Computer network components include the major parts that are needed to install a network both at the office and home level. Before delving into the installation process, you should be familiar with each part so that you could choose and buy the right component that fits with your network system.
These hardware components include cable, Hub, Switch, NIC (network interface card), modem and router. Depending on the type of network you are going to install, some of the parts can be eliminated. For example, in a wireless network you don’t need cables, hubs so on.
In this article we will discuss about the main computer network components required to install simple computer network, often called LAN (local area network).Computer network is a group of two or more computers that connect with each other to share a resource. Sharing of devices and resources is the purpose of computer network. You can share printers, fax machines, scanners, network connection, local drives, copiers and other resources.
In computer network technology, there are several types of networks that range from simple to complex level. However, in any case in order to connect computers with each other or to the existing network or planning to install from scratch, the required devices and rules (protocols) are mostly the same.
Major computer network components
Computer network requires the following devices (some of them are optional):-
• Network Interface Card (NIC)
• Hub
• Switches
• Cables and connectors
• Router
• Modem
1. Network Interface Card
Network adapter is a device that enables a computer to talk with other computer/network. Using unique hardware addresses (MAC address)encoded on the card chip, the data-link protocol employs these addresses to discover other systems on the network so that it can transfer data to the right destination.
There are two types of network cards: wired and wireless. The wired NIC uses cables and connectors as a medium to transfer data, whereas in the wireless card, the connection is made using antenna that employs radio wave technology. All modern laptop computers incorporated wireless NIC in addition to the wired adapter.
Network Card Speed
Network Interface card, one of the main computer network components, comes with different speeds, 10Mbps, 100Mbps, and 1000Mbps, so on. Recent standard network cards built with Gigabit (1000Mbps) connection speed. It also supports to connect slower speeds such as 10Mbps and 100Mbps. However, the speed of the card depends on your LAN speed.
For example, if you have a switch that supports up to 100Mbps, your NIC will also transfer a data with this same speed even though your computer NIC has still the capability to transfer data at 1000Mbps (1Gbps). In modern computers, network adapter is integrated with a computer motherboard. However if you want advanced and fast Ethernet card, you may buy and install on your computer using the PCI slot found on the motherboard (desktop) and ExpressCard slots on laptop .
2. Hub
Hub is a device that splits a network connection into multiple computers. It is like a distribution center. When a computer request information from a network or a specific computer, it sends the request to the hub through a cable. The hub will receive the request and transmit it to the entire network. Each computer in the network should then figure out whether the broadcast data is for them or not.
Currently Hubs are becoming obsolete and replaced by more advanced communication devices such as Switchs and Routers.
3. Switch
Switch is a telecommunication device grouped as one of computer network components. Switch is like a Hub but built in with advanced features. It usesphysical device addresses in each incoming messages so that it can deliver the message to the right destination or port.
Like Hub, switch don’t broadcast the received message to entire network, rather before sending it checks to which system or port should the message be sent. In other words switch connects the source and destination directly which increases the speed of the network. Both switch and hub have common features: Multiple RJ-45 ports, power supply and connection lights.
4. Cables and connectors
Cable is one way of transmission media which can transmit communication signals. The wired network typology uses special type of cable to connect computers on a network.
There are a number of solid transmission Media types, which are listed below. - Twisted pair wire
It is classified as Category 1, 2, 3, 4, 5, 5E, 6 and 7. Category 5E, 6 and 7 are high-speed cables that can transmit 1Gbps or more. -
Coaxial cable
Coaxial cable more resembles like TV installation cable. It is more expensive than twisted-pair cable but provide high data transmission speed.
Fiber-optic cable
It is a high-speed cable which transmits data using light beams through a glass bound fibers. Fiber-optic cable is high data transmission cable comparing to the other cable types. But the cost of fiber optics is very expensive which can only be purchased and installed on governmental level.
5. Router
When we talk about computer network components, the other device that used to connect a LAN with an internet connection is called Router. When you have two distinct networks (LANs) or want to share a single internet connection to multiple computers, we use a Router.
In most cases, recent routers also include a switch which in other words can be used as a switch. You don’t need to buy both switch and router, particularly if you are installing small business and home networks.
There are two types of Router: wired and wireless. The choice depends on your physical office/home setting, speed and cost.
6. Modems
A modem enables you to connect your computer to the available internet connection over the existing telephone line. Like NIC, Modem is not integrated with a computer motherboard. It comes as separate part which can be installed on the PCI slots found on motherboard.
A modem is not necessary for LAN, but required for internet connection such as dial-up and DSL.
There are some types of modems, which differs in speed and transmission rate. Standard PC modem or Dial-up modems (56Kb data transmission speed), Cellular modem (used in a laptop that enables to connect while on the go), cable modem (500 times faster than standard modem) and DSL Modems are the most popular.
Repeater
A network device used to regenerate or replicate a signal. Repeaters are used in transmission systems to regenerateanalog or digital signals distorted by transmission loss. Analog repeaters frequently can only amplify the signal while digital repeaters can reconstruct a signal to near its original quality.
In a data network, a repeater can relay messages between subnetworks that use different protocols or cable types. Hubs can operate as repeaters by relaying messages to all connected computers. A repeater cannot do the intelligent routing performed by bridges and routers.
