Minimum components to configure a LAN;
2 PC’s
NOS (Network Operating System)
NIC (Network Interface Card)
Drivers
Cables & Connectors
Components in details:
Network Operating System (NOS)
Before discussing NOS lets try to understand what an Operating System (OS) is. An OS is a platform through which a hardware interacts with a user. It is a software that enables users and applications to interact with the computer. The main OS’s are; Microsoft, LINUX, Novel Netware, SUN Solaris, Macintosh (MAC). UNIX forms the core for OS’s such as LINUX, MAC, SUN Solaris and Novel Netware.
A network operating system (NOS) is a software program that controls other software and hardware that runs on a network. It also allows multiple computers, also known as network computers, to communicate with one main computer and each other, so as to share resources, run applications, and send messages, among other things. A computer network can consist of a wireless network, local area network (LAN), a wide area network (WAN), or even two or three computer networks. The heart of any of these networks, however, is the network operating system.
The most commonly used OS’s in networking are Microsoft and LINUX. LINUX is also called as Open Source, as anyone can edit the code of an OS in LINUX. But, Microsoft is known as a Closed Source, as its OS cannot be edited. Lets learn about Microsoft. Now Microsoft has two OS’s, one is the Desktop Operating System (DOS) and the second is Windows. DOS has many versions starting from v1.7, v2.7, .... . Similarly, Windows started with v1.0 to v5.0, after v5.0 came Win 95, then 98, 98SE, NT (which is the first Networking OS), ME, 2000, XP, 2003, Vista, 2008 and Windows 7. OS such as Win XP Home, Win Vista Home Basic, Win Vista Premium, Win 7 Home Basic and Win 7 Premium does not support Networking. OS such as Win 2000 Server, Win 2003 Server and Win 2008 Server supports Networking. The NOS has two sides, the Server side and the Client side. Each Server has its corresponding client systems.
Server Client
Win 2000 Server --> Win 2000 Professional
Win 2003 Server --> Win XP Professional
Win 2008 Server --> 7 Ultimate
Note: A person who provides service is called a Server. If you want to make a system a WebServer you will have to add a service called IIS (Internet Information Service). A WebServer is the place from where you can access the information you need via internet.
Win 2003 Server --> Win XP Professional
Win 2008 Server --> 7 Ultimate
Note: A person who provides service is called a Server. If you want to make a system a WebServer you will have to add a service called IIS (Internet Information Service). A WebServer is the place from where you can access the information you need via internet.
Network Interface Cards (NIC)
A network interface card, more commonly referred to as a NIC, is a device that allows computers to be joined together in a LAN, or local area network. It converts the signal that comes from the cables to a language that the computer system can understand. Networked computers communicate with each other using a given protocol or agreed-upon language for transmitting data packets between the different machines, known as nodes. The network interface card acts as the liaison for the machine to both send and receive data on the LAN.
The most common language or protocol for LANs is Ethernet, sometimes referred to as IEEE 802.3. A lesser-used protocol is Token Ring. When building a LAN, a network interface card must be installed in each computer on the network and all NICs in the network must be of the same architecture. For example, all must either be Ethernet cards, Token Ring cards, or an alternate technology.
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| Network Interface Card |
An Ethernet network interface card is installed in an available slot inside the computer. The NIC assigns a unique address called a MAC (Media Access Control) to the machine. The MACs on the network are used to direct traffic between the computers. The back plate of the network interface card features a port that looks similar to a phone jack, but is slightly larger. This port accommodates an Ethernet cable, which resembles a thicker version of a standard telephone line. Ethernet cable must run from each network interface card to a central hub or switch. The hub or switch acts like a relay, passing information between computers using the MAC addresses and allowing resources like printers and scanners to be shared along with data. When buying components for a LAN, make sure the NICs and hub or switch have the same capabilities. The entire network must be either wired or wireless, so a wireless network interface cannot talk to a wired switch or hub.
