Networking

Data Communication

The exchange of data between two or more devices through a transmission medium such as cable or air. It involves transmitting digital or analog data between devices.

Delivery

The ability to ensure that data reaches the correct destination.

Accuracy

The ability to ensure that data is delivered without errors or changes.

Timeliness

The ability to ensure that data is delivered within the required or appropriate time.

Jitter

The variation in the time it takes for packets to arrive at their destination.

Message

The actual information or data being transmitted between devices.

Sender

The device that sends or initiates the transmission of data.

Receiver

The device that receives the transmitted data.

Transmission Medium

The physical or wireless path used to carry data from the sender to the receiver.

Protocol

A set of rules that controls how devices communicate and exchange data.

Connectivity

The ability of devices to connect and communicate with each other.

Efficiency

The ability of a network to transmit and share data while minimizing time, cost, and resource use.

Productivity

The ability of data communication to support communication, collaboration, and completion of tasks.

Scalability

The ability of a network to expand and support additional devices, users, or traffic when needed.

Foundation of IT

The basic communication infrastructure that supports modern information technology systems and services.

Transmission Media

The pathways used to carry data from one device to another.

Two Main Categories of Transmission Media

Guided media and unguided media.

Guided Media

A type of transmission medium where signals travel through a physical path such as a cable.

Guided Media

Uses a physical medium to direct and contain signals as they travel from the source to the destination, providing a controlled and more secure path while reducing interference and signal loss.

Twisted

Pair Cable

Unshielded Twisted

Pair (UTP)

Shielded Twisted

Pair (STP)

Twisted

Pair Cable

Coaxial Cable

A cable consisting of a central copper conductor, insulation, a metallic shield, and an outer protective jacket.

Coaxial Cable

Used for cable television, broadband connections, and some older network systems.

Fiber Optic Cable

A cable that transmits data using light signals through thin strands of glass or plastic. It provides high bandwidth, supports long

Single

Mode Fiber (SMF)

Multi

Mode Fiber (MMF)

Unguided Media

A type of transmission medium where signals travel through air or free space without using a physical conductor.

Unguided Media

Allows signals to travel wirelessly through electromagnetic waves from the sender to the receiver.

Radio Waves

Electromagnetic waves used to transmit data wirelessly over different distances.

Microwaves

High

Infrared

A type of electromagnetic radiation used for short

Network Devices

Hardware devices used to connect, manage, and control communication between devices in a network.

NICs (Network Interface Cards)

Hardware components that allow devices to connect and communicate with a network. They provide network connectivity, convert data into signals for transmission, use a unique MAC address to identify the device, and can be wired or wireless.

Routers

Network devices that connect different networks and forward data packets between them using IP addresses. They determine the appropriate path for data packets and allow communication between separate networks.

Switches

Network devices that connect multiple devices within a Local Area Network and forward data to the appropriate destination using MAC addresses. They allow devices within a LAN to communicate efficiently and reduce unnecessary traffic.

Network Topology

The arrangement or structure of devices and connections within a computer network.

Physical Topology

The actual physical arrangement of devices, cables, and other network components.

Logical Topology

The way data flows between devices within a network, regardless of the physical arrangement.

Bus Topology

A network topology where all devices are connected to a single main communication cable called a backbone. Data travels along the backbone and can move in both directions. It is simple and inexpensive but can be difficult to troubleshoot and maintain.

Star Topology

A network topology where all devices are connected to a central device such as a switch or hub. It is easy to install, manage, and troubleshoot, but failure of the central device can affect the connected devices.

Ring Topology

A network topology where devices are connected in a circular arrangement. Data travels from one device to another around the network, and a failure in one device or connection can affect communication throughout the network.

Mesh Topology

A network topology where devices are connected to multiple or all other devices. It provides high reliability and multiple paths for data transmission but is expensive and complex to install and maintain.

Tree Topology

A hierarchical network topology that combines characteristics of star and bus topologies. It uses a hierarchical arrangement with a central or root connection and multiple levels of connected devices. It is scalable but depends on the main or backbone connections.

Hybrid Topology

A network topology that combines two or more different types of network topologies. It is flexible and scalable but can be more expensive and complex to design and maintain.

Circuit Switching

A switching method that establishes a dedicated communication path between two devices before data transmission begins. The path remains reserved for the communication until the session ends.

Packet Switching

A switching method that divides data into smaller units called packets, which are transmitted through a network and reassembled at the destination.

Datagram Packet Switching

A packet switching method where each packet is treated independently and may travel through different routes to reach the destination.

Virtual Circuit Packet Switching

A packet switching method where a logical path is established before transmission and the packets follow that path.

Message Switching

A switching method where the complete message is stored at an intermediate device before being forwarded to the next device.

Store

and

Router

A Layer 3 network device that connects different networks and forwards data packets based on IP addresses.

Network Switch

A network device that connects multiple devices within the same LAN and forwards data frames based on MAC addresses.

Differences Between a Router and a Switch

A router connects different networks and uses IP addresses, while a switch connects devices within a LAN and primarily uses MAC addresses.

Static Routing

A routing method where routes are manually configured in a router's routing table and remain unchanged until manually modified.

Dynamic Routing

A routing method where routers automatically determine and update routes based on changes in the network.

Direct Routing

A routing method where the source and destination devices are on the same network, allowing data to be sent directly without passing through another router.

Default Routing

A routing method that uses a predefined route when no specific route to the destination is available.

Default Route

A route used by a router when no specific route exists for the destination network.

Gateway of Last Resort

The default path used by a router when it does not have a specific route for the destination.

Next Hop

The next router or network device to which a data packet is forwarded on its way to the destination.