Computer Networks in FE Electrical

Computer Networks in FE Electrical is considered the most heated and crucial exam topic per the NCEES® guidelines for the FE Electrical exam. By preparing for the computer networks for the FE Electrical exam, you can prepare yourself not only for exam preparation but also for several professional roles that will help you grow in your career.

This study guide for Computer Networks in FE Electrical will help you unwrap all the critical topics related to computer networks and crack this crucial exam topic. Let’s dive deep into the details.

Basics of Computer Networks

The central theme behind the basics of computer networks for the Electrical FE Exam revolves around the systematic study and comprehension of the complex interconnectivity of closely connected and synchronized devices and communication protocols that enable the seamless exchange of digital information.

It involves a comprehensive understanding of networking principles, including but not limited to data transmission, network topologies, addressing schemes, and various networking protocols such as TCP/IP.

Understanding the fundamentals of computer networks in FE Electrical is essential for students to design, implement, and manage robust computer networks that cater to diverse communication requirements.

Types of Computer Networks (LAN, WAN, MAN, PAN, GAN)

Computer networks can be in various forms, each tailored to specific spatial and operational requirements. Let’s explore some common types of Computer Networks for the Electrical FE Exam in detail.

Local Area Network (LAN)

A Local Area Network (LAN) is a network confined to a limited geographic area, typically within a single building or campus. LANs facilitate high-speed communication among connected devices, utilizing Ethernet as a standard wired technology.

In wireless LANs, Wi-Fi is commonly employed. LANs operate at data transfer rates of 10 Mbps to 1 Gbps, with recent advancements supporting even higher speeds. They adhere to protocols like Ethernet (IEEE 802.3) for wired connections and Wi-Fi standards such as 802.11ac or 802.11ax for wireless connectivity.

Wide Area Network (WAN)

Wide Area Networks (WANs) cover more significant geographical regions, connecting multiple LANs across cities, countries, or continents. WANs employ various technologies to facilitate long-distance communication, including leased lines, dedicated connections, and public networks.

Common WAN technologies include Frame Relay, ATM (Asynchronous Transfer Mode), and MPLS (Multiprotocol Label Switching). Depending on the technology and infrastructure, data transfer rates in WANs can range from 1.5 Mbps (T1) to multiple Gbps.

Metropolitan Area Network (MAN)

A Metropolitan Area Network (MAN) operates within the scope of a metropolitan area, bridging the gap between LANs and WANs. MANs are characterized by high-speed connections using technologies like fiber optics.

These networks are suitable for interconnecting multiple LANs within a city or large campus. MANs often leverage protocols such as SONET (Synchronous Optical Network) or DWDM (Dense Wavelength Division Multiplexing) for high-speed data transmission.

Personal Area Network (PAN)

Personal Area Networks (PANs) are designed for connecting devices in close proximity to an individual, typically within a range of a few meters. Bluetooth is a standard technology used in PANs, facilitating wireless communication between devices like smartphones, laptops, and wearable devices. PANs operate at relatively low data transfer rates, usually up to 3 Mbps for Bluetooth 4.0 and higher.

Global Area Network (GAN)

Global Area Networks (GANs) provide worldwide connectivity and leverage various technologies for global communication. Satellite communication is a critical component of GANs, facilitating connectivity in remote or geographically challenging areas.

GANs often rely on satellite links, undersea cables, and terrestrial networks. These networks enable the seamless exchange of data on a global scale, catering to international businesses, research institutions, and global enterprises.

Networking Devices and Components

Networking devices are crucial in facilitating efficient and secure data exchange within a computer network. Each device serves a specific purpose in managing and directing data traffic, ensuring reliable communication. Below is an overview of various networking devices and components you must have heard.

Router

Routers operate at the OSI model’s network layer (Layer 3), directing data packets between different networks. They make intelligent decisions based on IP addresses, optimizing the most efficient path for data transmission.

*OSI will be discussed in complete detail in the following section of this blog.

Routers use routing tables and protocols such as OSPF (Open Shortest Path First) or BGP (Border Gateway Protocol) to determine the best path. They may employ Network Address Translation (NAT) to manage private IP addresses within a local network.

Switch

Switches operate at the data link layer (Layer 2) and are responsible for forwarding data frames within a local network. They use MAC addresses to make forwarding decisions, creating a more efficient and secure network than hubs.

Switches use MAC address tables to learn and store the associations between MAC addresses and physical ports. They employ protocols like STP (Spanning Tree Protocol) to prevent loops in the network.

Hub

Hubs operate at the physical layer (Layer 1) and broadcast data to all connected devices. They lack the intelligence of switches and can lead to network congestion and collisions. Hubs do not examine the data they transmit; they merely replicate incoming signals to all connected devices. This can result in inefficient use of bandwidth.

Modem

Modems (Modulator-Demodulator) convert digital data from a computer into analog signals for transmission over analog communication channels, such as telephone lines. On the receiving end, they convert incoming analog signals back into digital data.

Modems use modulation techniques to encode digital data onto analog signals for transmission and demodulation to convert received analog signals back into digital data.

