COE768: Computer Networks (Week 1 and 2)

Computer Network

A system that interconnects computing devices for data exchanges and communication.

Local Area Network (LAN)

A network that links computing systems within a local area.

Home Network

A LAN that links devices within a single home.

Metropolitan Area Network (MAN)

A network that links computing systems across entire cities.

Wide Area Network (WAN)

A network that links computing systems across entire countries and/or the world.

Internet

A WAN that is a network of networks consisting of LANs, MANs, and WANs.

Node

A general term for network-connected devices.

Reliability

The ability to recover from errors and handle device failures in a network.

Resource Allocation

The management of shared resources in a network to avoid collision problems.

Flow Control

The regulation of data transmission to prevent data overflow in a network.

Host

Any device connected to a computer network.

Server

A high-powered computer used as a central repository for data and programs shared by users within a network.

Client

A computer running a program that requests services from a server.

Link

A path that connects devices in a network for data transmission.

Router

A device that relays messages from one device to another in a network.

Switch

A device used to connect devices within a network.

Half Duplex

A mode of communication in which both parties can communicate with each other but not simultaneously.

Full Duplex

A mode of communication in which both parties can communicate in each direction simultaneously.

Simplex

A mode of communication in which communication is only possible in one direction.

Software Components

A wide range of software relating to the operations, design, monitoring, and implementation of computer networks.

Protocol

A pre-existing agreement that defines the format and order of message exchanges between communicating entities in a network.

Message

Any data transmitted over a network that is intended for computer interpretation.

Network Topology

The way nodes are connected in a network, affecting various aspects such as budget, performance, and security.

Point-to-Point Topology

A network topology in which each device is individually connected to a central connection point.

Bus Topology

A network topology in which every node is connected to a single bus.

Star Topology

A network topology in which all nodes are individually connected to a central switch.

Ring Topology

A network topology in which data travels in one direction from the source until it reaches its destination.

Tree Topology

A network topology in which multiple star topologies are connected in a large-scale bus topology.

Mesh Topology

A network topology in which devices are interconnected with each other device in the local network.

Hybrid Topology

A network topology that is a combination of two or more distinct network topologies.

Wireless Network

A network that uses wireless communication for data transmission.

Wireless Local Area Network (WLAN)

A wireless network used in limited areas such as homes, schools, and labs.

Personal Area Network (PAN)

A short-range network designed for peripheral devices without being connected to the internet.

Wired Network

A network that uses physical cables for data transmission.

Classic Ethernet

A wired network in which each computer is connected to the communication bus.

Switch-based Ethernet

A wired network in which a switch connects different parts of the network and uses multiple ports to communicate with nodes.

Traceroute

A network diagnostic tool used to track the real-time pathway taken by data on a network from source to destination.

TCP (Transmission Control Protocol)

A connection-based protocol that ensures reliable data transfer by using acknowledgements and a 3-way handshake.

UDP (User Datagram Protocol)

A connectionless protocol that sends packets without acknowledgements, providing faster but less reliable data transfer.

Socket

A virtual 'mailbox' created by the socket API for each application to access network services.

Port

A number that distinguishes different sockets in an application.

Well Known Ports

Port numbers (0 to 1023) used by the OS, default applications, services, and network admin.

Registered Ports

Port numbers (1024 to 49151) used by network users and applications with no administrative privileges.

Iterative Server

A server that handles one client at a time, putting incoming connections into a queue when busy.

Concurrent Server

A server that handles multiple clients at the same time by creating child server processes or threads.

Unconnected UDP

A type of UDP socket in which the client does not connect the socket to a specific server.

Connected UDP

A type of UDP socket in which the client uses the connect call to specify the server's IP address and port number.

Layering

The concept of dividing the complex system of the internet into modular layers to handle it more effectively.