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Fundamentals of Ethernet (IEEE 802.3 and DIX)

Ethernet is the popular LAN technology to create a home network. IEEE 802.3 defines the technical aspects of an Ethernet.

Ethernet is a LAN media type that uses CSMA/CD to send information and functions at the Data Link Layer of the OSI Reference Model.


Which Topology Ethernet Uses?

Ethernet media types having different physical topologies but support a single logical topology: bus topology. I will explain the different kinds of topologies supported by Ethernet later.


Ethernet supports Bus logical topology only.


We can design an Ethernet LAN with different shapes (using different physical topologies), but the communication happens in Bus topology only.



Physical Topologies Supported By Ethernet

You must understand one point. Ethernet supports multiple physical topologies. However, the communication happens in bus topology only.

  1. Bus topology

  2. Star Topology

  3. Point to Point

Different Versions of Ethernet

It has two versions right now. One is the DIX version, and the second is the IEEE version. This tutorial explains various topologies and versions of Ethernet.


We have two versions of Ethernet now.


Let us check the two different Ethernet standards.

  1. DIX Version

    DIX Ethernet or Ethernet 2 is popular. This version does not split the Data Link layer into two. Ethernet 2 has a frame value of more than 1500. This standard is designed by the combined work of three companies.

    Those companies are DEC, Intel, and Xerox. This standard gets the name DIX by taking the first letter from the names of these three companies.

  2. IEEE Version

    This version of Ethernet comes under IEEE 802.2 and 802.3. Here, the data link layer has two divisions. They are LLC and MAC. To read more about it, visit the links below.



    We can easily distinguish between an IEEE ethernet and a DIX Ethernet. The Frame value of IEEE802.3 is less than 1500. It is the difference between IEEE and DIX versions.


To read more about the devices and protocols work in standard, visit the link below.

IEEE 802.11 WiFi Standards Backward Compatibility Checker

WiFi is the term used to denote Wireless Local Area Networks using IEEE802.11 wireless standards. Now, the term WiFi represents all Wireless Local Area Networks.


Wireless technologies use the IEEE 802.11 a, b, g, n, and ac standards.


The first part of this tutorial checks the term WiFi and the major 802.11 standards. You can also see a list of WiFi devices that support them.

You will get a backward compatibility checker chart in the last part of this tutorial.


Using this chart, you can make decisions on extending your WLAN networks.


With the help of the chart, you can avoid buying a device with compatibility issues with existing devices (standards that are not backward compatible).


IEEE 802.11 Wireless Standards Available In Industry

  1. IEEE 802.11 A

  2. IEEE 802.11 B

  3. IEEE 802.11 G

  4. IEEE 802.11 N

  5. IEEE 802.11 AC

Compatibility Between Different 802.11 Wireless Standards

Not all 802.11 technologies are backward compatible because of the different frequencies supported. So, if you plan to extend your current WLAN with new devices, ensure the new devices are compatible with existing devices.


It is critical to know the technologies supported by the existing equipment.


Once you have noted down the technologies (that are in your network), you may check which 802.11 standards are compatible with them. You can see a list of different WiFi standards that support each other.



If you see 'Yes' in that chart, the technologies in the row and column are backward compatible. On the other hand, if you see 'No' in the chart, it tells you the standards listed in rows and columns are not backward compatible.



WiFi StandardIEEE802.11a IEEE802.11b IEEE802.11g IEEE802.11n IEEE802.11ac
11aYes No No Yes Yes
11bNo Yes Yes Yes No
11gNo Yes Yes Yes No
11nYes Yes Yes Yes Yes
11acYes No No Yes Yes

Frequencies Supported By Different WiFi Standards

You must be wondering why different wireless standards cannot connect. The frequency mode supported is the primary reason for the incompatibility between different IEEE 802.11 technologies.



Let us check the frequencies supported by IEEE 802.11 WiFi connections.

