrive one after another and are reassembled into bytes at the receiving end.

2. 2

   Define parallel transmission.

   Model answer

   Parallel transmission sends several bits at the same time, each bit travelling down its own separate wire in a multi-wire link. A group of bits (for example eight) is therefore transmitted simultaneously rather than one after another.

3. 3

   Why is serial transmission preferred over parallel for anything but very short distances?

   Model answer

   Three reasons. First, skew: the wires in a parallel link are never electrically identical, so bits sent together arrive at slightly different times, and over distance the skew grows until the bits of one group overlap those of the next. Second, crosstalk: current in one wire induces interference in its neighbours, and this worsens as the wires get longer and as the data rate rises. Third, cost and bulk: a single-conductor cable is cheaper, thinner and more flexible than a multi-wire ribbon. Serial links can therefore be clocked much faster over distance, which more than offsets sending only one bit at a time.

4. 4

   Parallel transmission sends eight bits at once and serial only one. So why is a serial link often faster in practice?

   Model answer

   Because the achievable clock rate matters more than the number of wires. A parallel link is limited by skew and crosstalk, so its clock must be kept low enough that all eight bits still arrive within the same window. A serial link has neither problem, so it can be clocked at a far higher frequency. A single wire running many times faster beats eight wires running slowly.

5. 5

   Where is parallel transmission still a sensible choice?

   Model answer

   Over very short distances inside a computer, where skew and crosstalk have too little cable length to build up — for example the internal buses of a processor, or the connections between a processor and memory on a motherboard.

6. 6

   Define synchronous data transmission.

   Model answer

   In synchronous transmission the sender and receiver are kept in step by a shared clock signal, usually carried on a separate line or recovered from the data stream itself. Data is sent as a continuous stream of bits timed against that clock, with no gaps between characters, and the receiver samples the line at each clock tick.

What is inside Levo

Six ways to work the same material.

Fundamentals of Communication and Networking revision questions

What does Fundamentals of Communication and Networking cover in AQA A-Level Computer Science?

15 subtopics: communication methods, communication basics, network topology and types of networking, wireless networking, the internet and packet switching, routing, urls and domain names, firewalls, worms, trojans and viruses, encryption, digital signatures and certificates, tcp/ip, standard application layer protocols, ip address structure and subnet masking, ip standards and public and private addresses, dhcp and network address translation, client server model and thin- versus thick-client computing. Each one has its own page with questions and model answers.

How is Fundamentals of Communication and Networking organised?

By the AQA 7517 specification, subtopic by subtopic, so it matches the order you are taught it in.