WHAT ARE THE DIFFERENT NETWORKING DEVICES?

Network Devices

     These are the devices that connect the end devices together to allow then to communicate. They can be in the form of switches, hubs, or concentrators, etc.

The Hub

     A hub is a simple device that directs data packets to all devices connected to it. Basically, a hub does nothing except provide a pathway for the electrical signals and regenerate signal before it forwards it to all connected devices.

     In a hub, a message is passed along or "broadcast" to every one of its ports. It does not matter that the message is only destined for one port. The hub has no way of distinguishing which port a message should be sent to. Passing it along to every port ensures that it will reach its intended destination. This places a lot of traffic on the network and can lead to poor network response times.

The Switch

     Similar to hubs, switches are the connectivity point of a wired network. Devices are connected via twisted-pair cabling, one for each device. The difference between two is in how the devices deal with the data that they receive.

     If a hub forwards the data it receives to all ports on the device, a snitch forwards the data it receives only to the port that connects to the destination device.

     A switch keeps a record of the MAC addresses or the unique identity of the client devices connected to it. With this information stored in a switch, it can identify which system is sitting on which port. Thus, when a message is received, it knows exactly which port to send it to. This significantly increases the network response times.

The Router

     Routers are completely different devices. If a hub or switch is concerned with transmitting frames, the job of a router, as its name implies is to route packets to other networks until that packet ultimately reaches its destination. It can transmit through wired and wireless networks.

     A router is typically connected to at least two networks, commonly two Local Area Networks (LANs) or Wide Area Networks (WANs) or a LAN and its Internet Service Provider's network.

    Routers have a WAN port that connects to an Internet connection provided by your Internet Service Provider; the integrated switch allows users to easily create a LAN. This allows all the PCs on the LAN to have access to the Internet, Windows file, and printer sharing services. Routers might have a single WAN port and a single LAN port and are designed to connect an existing LAN hub or switch to a WAN. Switches and hubs can be connected to a router with multiple PC ports to expand a LAN.

Other Network Devices:

The Bridge

     A Bridge is used to divide larger networks into smaller sections. It is located between two physical network segments and manages the flow of data between the two. By looking at the physical address of the devices connected to each segment, bridges can forward the data if the destination address is on another interface, or block it from crossing if verified that it is on the interface from which it came.

Types of Bridges

1. Transparent Bridge - derives its name from the fact that the devices on the network are unaware of its existence. This bridge does nothing except block or forward data based on the  MAC address.

2. Source route bridge - is used in Token Ring networks. The source route bridge derives its name from the fact that the entire path to be taken by the packet through the network is embedded within the packet.

3. Translational bridge - is used to convert one networking data format to another; for example, from Token Ring to Ethernet, and vice versa.

The Network Card

     A Network Card, also called the Network Interface Card, is a device that enable computers to connect to the network.

To install or configure a network interface, you will need drivers of the device. You might also need to configure it, although many devices are now plug and play. Most network cards are now software configured. Many of these software configuration utilities also include testing capabilities. The drivers and software configuration utilities supplied with the cards are often not the latest available, so it is best practice to log on to the internet and download the latest drivers and associated software.

The Modem

     A Modem, short for modulator/

demodulator, is a device that converts the digital signals generated by a computer into analog signals that can travel over conventional phone lines.

The modem converts the signal back at the receiving end. It converts it into a format the computer can understand. A modem can be used as a means to connect to an ISP, or as a mechanism for dialing up to a LAN. A modem can also be internal add-in expansion cards or external devices that connect to the serial or USB port of a system. It can also be PCMCIA cards designed for use in laptops, or proprietary devices designed for use on other devices such as portables and handhelds.

The Transceivers

     The Transceiver is responsible for placing signals onto the network media and detecting incoming signals travelling through the same wire.

In terms of networking, transceivers can be shipped as a module or chip type.

> Chip transceivers are small and are inserted into a system board or wired directly on a circuit board.

> Module transceivers are external to the network and are installed and function similar to other computer peripherals or they can also function as stand-alone devices.

Several Types of the transceivers are RF transceivers, fiber optic transceivers, Ethernet transceivers, wireless (WAP) transceivers, and more. Each of these media types are different though the function of the transceivers remains the same. Each type of the transceivers used has different characteristics, such as the number of ports available to connect to the network and whether it functions as a full-duplex communication if supported.

The Firewall

     A firewall is a networking device that can be either hardware or software-based. It controls access to your organization's network. This controlled access is designed to protect data and resources from outside threat. 

A typical firewall is placed at entry/exit points of a network. For example, placing a firewall between an internal network and the internet. When in place, it can control  access in and out of that point. The firewall is configured on the server to allow or permit certain types of network traffic. In small offices and in regular home use, a firewall is commonly installed on the local system and configured to control traffic.

SOURCE:

D Whiz Book Computer 10 - All of the Information
HL9B2 hub
Network-Hub.jpg network hub
8161whRObCL._SL1500_.jpg switch
2011-11-29_132204.jpg network switch
Linksys_EA8300_MaxStream@2x.jpg router
the-relationship-between-computers-and-router.jpg router network
SimpleBridgedNetworkDiagram.png bridge
F6733093-01.jpg network card
7297_Modems_750x375._V273560377_.png modem
SGETF1039-110.jpg transceiver
1111-6.png firewall