WAN Concepts and Protocols Quiz

Computer Network Components

• Computer network components are the major parts needed to install software.
• Important components include NIC, switch, cable, hub, router, and modem.
• Component selection depends on the type of network (e.g., wireless networks might not require cables).

NIC (Network Interface Card)

• NIC is a hardware component used to connect a computer to a network.
• It connects a computer to another computer on a network.
• It supports transfer rates from 10, 100 to 1000 Mb/s.
• Each NIC has a unique MAC address assigned by IEEE.
• The MAC address is stored in Programmable Read-Only Memory (PROM).
• There are two types of NICs: wired and wireless.

Wired NIC

• Wired NICs are installed inside the motherboard.
• Cables and connectors are used for data transfer.

Wireless NIC

• Wireless NICs are used in devices like laptops.
• Wireless NICs use antennas for wireless network connections.

Hub

• A hub is a hardware device that divides the network connection among multiple devices.
• When a computer requests information, the hub broadcasts the request to all devices on the network.
• All devices check if the request is for them; otherwise, the request is dropped.
• The process of using the hub consumes more bandwidth.
• Hub use is obsolete.

Switch

• A switch is a hardware device that connects multiple devices on a computer network.
• Switches have more advanced features than hubs.
• It contains an updated table to determine where to transmit the data.
• A switch delivers messages directly to the correct destination, rather than broadcasting to all devices like a hub.
• It increases network speed.

Router

• A router is a hardware device connecting a Local Area Network (LAN) to an internet connection.
• It receives, analyzes, and forwards incoming packets to another network.
• It works at Layer 3 (Network Layer) of the OSI model.
• It forwards packets based on the routing table.
• It determines the best path for packet transmission.
• Advantages include: security, reliability, and performance enhancement.

Modem

• A modem allows a computer to connect to the internet over existing telephone lines.
• It is not integrated on the motherboard.
• It modulates and demodulates signals.
• Modems vary in speed and transmission rates, classifying them into categories like standard PC modems, cellular modems, and cable modems.

Cables and Connectors

• Cables are transmission media for signals.
• Twisted pair cable is a common type of transmission cable.

Computer Network Types

• A computer network connects computers to share data, resources, and applications.
• Networks are categorized by size:
  • LAN (Local Area Network): Connects devices in a small area like a building or office.
  • MAN (Metropolitan Area Network): Connects devices over a larger geographical area (city).
  • WAN (Wide Area Network): Connects devices over very large geographical areas (e.g., countries).
  • PAN (Personal Area Network): Connects devices around a person (e.g., Bluetooth devices).

Personal Area Networks (PANs)

• Personal Area Network connects devices around a person, usually within a 10-meter range.
• There are two types of PANs: Wireless and Wired.
• Wireless PANs use wireless technologies like Wi-Fi and Bluetooth.
• Wired PANs use USB connections for connecting devices.

Metropolitan Area Networks (MANs)

• A MAN network spans a larger geographical area than a LAN, typically encompassing a city or a metropolitan area.
• It uses communication infrastructure like telephone exchange lines and other options.
• It interconnects various LANs geographically and operates at higher speed than LANs.

Wide Area Networks (WANs)

• A WAN covers a large geographical area, like a state, country or globally and often uses multiple interconnected networks.
• It can be used for business, government, and education purposes.
• It interconnects different LANs using communication technologies.
• WAN's have widely varying speed and other operational standards.

Extranet

• An extranet is a communication network using internet protocols for sharing information.
• Access is restricted to specific users.
• An extranet can be a MAN or WAN.

Intranet

• An intranet is a private network for organizational communication. It's used to share information and resources internally, for employees specifically.
• It is based on internet protocols.

Network Topology

• Topology shows how network components are interconnected.
• Types of topology include:
  • Bus topology
  • Ring topology
  • Star topology
  • Tree topology
  • Mesh topology
  • Hybrid topology

Bus Topology

• All devices are connected to a single cable (backbone).
• Data sent by one device is received by all other devices.
• Signal interference if devices send simultaneously.
• Easy to install, but difficult to troubleshoot.
• Less efficient for heavy traffic.

Ring Topology

• Devices are connected in a circular loop.
• Data flows in one direction.
• All devices in the network can receive the packet.
• Uses token passing, to avoid collision.
• Failure in one node affects the entire network.

Star Topology

• All devices connect to a central hub or switch.
• Data flows through the central device to the intended recipient.
• Easy to install and troubleshoot.
• Failure of one device does not affect the entire network.
• Central point of failure, the hub or switch goes down.
• More cables required, and the cost can increase.

Tree Topology

• Combining star and bus topology characteristics, forming a hierarchical structure.
• Easy to manage and expand.
• Error detection and correction are comparatively easy.
• Failure of one device does not always affect the entire network.

Mesh Topology

• Each device is interconnected with all other devices, creating redundant paths.
• Multiple paths provide high reliability.
• Complex to set up and manage, especially with many devices.

Hybrid Topology

• Combining various topologies.

OSI Model

• This model describes internet communications, a 7-layer architecture.
• The layers are: Application, Presentation, Session, Transport, Network, Data Link, Physical.
• Application, presentation, and session layers manage data representation, connections, and formatting.
• The transport layer provides reliable transmission across networks.
• The network layer manages logical addressing and routing.
• Data link manages physical addressing and frames.
• The physical layer manages physical transmission media.

TCP/IP Model

• This model describes internet communications, a 4-layer architecture.
• The layers are: Application, Transport, Internet, Network Access.
• Simpler, combines some OSI layers.
• Application, transport, and network layers manage data representation, connections, and formatting.
• The internet layer manages logical addressing and routing.
• Network access manages physical addressing and frames to connect to the physical hardware.

Switching Techniques (Circuit, Packet, and Message)

• Circuit switching establishes a dedicated path between sender and receiver, suitable for voice.
• With packet switching, messages are broken into packets independently, suitable for data and better for handling high traffic.
• Message switching: uses node storage and forwarding, with no dedicated path, suitable for bursty data and large messages.

Data Link Protocols

• Protocols for noiseless/noisy channels are different (e.g., Simplex, Stop-and-Wait, Go-Back-N, Selective Repeat ARQs).
• Stop-and-Wait, a simplistic protocol, where each packet transmits only after sending an acknowledgement from the receiver.
• Go-Back-N and Selective-Repeat ARQ deal with errors and acknowledgements to compensate for losses or changes.

Channel Allocation

• In multi-user environments, techniques are used to share a channel.
• Static allocation assigns fixed channels to users, good for predictable, consistent/ low user activity scenarios.
• Dynamic allocation (e.g., CSMA, CSMA/CD, CSMA/CA, TDMA, FDMA, CDMA) is used when users need flexibility.

Network Layer

• The network layer in the OSI model (layer 3) is to deliver messages between end-to-end hosts.
• It is concerned with addressing, routing, and overall end-to-end delivery.
• Protocols like IP, TCP, and UDP form the bulk of the network layer.

Network Services

• Networks provide several services, including directory services for managing user accounts and authentication, file services for sharing files, and communication services like email and social media.
• Network layer services like routing and addressing facilitate inter-network communication.

Software-Defined Networking (SDN)

• SDN uses software to manage networking devices instead of solely relying on those devices.
• SDN creates flexibility in managing the network structure and resources.