Computer Science 9618 Communication and Internet Technologies

This set of vocabulary flashcards covers key terminology related to internet technologies, communication protocols, the TCP/IP suite, and data switching methods as outlined in the Computer Science 9618 Paper 3 curriculum.

Protocol

A known or accepted set of rules for the successful transmission and receipt of data between computers on different platforms.

POP $3/4$ (Post Office Protocol)

A "pull" protocol used for downloading or receiving email from an email server to a client.

HTTP (Hypertext Transfer Protocol)

A protocol responsible for the correct transfer of hypertext files and documents that make up web pages.

FTP (File Transfer Protocol)

A standard network protocol used to transfer, upload, download, rename, or delete files between a client and a server over a TCP-based network.

SMTP (Simple Mail Transfer Protocol)

A "push" protocol responsible for sending or transferring outgoing emails from a client to a mail server.

IMAP (Internet Message Access Protocol)

A protocol used for receiving emails that allows the server and client to stay in sync and enables access from different devices without deleting the original email.

Bit-Torrent Protocol

An application layer protocol used for peer-to-peer file sharing by splitting files into small pieces among many users.

TCP/IP Protocol Suite

A conceptual layered model consisting of $4$ layers (Application, Transport, Network, and Data Link) used for the transmission of data across the internet.

Application Layer

The top layer of the TCP/IP stack that contains all programs and protocols (like HTTP or SMTP) that exchange data.

Transport Layer

The layer responsible for breaking data into packets, adding sequence numbers to headers, managing flow control, and ensuring packets arrive without error.

Network Layer (Internet Layer)

The layer that uses Internet Protocol (IP) to manage data movement, routing, and identifying devices using IP addresses.

Link Layer (Data Link Layer)

The layer responsible for formatting data into frames for transmission over the physical medium and mapping IP addresses to MAC addresses.

MIME (Multipurpose Internet Mail Extension)

An extension required to send binary files, such as images and videos, that are not handled by the basic SMTP protocol.

TCP (Transmission Control Protocol)

A connection-oriented protocol that uses positive acknowledgment with re-transmission to ensure data packets arrive in the correct order.

IP (Internet Protocol)

A protocol that ensures the correct routing of packets by adding a header containing both recipient and sender IP addresses.

Packet Header

A component of a data packet used to store information about routing, IP version, packet size, and sequence numbers to ensure proper reconstruction.

Seed

A peer computer in a Bit-Torrent network that has $100\%$ of a file and is uploading downloaded content to others.

Swarm

The collective group of all connected peer computers that are sharing, uploading, or downloading parts of a specific torrent file.

Tracker

A central server that stores the IP addresses of peers in a swarm and tracks which parts of the file each computer possesses.

Leechers

Peers in a peer-to-peer network who download significantly more data than they upload, potentially impacting network performance.

Circuit Switching

A method of transmission where a dedicated circuit/path is established between sender and receiver before communication starts and is maintained for the duration of the call.

Packet Switching

A method where data is divided into packets that travel independently along potentially different routes to be reassembled at the destination.

Router

A device that examines packet headers for destination IP addresses and uses a routing table to decide the next hop for the packet.

Routing Table

A data table stored in a router that contains information such as the Subnet Mask, Routing Metric, Gateway, and Interface.