1. IEEE 802.11 a ---5 GHz

2. IEEE 802.11 b ---2.4 GHz

3. IEEE 802.11 g ---2.4 GHz

4. IEEE 802.11 n -- Supports both 2.4GHz and 5GHz

5. IEEE 802.11 ac -- Supports 5GHz

The Four Different Kinds Of Wireless Networks

A wireless network uses a wireless signal to communicate between devices connected in the network. In a wireless network, we use signals like radio waves, microwaves, or infrared to send and receive data between two devices.


There are four types of wireless networks.


The Wireless network is of four types. They are Wireless LAN, MAN, WAN, and PAN. We mention them as WLAN, WMAN, WPAN, and W-WAN.



This article gives you a brief introduction to each type of WiFi network. We order them below according to the size of the area they cover.



Different Types of Wireless Networks

  1. Wireless Personal Area Network (WPAN)

    Wireless Personal Area Network (WPAN) transfer data between two devices in a short distance. Examples are Bluetooth and infrared.


    WPAN covers a short distance around a mother device or a single person.


    If you are looking for an example of a Wireless PAN, consider a WiFi keyboard and a WiFi mouse are them.

  2. Wireless Local Area Network (WLAN)

    WLAN uses IEEE 802.11 standards to communicate between devices. It is also called WI-Fi and operates in two frequencies ( 2.4GHz and 5GHz).


    WLAN Covers an office or Building.


    A Wireless LAN includes a WiFi router and wireless devices connected to it. To learn more about WLAN, click on the link below.



  3. Wireless Metropolitan Area Network (W-MAN)

    As the name suggests, a wireless network that covers an area equivalent to a metropolitan city is called WMAN.


    WMAN is larger than WLAN and smaller than W-WAN.


    The difference between MAN and W-MAN is the use of wireless technology to connect devices.


  4. Wireless Wide Area Network (W-WAN)

    A wireless network that covers a large area is a W-WAN. A Wireless WAN covers a lot more area than a WMAN covers. It is the largest wireless network.


You have learned the different kinds of wireless networks. Now, we will check a few examples.



Examples of Different Types of Wireless Networks

Now, we look into a few wireless networks and check which kind of network they are.

  1. At first, we check for an example of a Wireless Personal Area Network (WPAN). Consider a desktop computer and its wireless keyboard and mouse. Both wireless devices stay near the desktop computer and form a WPAN.

  2. Mobile networks cover a land area to enable mobile communication. Different cells use different radio frequencies to avoid possible interference with neighboring cells.



    You can categorize mobile networks under W-WAN. So, when somebody asks you for an example of W-WAN, name the mobile network.


  3. WiFi uses IEEE 802.11 standards and comes under WLAN. Examples are 802.11a, 802.11b etc. Each standard has its frequency and speed. For example, 802.11n is faster than 802.11a/b and g standards.


    WiFi is a Wireless LAN.


    Both band g standards work with 2.4 GHz frequency. However, 802.11a works at the 5GHz frequency. 802.11n standard works in both 2.4GHz and 5 GHz frequencies.

The Functions of A Wide Area Network (WAN)

A Wide Area Network (WAN) is a network that covers a large area. Its coverage extends from country to continent.


We can say a WAN is a connection of multiple LANs.


The primary function of a WAN is to connect two Local Area Networks located in different locations. When we need to connect two LANs at different locations separated by a long distance, we need WAN to connect them.

Different WAN services are available to connect two remote LANs. Once we connect two LANs with a WAN connection, we can communicate between them.


The best example of a WAN is the Internet.


Cable and DSL are the two most popular WAN connections. Other than these two, there is a list of WAN services available.



Application of WAN Services in Today's World

Without the concept of a Wide Area Network (WAN), there is no Internet. Without the Internet, none of the Information Technology developments were possible.



So, we can say WAN technology is the backbone of today's Information exchange. An example is this website. You are reading www.CoreNetworkZ.com on your mobile phone.

How is it possible? A WAN technology transfers this web page from the server to your mobile phone. Without a WAN, you cannot access this web page.



Another example is a corporate company that has offices in various countries. Communication between their offices works due to a WAN.