Note: For those who wish to connect LANs located in different areas of the city, state or country, ATM (Asynchronous Transfer Mode) can create wide area networks or WANs by connecting LANs together. LANs are still built with a network interface card in each networked computer, but ATM uses broadband Internet access to link the LANs to online ATM switches. This type of ATM WAN is referred to as an Internetwork.
MAC: Media Access Control aka Hardware address, Physical address or Burned address. This is a 48bit address. This 48bit address is split in two by IEEE (Institute of Electrical and Electronics Engineers), of which 24bits is called a Vendor ID or OUI (Organization Unique Identifier) and the other 24bits is called a Customer ID or OAI (Organization Assigned Identifier)
MAC: Media Access Control aka Hardware address, Physical address or Burned address. This is a 48bit address. This 48bit address is split in two by IEEE (Institute of Electrical and Electronics Engineers), of which 24bits is called a Vendor ID or OUI (Organization Unique Identifier) and the other 24bits is called a Customer ID or OAI (Organization Assigned Identifier)
Drivers
The software provided by the manufactures inorder for their hardware to work are called Drivers.
To see the drivers for each devices in your computer;
- Right click on My Computer icon on the desktop
- Click on the option Manage
- Click on Device Manager - Right click on My Computer icon on the desktop
- Click on the option Manage
To see the drivers click on the device and it will drop down to show the corresponding drivers
To update the drivers for a device you just need to Right Click on the driver. See below;
Cables & Connectors
There are four types of cables used in networking; Co-axial cables, UTP cables, STP cables and OFC cables.
Co-axial cables
There are two types of co-axial cables;
i) Thinnet cables -> Speed is 10BASE2
ii) Thicknet cables -> Speed is 10BASE5
Explained: 10BASE2
‘10’ denotes the speed, 10Mbps
‘2’ stands for segment length, ie 200mts
Though the segment length is 200mts in theroy, in practical you get only 185mts
In 10BASE5 the segment length is 500mts and in practical you get the full 500mts.
On a Thinnet cable you can connect a maximum of 30 PC’s, where as on a Thicknet cable you can connect a maximum of 100 PC’s.
Thicknet cables are costly to implement, difficult to configure and the speed is very low, however one advantage is its length.
The connect used in co-axial cables is called BNC (Bayonet Connector / British Naval Connector) This connector is normally connected at the very end of the cables.
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| BNC Connector |
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| Tee Connector |
This type of connector is used to connect multiple PC’s to a cable. They are also called ‘Vampire Tap’, as shown in the fig below;
UTP Cables (Unshielded Twisted Pair)
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| UTP Cable |
The reason why these wires are twisted is to reduce EMI (Electro Magnetic Reduction). The connectors used in UTP cables are called RJ45.
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| RJ45 Jack |
Note:
Categories in Cables;
Categories Speed
CAT 1 ---> 10Mbps
CAT2 ---> 10Mbps
CAT3 ---> 16Mbps
CAT4 ---> 100Mbps
CAT5 ---> 1000Mbps
CAT5e --> 1000Mbps
CAT6 --> 10000Mbps
*‘e’ stands for enhanced Color Code Standard in UTP cables:
Class A
1. Green/White
2. Green
3. Orange/White
4. Blue
5. Blue/White
6. Orange
7. Brown/White
8. Brown
Class B
1. Orange/White
2. Orange
3. Green/White
4. Blue
5. Blue/White
6. Green
7. Brown/White
8. Brown There are three types of UTP cables;
i) Straight through cables - To connect dissimilar devices
PC to Switch
PC to Hub
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| Both ends of the cable is Class B color coded. |
ii) Cross over cables - To connect similar devices
PC to PC
Switch to Switch
Hub to Hub
PC to Router
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| One end of the cable is Class A and the other end is Class B. |
iii) Roll over cables - Used in Router configuration
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| One of the cable is Class B and the other end is the reverse of Class B. |
The process of connecting a Jack to a UTP cable is called ‘Crimping’. A Crimper can be used to crimp RJ11, RJ45 and RJ12 jacks.
If you would like to see how to use this device check the video link below;
STP Cable (Shielded Twisted Pair)
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| Difference between UTP and STP cable |
These type of cables are used in industrial level, For eg; in heavy machineries. They are also very expensive cables.