Bridge
In telecommunication networks, a bridge is a product that connects a local area network LAN to another local area network that uses the same protocol (for example, Ethernet or Token Ring). You can envision a bridge as being a device that decides whether a message from you to someone else is going to the local area network in your building or to someone on the local area network in the building across the street. A bridge examines each message on a LAN, "passing" those known to be within the same LAN, and forwarding those known to be on the other interconnected LAN (or LANs).
In bridging networks, computer or node addresses have no specific relationship to location. For this reason, messages are sent out to every address on the network and accepted only by the intended destination node. Bridges learn which addresses are on which network and develop a learning table so that subsequent messages can be forwarded to the right network.
Bridging networks are generally always interconnected local area networks since broadcasting every message to all possible destinations would flood a larger network with unnecessary traffic. For this reason, router networks such as the Internet use a scheme that assigns addresses to nodes so that a message or packet can be forwarded only in one general direction rather than forwarded in all directions.
A bridge works at the data-link (physical network) level of a network, copying a data frame from one network to the next network along the communications path.
DHCP Server
As long as you're learning about your IP address, you should learn a little about something called DHCP—which stands for Dynamic Host Configuration Protocol. Why bother? Because it has a direct impact on millions of IP addresses, most likely including yours.
DHCP is at the heart of assigning you (and everyone) their IP address. The key word in DHCP is protocol—the guiding rules and process for Internet connections for everyone, everywhere. DHCP is consistent, accurate and works the same for every computer. Remember that without an IP address, you would not be able to receive the information you requested. As you've learned (by reading IP: 101), your IP address tells the Internet to send the information that you requested (Web page, email, data, etc.) right to the computer that requested it.1
Those incredible protocols
There are more than one billion computers in the world, and each individual computer needs its own IP address whenever it's online. The TCP/IP protocols (our computers' built-in, internal networking software) include a DHCP protocol. It automatically assigns and keeps tabs of IP addresses and any "subnetworks" that require them. Nearly all IP addresses are dynamic, as opposed to "static" IP addresses that never change.
DHCP is a part of the "application layer," which is just one of the several TCP/IP protocols. All of the processing and figuring out of what to send to whom happens virtually instantly.
Clients and servers
The networking world classifies computers into two distinctive categories: 1) individual computers, called "hosts," and 2) computers that help process and send data (called "servers"). A DHCP server is one computer on the network that has a number of IP address at its disposal to assign to the computers/hosts on that network. If you use a cable company for Internet access, making them your Internet Service Provider, they likely are your DHCP server.
Permission slips
Think of getting an IP address as similar to obtaining a special permission slip from the DHCP server to use the Internet. In this scenario, you are the DHCP client—whenever you want to go on the Internet, your computer automatically requests an IP address from the network's DHCP server. If there's one available, the DHCP server sends a response containing an IP address to your computer.
Here is how the DHCP process works when you go online:
- Your go on your computer to connect to the Internet.
- The network requests an IP address (this is actually referred to as a DHCP discover message).
- On behalf of your computer's request, the DHCP server allocates (leases) to your computer an IP address. This is referred to as the DHCP offer message.
- Your computer (remember—you're the DHCP client) takes the first IP address offer that comes along. It then responds with a DHCP request message that verifies the IP address that's been offered and accepted.
- DHCP then updates the appropriate network servers with the IP address and other configuration information for your computer.
- Your computer (or whatever network device you're using) accepts the IP address for the lease term.
Wireless Access Point (WAP)
A wireless access point (WAP) is a hardware device or configured node on a local area network (LAN) that allows wireless capable devices and wired networks to connect through a wireless standard, including Wi-Fi or Bluetooth. WAPs feature radio transmitters and antennae, which facilitate connectivity between devices and the Internet or a network
.
A WAP is also known as a hotspot.
Wireless access points (WAP) may be used to provide network connectivity in office environments, allowing employees to work anywhere in the office and remain connected to a network. In addition, WAPs provide wireless Internet in public places, like coffee shops, airports and train stations.
Wireless access points are most commonly thought of in the context of the 802 series of wireless standards, commonly known as Wi-Fi. While there are other wireless standards, the vast majority of the time the terms Wi-Fi hotspot and WAP are synonymous.
FIREWALL
A firewall is a network security system, either hardware- or software-based, that controls incoming and outgoing network traffic based on a set of rules.Acting as a barrier between a trusted network and other untrusted networks -- such as theInternet -- or less-trusted networks -- such as a retail merchant's network outside of a cardholder data environment -- a firewall controls access to the resources of a network through a positive control model. This means that the only traffic allowed onto the network defined in the firewall policy is; all other traffic is denied.
DNS Servers
Domain name system servers match domain names like google.com to their associated IP addresses — 173.194.39.78 in the case of google.com. When you type google.com into your web browser’s address bar, your computer contacts your current DNS server and asks what IP address is associated with google.com. Your computer then connects to the IP address and displays “google.com” in your web browser – the connection to 173.194.39.78 happens behind the scenes.
The DNS servers you use are likely provided by your Internet service provider (“ISP”). If you’re behind a router, your computer is likely using your router as your DNS server, but the router is likely forwarding requests to your Internet service provider’s DNS servers.
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