Ethernet Networking Basics Quiz

Data Communications and Networking

• This book, Data Communications and Networking, with TCP/IP protocol suite, sixth edition, by Behrouz A. Forouzan, is a textbook.
• It covers data communication and networking concepts.

Chapter 1: Introduction

• Data communication is the exchange of data between two devices via a transmission medium, with several characteristics: delivery, accuracy, timeliness, and jitter.
• A data communications system has five components: message, sender, receiver, transmission medium, and protocol.

Chapter 1: Message

• Information comes in various formats: text, numbers, images, audio, and video.
• Data representation is key: text via Unicode representation, numbers in binary, images via RGB/YCM bit patterns, audio as analog or digital signals, and video as a stream of images.
• Data communication modes include simplex, half-duplex, and full-duplex.

Chapter 1: Data Flow

• Simplex communication is one-way. Only one device can send or receive.
• Half-duplex communication is two-way but only one device can communicate at a time.
• Full-duplex communication is two-way and both devices can communicate simultaneously.

Chapter 1: Networks

• A network connects multiple devices for communication. Devices include hosts (computers, phones), and connecting devices like routers, switches, and modems.
• Network criteria include performance (transit time, response time), reliability (failure frequency, recovery time, robustness), and security.

Chapter 1: Network Criteria

• Performance is measured by transit time and response time. Transit time is how long a message takes to travel from one device to another. Response time is the time between an inquiry and a response.
• Reliability is measured by the frequency of failure, recovery time after failure, and robustness during disasters.
• Security is about protecting data from unauthorized access and damage. Protection includes implementing policies and procedures for breaches and data losses.

Chapter 1: Physical Structures

• Physical topology refers to the physical layout of a network.
• Common topologies include mesh, star, bus, and ring.

Chapter 1: Types of Connection

• Point-to-point connection connects two devices directly.
• Multipoint connection connects multiple devices through a shared medium.

Chapter 1: Network Types

• LAN (Local Area Network): Privately owned, connects devices in a limited area (office, building, campus).
• WAN (Wide Area Network): Connects devices over a large geographical area (city, country, or globally).
• WAN types: point-to-point and switched.

Chapter 1: Internet

• An internetwork (or simply internet), consists of interconnected networks. The modern Internet is a large internetwork.
• The Internet is a network of interconnected networks.

Chapter 1: Protocol Layering

• Protocols are rules defining how devices communicate.
• Layering in protocols is designed to make communication simpler; each layer manages a specific aspect of the task.
• A critical concept in protocol layering is that layers perform opposite tasks in each direction.

Chapter 2: Physical Layer

• The physical layer transmits individual bits across a physical medium.
• It's crucial for electrical and physical signaling.
• Signals: analog and digital forms; composite signals are made of multiple sine waves.
• Impairments: Attenuation, distortion, noise affect signal quality and distance.

Chapter 2: Signals

• Analog signals can be periodic (sine waves) or aperiodic, with characteristics like peak amplitude, period, frequency, and phase.
• Digital signals have discrete values and are non-periodic.

Chapter 2: Signal Impairment

• Attenuation means loss of signal power over distance.
• Distortion means changes in the signal's form or shape.
• Noise means random disturbance of the signal.

Chapter 2: Digital Transmission

• Digital signals are typically non-periodic, characterized by bit rate (bits per second).
• Bit Rate is the number of bits transmitted per second.

Chapter 2: Transmission Media

• Guided media use physical conductors (e.g., twisted-pair cable, coaxial cable, fiber-optic cable)
• Unguided media use electromagnetic waves (e.g., radio waves, microwaves, infrared signals)

Chapter 3: Data-Link Layer

• The Data Link Layer manages the transmission of data packets.
• It's responsible for error control (detecting and correcting errors), flow control (regulating data transmission rates to prevent overflows), framing (packaging data into frames), and media access control (managing access to the shared transmission medium).

Chapter 3: Media Access Control (MAC)

• Protocols like ALOHA, CSMA, CSMA/CD, and token passing manage access to shared media, aiming to minimize collisions.
• ALOHA is a simple random access method, butprone to collisions.
• CSMA is a more improved way of accessing a shared channel. CSMA/CD (Carrier Sense Multiple Access/Collision Detection) detects and resolves collisions; a crucial concept is to send a jamming signal to alert the other nodes of the collision.
• Token passing involves passing a special token to allow access to the shared medium, preventing collisions.