List of Popular WAN Services

  1. Digital Subscriber Line (DSL)

  2. Cable

  3. Dedicated circuits

  4. ATM

  5. Analog Dialup

  6. Frame Relay

  7. ISDN

  8. X.25

  9. SMDS (Switched Multi-megabit Data Services)

Popular Connection Types in WAN Services


There are four different connection types used in Wide Area Networks service. They are:
  1. Circuit-switched:

    Circuit-switched services provide a temporary connection using a phone circuit. Analog dialup and ISDN are examples of circuit-switched WAN connection types.


  2. Cell Switched:

    Cell Switched service uses dedicated connections, but it can connect multiple devices by a single device using the same interface. It is advanced compared to dedicated switched services.


  3. Packet Switched:

    Packet Switched services use variable-length packets to connect multiple devices from a single device over a dedicated connection.


  4. Dedicated connections:

    As the name suggests, it uses a dedicated connection to connect two devices.



Important WAN Network Devices:

Networking devices in Wide Area Networks are:


  1. DSL and Cable Modems

  2. Firewall

  3. Carrier Switches

  4. NT1s

  5. Routers

Metropolitan Area Network (MAN) And Examples

Metropolitan Area Network( MAN ) is a network that covers an area equivalent to a metropolitan city.

It is easier to understand this network by comparing other two popular networks. MAN covers a larger area than a LAN but smaller than a WAN. This type of network covers a few kilometers.

Let us check the examples of a Metropolitan Area Network. The cable TV network is an example of the Metropolitan Area Network. But there is a difference.


The classic example of a MAN is Metro Cable Network.


MAN is a computer network, but cable TV connection provides TV broadcasts. In a Metropolitan Area Network, two buildings in a city are connected and start data transfer. That means this connects two devices located far away but limited to a metropolitan location.



One of the differences between WAN and MAN is the connection speed. WAN offers low to medium connection speed, but Metropolitan Area Network offers high-speed connection.


Technologies Used in MAN


  1. ATM (Asynchronous Transfer Mode)

  2. FDDI

  3. SMDS

  4. Ethernet-based MAN

MAN Standards for Data Communication

Distributed Queue Dual Bus (DQDB) is the Metropolitan Area Network standard for data communication. It is in the IEEE 802.6 standard. Using DQDB, networks can be as long as 30 miles and operate at speeds of 34 to 155 Mbit/s.


Devices Provide MAN Connections

Devices used to provide connections here are:

  1. ATM

  2. High-end routers

  3. Switches

  4. Optical switches

Can a Corporate Company Campus Be Classified as MAN?

One comment I received was about the status of a corporate office campus.

I consider a corporate office campus as a Metropolitan Area Network. I understand that this network does not cover the area of a metropolitan city. However, per the definition, a MAN is a network of multiple Local Area Networks.


A corporate office campus is a MAN.


A corporate office campus must have multiple LANs. They are interconnected and come under the category of a MAN.

Basics of Computer Networking

A network consists of all devices connecting each other in order to communicate between them across a small or large distance. Major components in it are computers, connecting cables, router, switch etc. It is important to create a network to improve the efficiency of users by allowing them to send and receive information easily. They are classified into LAN, MAN, and WAN according to the area it covers. Let us check each type of networks here.


Network Types
  1. LAN

    To read more about LAN, click the link below.
    Local Area Network

  2. MAN

    For the details about the Metropolitan Area Network, click the link below.
    Metropolitan Area Networks

  3. WAN

    To learn more about it, click the link below.
    Wide Area Network

  4. Wireless Networks

    To learn more about it, visit the link below.
    Wireless Networks

Major Components in a Computer Network

All the hardware and software parts included in a network are network components. It includes computers, storage devices, hubs and switches, router, Ethernet cable etc. Let us check each one.
  1. Router

    To learn more about the component router, visit the link below.
    What is a Router and Its Major Functions

  2. DHCP

    To learn more about DHCP and its functions, click the link below.
    Dynamic Host Configuration Protocol

