Fundamentals of Ethernet

Ethernet is LAN media type that uses CSMA/CD to send information and functions at Data Link Layer of OSI Reference Model. Ethernet media type having different physical topologies but having single logical topology: bus topology. With various physical topologies we can design an this network with different shapes but the communication happens in Bus topology only. It has two versions right now. One of them is DIX version and the second is IEEE version. This tutorial explains various topologies and versions of Ethernet.

Physical Topologies Supported
  1. Bus topology

  2. Star Topology

  3. Point to Point

Two Versions Of Ethernet
  1. DIX Version

    DIX  Ethernet or Ethernet 2 is widely using now. This version does not split Data Link layer in to two. Ethernet 2 has frame value more than 1500. This standard is designed by the combined work of three companies. Those companies are DEC, Intel and Xerox. This standard is named as DIX by taking the first letter from the names of these three companies.

  2. IEEE Version

    This version of Ethernet is defined under IEEE 802.2/3. Here data link layer is sub divided in to LLC and MAC. To read more about it, visit the links below.

    Frame value of IEEE802.3 is less than 1500. This is the major difference between IEEE and DIX versions.

To read more about the devices and protocols work in standard, visit the link below.
Data Link Layer in OSI Reference Model

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What is WiFi & Different IEEE 802.11 Wireless Standards

Wi-Fi is the term used to denote Wireless Local Area Networks which are using IEEE802.11 wireless standards. Now the term WiFi is representing all Wireless Local Area Networks. Wireless technologies used in WiFi are IEEE 802.11a, b, g, n and ac. In this tutorial let us check what is WiFi and the major 802.11 standards. You can also see a list of WiFi devices which supports them. At the end of the tutorial, you can see a backward compatibility checker chart. Using this chart you can take decisions related to extending your WLAN networks. With the help of the chart you can avoid situations of buying a device which is not compatible with existing devices (standards which are not backward compatible).

IEEE 802.11 Wireless Standards Available In Industry
  1. IEEE802.11a

  2. IEEE802.11b

  3. IEEE802.11g

  4. IEEE802.11n

  5. IEEE802.11ac

Compatibility Between Different 802.11 Wireless Standards

Not all 802.11 technologies are backward compatible because of the different frequencies supported by different standards. So if you are planning to extend your current WLAN with new devices, you must make sure the new wireless devices you are going to buy are backward compatible with existing devices. So it is important to know the technologies supported by the existing equipments. Once you have noted down the technologies that are currently implemented, you may check which all 802.11 standards are compatible with them. You can see below a list of different WiFi standards which support each other. If you see 'Yes' in that chart, it shows the technologies those in the row and column are backward compatible. On the other hand if you see 'No', it tells the standards listed ion row and column 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

Frequency mode supported is the reason for the incompatibility between these IEEE technologies.

1. 11a ---5 GHz

2. 11b ---2.4 GHz

3. 11g ---2.4 GHz

4. 11n -- Supports both 2.4GHz and 5GHz

5. 11ac -- Supports 5GHz

List Of 802.11 Wireless Devices
  1. Belkin F5D8233-4  N Router Supports IEEE802.11n

  2. D-Link  Router Which Supports Various WiFi Standards

  3. D-Link  Access Point DWL-G700AP

  4. Configure Adapter in AdHoc mode

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IP Addressing Guide (IPv4 & IPv6 Addressing)

IP address is the third layer address in TCP/IP Protocol Stack, given to each devices connected to a network. In Internet layer of TCP/IP Protocol Stack, each device in a network is assigned with unique address known as IP address. There are two versions of TCP/IP: IPv4 and IPv6. Right now we are using IPv4 version to assign logical address to devices in a network. In this tutorial you will learn the differences between IPv4 addressing and IPv6 addressing with different classes of IPv4 addresses.

Differences Between IPv4 and IPv6

  1. Length

    IPv4 is 32 bit address broken in to four octets which are separated by a period. IPversion6 is 128 bit long address having the capability to give more addresses than IPversion4 offers. Examples of IPversion4 and IPversion6 addresses are given below.

    IPversion4 addressing : or in binary form 00001010 00000000 00000000 00000001
    IPv6 addressing : E3D7:0000:0000:0000:51F4:9BC8:C0A8:6420

  2. Representation

    IPv6 is 128 bit binary number represented in hexadecimals format. IPv4 is 32 bit binary number represented in decimal format.

  3. Capacity of possible addresses

    IPv6 can give more addresses than IPv4 addressing.

  4. Checksum field

    In IPv4 addressing header we can see checksum field but that is absent in IPv6 address header.

  5. Protocols Supported

    Another major difference between IPv4 addressing and IPv6 addressing is the supported protocols. IPversion4 supports ARP and IGMP. IPv6 support NDP and MLD.

Different Classes of IP Addresses

IPv4 addresses are divided in to five classes. They are:
  1. Class A addresses(Range from 1 to 126)

  2. class B addresses (Range from 128 to 191)

  3. Class C addresses (Range from 192 to 223)

  4. class D addresses (Range from 224 to 239)

  5. Class E addresses (Range from 240 to 254)

Suggested Tutorials
  1. Address Resolution Protocol (ARP)

  2. Internet Group Management Protocol (IGMP)

  3. Remote Procedure Call (RPC)

  4. Dynamic Host Configuration Protocol (DHCP)

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Bluetooth Technology

Bluetooth is a short distance wireless technology defined as IEEE 802.15.1 to create Personal Area Networks. Right now Bluetooth is widely used in mobile phones to send and receive data. According to Bluetooth technology there is a master and slave devices. A master device can connect to maximum seven slaves at a time. Frequency of Bluetooth is similar to IEEE 802.11 g/b. It is in the range 2.4 to 2.485 GHz. Major advantages of Bluetooth over Wi-Fi is its low cost and low power. However, Wi-Fi has wider range and faster data transfer rate.