Chapter 3: Link-Layer Addressing

• Link-layer addresses (e.g., MAC addresses) identify specific devices on a network link.
• Three address types (unicast, multicast, broadcast) are used in link-layer protocols.
• ARP (Address Resolution Protocol) translates IP addresses to link-layer addresses.

Chapter 4: Local Area Networks (LANs)

• Ethernet, Wi-Fi (IEEE 802.11), and Bluetooth are common LAN technologies.
• Ethernet implementations have evolved over time, differing in data rates and physical media.

Chapter 4: Ethernet

• A fundamental concept is the 64-byte minimum and 1518-byte maximum frame length.
• The original Ethernet followed CSMA/CD, which handles collisions: a network must be configured carefully to minimize the time it takes to detect a collision so it can be resolved in a suitable way. Ethernet originally had only one physical implementation, but over time several different implementations were defined.
• A crucial consideration is the concept of auto-negotiation, which lets network adapters auto-detect the best speeds and modes.

Chapter 4: Wi-Fi (IEEE 802.11)

• This is a comprehensive standard for providing wireless local area networks (WLAN). Common features include: the basic service set (BSS), and the extended service set (ESS) as well as the MAC and the associated protocols

Chapter 4: Bluetooth

• Bluetooth is another wireless LAN technology, primarily designed to operate on a piconet network (a configuration of 8 devices). It is a flexible technology, often used for peer-to-peer device connectivity in relatively short ranges

Chapter 5: The Internet Layer

• Important technologies and standards to understand the network layer, to define addresses, to communicate between hosts, and to perform routing algorithms
• Hierarchical routing is used in the Internet: Each router can be configured to know information about only several routers in the environment. This greatly reduces the size of the routing tables; the required knowledge to send packets to destinations

Chapter 7: Network Layer: Data Transfer

• Packetizing, routing, forwarding are all core services for network layer
• The concept of Error control, Flow control, and Congestion control are all discussed.

Chapter 7: Internet Protocol V4 (IPv4)

• IPv4 is a widely used protocol for addressing devices on the Internet. A critical concept is that addresses can be combined into blocks which dramatically simplifies the routing and handling of data on the network.
• The three common notations used to show an IPv4 address are binary, dotted-decimal, and hexadecimal notations. The three common sections discussed for IPv4 addresses are: network, host, and prefix.
• IPv4 has a 32-bit address space
• Classful addressing was a previous way of dividing the large address space. The classless approach is easier to manage due to the growth of the Internet.

Chapter 7: Internet Protocol V6 (IPv6)

• IPv6 is intended to solve the address exhaustion problem with IPv4 due to the exponentially growing number of networked devices. IPv6 has a larger address space (128-bit) than IPv4 (32-bit). It uses a different hierarchical addressing scheme
• The three common notations used to show an IPv6 address are binary, colon-hexadecimal.

Chapter 8: Network Layer: Routing of Packets

• Unicast routing, routing algorithms (distance vector, link state), and protocols are explained.
• The general concept of unicast routing in an internetwork is described through an example of a graph.
• Various routing protocols and algorithms are discussed, with examples such as distance vector (DV) routing, and a corresponding algorithm showing how to calculate the least cost/optimal route to the destination
• Key concepts like link-state (LS) routing and least-cost tree in routing are explained; the concept of routing tables, how the algorithms find the best routes are explained with visual aids.

Chapter 9: Transport Layer

• The transport layer manages communication between processes on different hosts.
• Key services provided (including flow and error control) and their importance for applications.
• Protocols: User Datagram Protocol (UDP), Transmission Control Protocol (TCP), Stream Control Transmission Protocol (SCTP).
• UDP is connectionless, unreliable, very simple.
• TCP is connection-oriented, reliable, supports error control, flow control, and multiplexing.
• SCTP: is a relatively new protocol that combines features of UDP and TCP. 

Chapter 10: Application Layer

• The application layer provides communication services to the user, and it is the layer that the user interacts with
• Two models: 1) client-server and 2) peer-to-peer
• Common applications like the World Wide Web (WWW), File Transfer Protocol (FTP), Electronic Mail (e-mail) use the services provided by the application layer
• The applications can be introduced (and the concepts related to each) using a simple example that can clarify how the application works.  

Test your knowledge on Ethernet networking, including frame structure, addressing, and the functions of network layers. This quiz covers key concepts such as Ethernet frame lengths, MAC addresses, and the role of the network interface card (NIC).