Commonly Used Network Devices

Introduction to Network Devices

A network is a collection of computers, servers, mainframes, network devices, and peripherals connected to one another to facilitate the sharing of data. Below are some of the commonly used network devices, which play a crucial role in establishing and maintaining these connections.

Commonly Used Network Devices

Bridge

A network bridge joins two different computer networks using the same protocol to enable them to work as a single network. Bridges are commonly used with local area networks (LANs) to extend their reach to cover larger physical areas. Besides building up larger areas, bridges are also employed to segment larger networks into smaller ones. The bridge achieves this by placing itself between the two portions of two physical networks and controlling the flow of data between them. It has the capacity to block the incoming flow of data as well. There are three types of bridges:

• Transparent Bridge: This device is invisible to other devices on the network. It only blocks or forwards data as per the protocol set.
• Translational Bridge: This device supports conversion. It converts the data format of one network to another and has the capability of connecting two different networks.
• Source Route Bridge: This device is set in the path which the packet takes through the network and is implanted within the packet. It is mainly used in Token Ring networks, which are seldom used these days. The diminishing popularity of Token Ring makes the chances that you’ll work with a source-route bridge very slim (Stallings, 2013).

Router

A router is a device that joins several computer networks together via wired or wireless connections. It routes data from a LAN to another network connection. A router allows only authorized machines to connect to other computer systems. Most routers have the capability to keep log files about the local network activity, which can be vital for monitoring and troubleshooting network issues (Tanenbaum & Wetherall, 2011).

Digital Subscriber Line (DSL) Modem

A digital subscriber line (DSL) modem enables a computer to connect to the Internet via an Internet Service Provider. DSL offers a substantial increase in Internet performance compared to a dial-up connection, providing users with a more seamless browsing experience (Comer, 2004).

Switch

A switch is a device used to network multiple computers together. Switches have many Ethernet ports that can connect to computers, cables, DSL modems, and other switches. High-end switches have more than 50 ports and are often rack-mounted. Switches can limit the traffic to and from each port so that each device connected to the switch has a sufficient amount of bandwidth. However, switches do not have the ability to provide firewall and logging capabilities (Forouzan, 2006).

Network Interface Cards (NICs)

Network Interface Cards (NICs) are hardware devices that connect a computer to the network. They are installed on the motherboard and have the capability to develop a physical connection between the network and the computer. Computer data is translated into electrical signals sent to the network via Network Interface Cards. The wired NIC uses cables and connectors as a medium to transfer data, whereas in the wireless card, the connection is made using an antenna that employs radio wave technology. All modern laptop computers incorporate wireless NICs in addition to the wired adapter. Network Interface Cards are available with different speeds, such as 10Mbps, 100Mbps, and 1000Mbps (Gigabit). The standard network cards are built with Gigabit (1000Mbps) connection speed. However, the speed of the card depends on the speed of the LAN (Kurose & Ross, 2012).

Hub

A hub is the most basic networking device. It connects multiple computers or network devices to form a single network segment, allowing computers to communicate directly with each other. It has several Ethernet ports used to connect two or more network devices together. Each computer or device connected to the hub can communicate with any other device connected to one of the hub’s Ethernet ports. There are three basic types of hubs:

• Passive Hub: It has no power supply, thus does not provide any processing or regeneration of data. It only shares physical media.
• Active Hub: It has a power supply, thus has the ability to regenerate data before being retransmitted and strengthens the signals in case of disturbance.
• Intelligent Hub: An intelligent hub functions as an active hub. It is stackable and can join one or more hubs together to extend the number of ports. They have a microprocessor chip and have the capability to perform diagnostics, which is useful in troubleshooting. It can be remotely managed (Peterson & Davie, 2007).

References:

• Comer, D. E. (2004). Computer Networks and Internets (4th ed.). Prentice Hall.
• Forouzan, B. A. (2006). Data Communications and Networking (4th ed.). McGraw-Hill Education.
• Kurose, J. F., & Ross, K. W. (2012). Computer Networking: A Top-Down Approach (6th ed.). Pearson.
• Peterson, L. L., & Davie, B. S. (2007). Computer Networks: A Systems Approach (4th ed.). Morgan Kaufmann.
• Stallings, W. (2013). Data and Computer Communications (10th ed.). Prentice Hall.
• Tanenbaum, A. S., & Wetherall, D. J. (2011). Computer Networks (5th ed.). Prentice Hall.