Network Topologies Quiz

Data Communications

• Telecommunication means communication at a distance, including telephony, telegraphy, and television. "Tele" is Greek for "far."
• Data refers to information in any form agreed upon by those creating and using it.
• Data communications involves exchanging data between two devices via a transmission medium, such as a wire cable.

Communication System

• Data communications requires hardware (physical equipment) and software (programs).
• Effective data communications depend on four characteristics: delivery, accuracy, timeliness, and jitter.

Communication System Characteristics

• Delivery: Data must reach the correct destination.
• Accuracy: Data must be delivered accurately.
• Timeliness: Data delivery should be timely, especially in real-time applications like video and audio.
• Jitter: Variation in packet arrival time, leading to uneven delays in audio or video transmission.

Components of a Data Communication System

• Message: The information to be conveyed (e.g., text, numbers, images, audio, video).
• Sender: The device initiating the transmission.
• Receiver: The device receiving the message.
• Medium: The physical path for transmitting the message (e.g., twisted-pair wire, coaxial cable, fiber-optic cable, radio waves).
• Protocol: A set of rules governing data communication between devices. Protocols ensure devices can understand each other.

Data Representation

• Data can be represented in various forms including text, numbers, images, audio, and video.

Data Flow

• Simplex: Unidirectional communication (one-way street). Examples include keyboards and traditional monitors.
• Half-duplex: Devices can transmit and receive, but not simultaneously. Examples include walkie-talkies.
• Full-duplex: Devices can transmit and receive simultaneously. Examples include telephone networks.

Networks

• A network is a collection of devices (nodes) connected by communication links.
• Nodes can be computers, printers, or other devices able to send and receive data.
• Distributed Processing: Dividing a task among multiple computers in a network instead of a single large computer.

Network Criteria

• Performance: Measured using factors like transit time, response time, throughput, and delay.
• Reliability: Measured using accuracy of delivery, frequency of failure, time-to-recover, and robustness.
• Security: Addressing unauthorized access and data protection, including policies and procedures for recovery.

Types of Connections

• Point-to-Point: A dedicated link between two devices (e.g., remote control to television).
• Multipoint (Multidrop): Multiple devices share a single link (either spatially by using the same cable simultaneously, or temporally by taking turns).

Physical Topology

• Topology: Geometric representation of the network's structure and relationships among devices.
  • Mesh: Every device is linked to every other device with dedicated point-to-point links.
  • Star: Devices are connected to a central controller (hub). Data flows through the hub to reach the destination.
  • Bus: Devices share a single cable. Data travels along the cable.
  • Ring: Devices are connected in a ring. Data travels around the ring.
  • Hybrid: Combination of different topologies.

Network Models

• OSI Standard: A 7-layer model for network architecture.
• TCP/IP Model: A common model used in the internet. Note that the OSI model is a conceptual model, whereas TCP/IP is a practical implementation.

Exercises

• Exercises are included in the presentation to test student understanding of concepts discussed. Specific exercise details include different network configurations and their characteristics.