OFC (Optical Fibre Cables)
An optical fiber cable is a cable containing one or more optical fibers. Used in under sea cabling and for covering long distances. Data travels at the speed of light.
Protocols
A protocol is a set of rules that governs the communications between computers on a network. In order for two computers to talk to each other, they must be speaking the same language. Many different types of network protocols and standards are required to ensure that your computer (no matter which operating system, network card, or application you are using) can communicate with another computer located on the next desk or half-way around the world.Basically, there are two types of Protocols;
Access Protocols
Communication Protocols
Protocols used to establish a communication between two machines in a network is called Access Protocols.
Examples; Token Ring, CSMA/CD, CSMA/CA
Token Ring protocol works within a device called MAU (Multiple Access Unit) in a Ring Topology. These type of protocols are used in networks like ARCNET.
To understand how a Token Ring works visit the link below;
http://www.datacottage.com/nch/troperation.htm
One of the biggest problems with an Ethernet network, is that if two computers decide to send messages at exactly the same moment, the signals will get "mixed-together", as they attempt to share the same physical medium. This is called a "collision", and both messages involved in a collision will ruined, and need to be re-sent. Thus, one of the most important communication protocols used on an Ethernet is the "Carrier Sense Multiple Access with Collision Detection", or CSMA/CD protocol. This protocol lays down a set of rules for how collisions are detected on the network, and what the offending computers should do about it to ensure that the messages get re-sent without causing another collision (the basic ideas is, wait for some random time period, then try again).
In CSMA/CA, as soon as a node receives a packet that is to be sent, it checks to be sure the channel is clear (no other node is transmitting at the time). If the channel is clear, then the packet is sent. If the channel is not clear, the node waits for a randomly chosen period of time, and then checks again to see if the channel is clear. This period of time is called the backoff factor, and is counted down by a backoff counter. If the channel is clear when the backoff counter reaches zero, the node transmits the packet. If the channel is not clear when the backoff counter reaches zero, the backoff factor is set again, and the process is repeated.
FDDI (Fibre Distributed Data Interface)-
This type of access protocols are mainly used in OFC (Optical Fibre Cables) for communication.
Communication Protocols -
There are two types of communication protocols;
- Routed Protocols
- Routing Protocols
Examples for Routing Protocols are;
RIP (Routing Information Protocol)
IGRP (Interior Gateway Routing Protocol)
EIGRP (Enhanced IGRP)
OSPF (Open Shortest Path First)
BGP (Border Gateway Protocol)
Note: Routing Protocols will be covered in details later
Examples of Routed Protocols are;
AppleTalk –
This type of protocol is used for communication purpose between systems in Apple computers.
IPX/SPX (Internet Packet Exchange / Sequential Packet Exchange) –
This type of protocol is used for communication in Novel Netware systems. Computers MAC address or Physical address is used in this process for communication.
NetBEUI (Netbios Enhanced User Interface) –
This protocol was developed by IBM but used in Microsoft machines. NetBEUI provides your small network with the ability to translate user-friendly computer names to an IP address. Routers do not route this protocol across the network. NetBEUI broadcasts a signal to all computers on the network taking up more bandwidth, so it is only useful on local networks with a few computers connected using a hub. This type of protocol can only support a maximum of 200 PC’s. Removing NetBEUI also frees up computer resources, which can improve performance. However, before removing NetBEUI from the computer, ensure TCP/IP is installed. TCP/IP (Transmission Control Protocol / Internet Protocol) –
TCP/IP is the communication protocol for the internet. TCP and IP were developed by the American Department of Defense (DOD). TCP/IP defines the rule computers must follow to communicate with each other over the internet. TCP/IP is a two-layer program. The higher layer, Transmission Control Protocol, manages the assembling of a message or file into smaller packets that are transmitted over the Internet and received by a TCP layer that reassembles the packets into the original message. The lower layer, Internet Protocol, handles the address part of each packet so that it gets to the right destination. Each gateway computer on the network checks this address to see where to forward the message.