Network Gateway

Gateways serve as entry and exit points between different networks, facilitating communication between networks that use different communication protocols or have different data formats. They are basically protocol converters and operate at multiple OSI layers. They analyze and translate data at the application layer, making them more complex than routers.

Firewall

Firewalls are designed to monitor, filter, and control incoming and outgoing network traffic based on predetermined security rules. They are a barrier between a secure internal network and untrusted external networks.

Firewalls can be hardware-based or software-based. They inspect packets, apply access control policies, and may perform stateful packet inspection to track the state of active connections.

How these Network Devices Work in Synchronization – Workflow Explained

• Modem: Converts digital data from a computer into analog signals for transmission over analog communication channels.
• Router: Receives the analog signals, demodulates them, and determines the best path for data packets based on IP addresses.
• Firewall: Examines incoming and outgoing packets, applying security rules to filter and control network traffic.
• Switch: Forwards data frames within the local network based on MAC addresses, creating efficient point-to-point connections.
• Gateway: Translates data between different networks, enabling communication between networks with different protocols or data formats.

Network Topologies (Bus, Star, Ring, Mesh, Hybrid)

Network topology refers to the arrangement of nodes (devices such as computers, printers, and servers) and the interconnections between them in a computer network. Different topologies offer distinct advantages and disadvantages, impacting factors like reliability, scalability, and ease of maintenance.

Here, we’ll unwrap the fundamental network topologies:

Bus Topology

In a bus topology, all devices share a standard communication line. Data is transmitted in both directions, and each device has a unique address. Devices can access the shared communication medium, but collisions may occur.

Star Topology

All devices connect to a central hub or switch in a star topology. The central hub facilitates communication between devices; if one connection fails, it doesn’t affect others. However, the central hub becomes a single point of failure.

Ring Topology

Description: In a ring topology, devices are connected in a closed loop, and data circulates in one direction. Each device has exactly two neighbours for communication. While it eliminates collisions, a single point of failure can disrupt the entire network.

Hybrid Topology

A hybrid topology combines two or more different topologies to benefit from their respective strengths. For example, a network might incorporate star and bus topology elements. This allows for greater scalability and flexibility.

Token Flow

Hybrid topologies incorporate elements of multiple topologies, such as a combination of star, bus, ring, or mesh; the token flow in a hybrid topology depends on the specific combination. For example:

Star-Bus Hybrid: In a network with a star-bus hybrid, the central hub (star) may employ token passing to manage communication with the peripheral devices (bus).

Ring-Mesh Hybrid: In a network combining ring and mesh, the ring section may use token passing for orderly data transmission within the ring. Whereas the mesh part allows direct device communication without a token.

Token passing is typically associated with specific topologies like rings, where it helps regulate access to the network. In hybrid topologies, the token flow is adapted to the characteristics of the individual components. The goal is to optimize network performance, reliability, and scalability based on the specific needs and requirements of the network architecture.

More About Token Passing

Token passing is a protocol used in network topologies, particularly ring topologies. In this method, a small data packet, known as a token, circulates the network. Only the device holding the token can transmit data. This mechanism helps control access to the network, minimizing collisions and ensuring orderly data transmission.

In a ring topology, for instance, a token circulates sequentially from one device to the next. When a device has the token, it can send data. After transmission, the token moves to the next device. Token passing prevents data collisions and ensures fair access to the network. In mesh and hybrid topologies, where token passing is less common, devices communicate more directly without a circulating token.

Networking Protocols and Data Transmission Concepts

Understanding network protocols is another critical area of mastering computer networks in FE Electrical. Networking protocols are a set of rules and conventions that govern the communication between devices in a computer network.

They define how data is formatted, transmitted, received, and acknowledged across the network. Protocols ensure that devices understand and interpret the information, facilitating seamless and standardized data transmission.

Data transmission involves moving data over a communication medium from one device to another. Several key concepts are fundamental to understanding data transmission:

• Data Rate (Bit Rate): The speed at which data is transmitted, typically measured in bits per second (bps), kilobits per second (kbps), megabits per second (Mbps), or gigabits per second (Gbps).
• Bandwidth: The maximum capacity of a communication channel to transmit data. It determines how much data can be sent in a given time.
• Latency: The time it takes for data to travel from the source to the destination. It includes transmission, propagation, and processing delays in computer networks.
• Throughput: The amount of data transmitted successfully over the network in a specific period. It may be lower than the data rate due to network congestion and retransmissions.
• Protocols and Standards: Specific rules and conventions governing how devices communicate. Standards ensure compatibility and uniformity, enabling devices from different manufacturers to interoperate.

To cover this topic in more detail, read our detailed study guide on Transmission and Networking in FE Electrical.

Network Architecture and Models

Network architectures define the structure and organization of computer networks. It significantly impacts the organization and workflow of computer networks.

The two common network architectures you must know in computer networks in the FE Electrical include:

Client-Server Architecture

In a client-server architecture, network resources are distributed between clients (user devices) and servers (dedicated machines providing services or data). Clients request servers for resources or services, and servers respond to these requests.

A clear distinction between client and server roles characterizes this model. It is commonly used in environments where centralized control and resource management are essential, such as web or cloud servers handling multiple client requests.