  3. Hub

    To read more about the functions of Hub in a computer network, follow the link below.
    Functions of Ethernet Hub

  4. ICMP

    To read how ICMP works in a network, visit the link below.
    Internet Control Message Protocol

  5. Range Expander

    Range Expander is an essential networking component in a wireless network. To read more about wireless range expander and its functions, click the link below.
    What is Wireless Range Expander

  6. ARP

    To learn more about Address Resolution Protocol and its working, click the link below.
    What is Address Resolution Protocol

  7. Adding Multiple  Routers

    In a big network, we may need to use multiple routers to connect all the network components. To perform this task, visit the link below.
    How to Perform Router Cascading

  8. VRRP

    One of the important software(protocol) components in a network are VRRP. To learn how VRRP works in a network, click the link below.
    Virtual Router Redundancy Protocol (VRRP)an overview

  9. FDDI

    FDDI is one if the important network topology. To read more about FDDI, visit the link below.
    Fiber Distributed Data Interface (FDDI)

  10. RPC- Session Layer Protocol

    To read more about RPC protocol and its working, visit the link below.
    What is Remote Procedure Call (RPC)

    If you face issues with RPC server, follow the instructions provided in the link below.
    RPC Server is Unavailable While trying to Renew IP Address

  11. WZC

    Wireless Zero Configuration has an important role in a wireless networking. To learn more about it, visit the link below.
    What is Wireless Zero Configuration

    In later versions of Windows, you cannot find WZC. Instead of WZC we have WLAN AutoConfig in Windows Vista onwards.
    How to Start WLAN AutoConfig in Windows 8 Computer

  12. Adapter

    Wireless adapter receives wireless signals from Access Point. To learn more about wireless adapter, click the link below.
    1. How to Enable Wireless Adapter
    2. Uses of Netstat Command


Transport Layer PING: Transmit failed Destination Net Unreachable
Destination host unreachable Enable Disabled Adapter Windows Automatic IP Address
SMART Command Failed TTL Expired in Transit Could not Find Host

Local Area Network (LAN) - CCNA Study Material

Local Area Network (LAN) is a collection of connected devices in a small area. A home network (one router connected to computers and smartphones) is an example of a LAN.


Ethernet is the popular LAN technology today.


LAN helps to communicate between devices in a smaller area and improve the efficiency of working in an office.


Which Network Is a LAN?

So, how do we decide if a network is a LAN? In a LAN, all devices are connected and can share data. A LAN covers a small area (such as an office building, home, etc.).


The media type used to connect devices in a Local Area Network(LAN) is Ethernet, FDDI, Token Ring, etc.


Let us consider common topologies used in Local Area Networks because it is in the CCNA Exam Syllabus.


Topology is of two types: physical and logical topology.


In Physical Topology, you can see how devices in a LAN are connected, but in Logical Topology, we can see how these devices communicate.



LAN Physical Topologies

  1. Point to Point

    If we connect two devices without interference from other devices, that is a Point-To-Point physical topology. In this LAN topology, these two devices can communicate without extra support.


    Wireless Bridge is an example of Wireless Point-to-Point Topology.


  2. Bus Topology

    You can say it is an extension of Point-to-Point topology. In Bus topology, we connect all devices in LAN in a single connection.


    Ethernet uses Bus topology.


  3. Ring

    If a Local Area Network has Ring Topology, all devices are in a ring form. It means PC 1 connects to PC 2. PC 2 connects to PC 3, and the last device connects to PC 1. So, it forms a ring structure.


    FDDI uses a ring topology.


  4. Star Topology

    In start topology, all devices in a LAN have a connection to the central device. An example is all the computers connected to a Switch.


LAN Logical Topologies


  1. Bus Topology

    Ethernet is an example of a LAN technology using a logical bus structure to communicate. To learn more about Ethernet, visit the link below.



  2. Ring Topology

    Token Ring is a good example that uses ring logical topology to communicate computers connected to the network.




The medium of Transmission in LAN

  1. Twisted-pair wire

  2. Coaxial cables

  3. Fiber optic cables