Peer-to-Peer Architecture

In a peer-to-peer architecture, all devices in the network, called peers, have equal status and can act as clients and servers. Peers can share resources and services directly with each other without the need for a centralized server. This decentralized model is often used in file-sharing applications and collaborative environments (like WhatsApp).

End-to-End or Peer-to-Peer Encryption

End-to-end encryption (E2EE) is a security measure that ensures data is encrypted on the sender’s device and can only be decrypted by the intended recipient, providing high privacy. In the context of peer-to-peer communication, E2EE is crucial for securing data during transmission.

How does end-to-end encryption work (Example: WhatsApp)?

End-to-end encryption ensures that communication remains confidential, even if the data traverses untrusted or compromised networks. It is critical to secure peer-to-peer communication, protecting users from eavesdropping and unauthorized access to their messages. This is how end-to-end encryption works in WhatsApp.

• Key Exchange: When two users initiate a chat on WhatsApp, their devices perform a key exchange to establish a secure communication channel. Each user has a public key and a private key.
• Encryption: Messages are encrypted using the recipient’s public key on the sender’s device. This encrypted message can only be decrypted by the recipient’s private key.
• Transmission: The encrypted message is sent over the network. Even if intercepted, the encrypted data is unreadable without the recipient’s private key.
• Decryption: The recipient’s device uses its private key to decrypt the received message, making it readable only to the intended recipient.
• Forward Secrecy: WhatsApp employs the Signal Protocol for E2EE, providing forward secrecy. This means even if an attacker gains access to a user’s private key in the future, they cannot decrypt past messages because each message has a unique encryption key.

OSI Model and Its Layers

The OSI (Open Systems Interconnection) model is a conceptual framework that standardizes the functions of a telecommunication or computing system into seven abstract layers. Each layer performs specific tasks and interacts with adjacent layers to ensure a standardized and efficient communication process.

Let’s see how each layer in the OSI model, from bottom to top, works in totality:

Physical Layer

Commencing at the Physical Layer, the initial step involves the encoding and transmitting raw binary data over the chosen physical medium. This layer is concerned with the modulation of signals, determining voltage levels, and utilizing specific physical connectors to establish the fundamental communication link between devices.

Data Link Layer

Proceeding to the Data Link Layer, the transmitted data is encapsulated into frames, facilitating reliable communication between directly connected nodes.

This layer meticulously manages error detection and correction mechanisms, ensuring the integrity of the transmitted data and counter delays in computer networks. Protocols such as Ethernet and Point-to-Point Protocol (PPP) operate here, contributing to the establishment of a dependable link.

Network Layer

As data progresses to the Network Layer, the focus shifts to routing and forwarding data packets between devices on different networks. The Internet Protocol (IP), a quintessential protocol at this layer, handles logical addressing, allowing for the identification of devices across various network segments.

Transport Layer

Transitioning to the Transport Layer, the emphasis is on end-to-end communication management. This layer ensures the integrity and reliability of the data exchange.

The Transmission Control Protocol (TCP) provides a connection-oriented approach with seamless flow control and error recovery mechanisms to curb any delays in computer networks. At the same time, the User Datagram Protocol (UDP) offers a connectionless, expedited alternative.

Session Layer

The Session Layer assumes control over establishing, maintaining, and terminating connections between applications on distinct devices. It orchestrates sessions, enabling synchronization, checkpointing, and recovery of data exchange, thereby ensuring the integrity of the communication session.

Presentation Layer

Elevating to the Presentation Layer, data undergoes translation, encryption, and compression procedures to guarantee its presentation in a universally readable format. This layer orchestrates data format conversions, character set translations, and encryption/decryption processes, facilitating seamless device compatibility.

Application Layer

Here comes the Application Layer; the apex layer directly engages with end-user applications. It delivers network services directly to user applications like email, file transfer, and web browsing.

Protocols like Hypertext Transfer Protocol (HTTP), File Transfer Protocol (FTP), and Simple Mail Transfer Protocol (SMTP) operate at this layer, serving as the conduit for user-level communication and interaction with the network.

Comparison of OSI Model and TCP/IP Model

While both models serve as conceptual frameworks for understanding network architecture, the TCP/IP model has gained broader adoption due to its simplicity and practicality, particularly in the context of the Internet.

Although comprehensive and detailed, the OSI model is often considered more theoretical and has seen less direct implementation in real-world networking scenarios.

The TCP/IP model’s four layers—Link/Network Access, Internet, Transport, and Application—align closely with the protocols and technologies commonly used in modern networking environments.

Conclusion

You now have a rich understanding of how computer networks work, including their critical components, types, and processes involved. For comprehensive FE Electrical exam preparation, check out our detailed study guides, courses, and other helpful resources at Study for FE – your go-to, trusted, and most authentic platform for FE exam preparation.

Wasim Asghar – P.E, P.ENG, M.ENG

Licensed Professional Engineer in Texas (PE), Florida (PE) and Ontario (P. Eng) with consulting experience in design, commissioning and plant engineering for clients in Energy, Mining and Infrastructure.

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