Major Uses of Bluetooth Technology

There are variety of applications run with the help of Bluetooth technology. Some of the uses are:
  1. Make easy connection between mobile phones to send and receive files

  2. Bluetooth technology enables wireless mouse and keyboard

  3. Create a Local connection between PCs

  4. Helps to create short range wireless network

Different Versions of Bluetooth
  1. Bluetooth V1.1 and V1.2

  2. Bluetooth Version 2.0 +EDR

  3. Bluetooth V2.1 + EDR

  4. Bluetooth v3.0 + HS

  5. Bluetooth v4.0 and 4.1

Network Portal

Basic Wireless Networks Tutorial

Wireless network uses wireless signal to communicate between devices connected in the network. Here we use signals like radio waves, microwaves or infrared to send and receive data between two devices. Just like normal network types, they too classified in to Wireless LAN, MAN, WAN etc. They are mentioned as WLAN, WMAN and W-WAN respectively. This article gives you a brief introduction of each type of WiFi networks. We order them below according to the  size of area they cover.

Types of Wireless Networks
  1. WPAN

    Wireless Personal Area Network (WPAN) uses to transfer data between two devices which are in short distance. Examples are Bluetooth and infrared. Some of the applications like WiFi keyboard, WiFi mouse etc. To learn more about it visit the link below.
    An Explanation of Bluetooth Technology

  2. Wireless LAN

    WLAN uses IEEE802.11 standards to communicate between devices. It is also called WI-Fi and operates in different frequencies like 2.4GHz and 5GHz. To learn more about WLAN, click on the link below.
    Wi-Fi and Different IEEE802.11 Standards

  3. Wireless MAN & WAN

    These two types networks covers a large geographical area.

Popular  Tutorials
  1. WiFi Channels and Its Importance in Signal Quality

  2. Unable to See Any Signals From My Router

  3. How to Start WZC On Windows XP Computer

Some Examples of Wireless Networks
  1. Mobile Network

    Mobile networks cover a land area to enable mobile communication and is cell shaped. Different cells use different radio frequency to avoid any possible interference with neighboring cells. You can categorize mobile network under W-WAN.

  2. Wi-Fi

    As we explained above, Wifi use IEEE802.11 standards and comes under WLAN. Examples are 802.11a, 802.11b etc. Each standards has its own frequency and speed. For example 802.11n is faster than 802.11a/b and g standards. Both band g standards work with 2.4 GHz frequency. However, 802.11a works at 5GHz frequency. 802.11n standard works in both 2.4GHz and 5 GHz frequencies.
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What is Router & Major Functions

Router is a layer three (Network Layer in OSI Reference Model) device used to connect different networks. For example if you want to connect two networks one is FDDI and other is Ethernet, we need router. It also connects networks with different network address. To move information between devices having different network numbers, we need layer 3 device. Routers can switch packets on the same interface using VLANs.

Router and Routing Tables

Router makes routing decisions based on the routing table it has. Routing table consists of path information to send packets to neighboring routers. Routing table with routing protocols helps router to find shortest path to send packets to destination.

Examples of Routing Protocols

  1. Interior Gateway Routing Protocol (IGRP)

  2. Routing Information Protocol (RIP)

  3. Address Resolution Protocol (ARP)

  4. Internet Control Message Protocol (ICMP)

  5. Dynamic Host Configuration Protocol (DHCP)

Functions of Router

We cannot finish an article about routers without mentioning their functions. The major functions are:
  1. Router Connects Different Network Types

  2. It joins networks with different network addresses

  3. It finds shortest path to send packets to destination

  4. It defines logical address schemes

  5. Router supports VLANs

  6. Router has features like Quality of Service and Filtering

  7. It builds routing tables to make layer 3 decisions fast

Links to Router Configuration Guides

Here we provide links to some of our popular configuration and troubleshooting guides.

  1. How to Configure Belkin Wireless Device By Manual Steps

  2. AutoConfigure Belkin F5D8233-4 Router

  3. Configure D-Link DIR-865L Amplifi Cloud  5700 With Cable & DSL

  4. How to Setup D-Link Wireless

  5. Setup D-Link WiFi WBR-2310

  6. How to Setup Linksys WRT54G  in PPPoE Mode

  7. How to Configure Linksys E4200 Wireless-N

  8. Manual Steps to Setup Any Model Of Linksys Routers

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Wide Area Networks (WAN) Tutorial

Wide Area Networks(WAN) covers a large area extends from countries to continents. It is used to connect LANs together. It is like when we need to connect two LANs at different locations separated by a long distance, we need WAN to connect them. There are different WAN services used to connect different LANs situated at different locations. Cable and DSL are two most popular WAN connections. Other than these two, there is a list of WAN services available.

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 Used 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 use dedicated connections but it can connect multiple devices by a single device using 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 different devices.

Recommended Readings
  1. What is Local Area Network (LAN)

  2. How to Improve Internet Connection Speed

  3. What is Metropolitan Area Network (MAN)

  4. Basics of Computer Networking

Networking Devices Used in WAN

Important networking devices used in Wide Area Networks are:
  1. DSL and Cable Modems

  2. Firewall

  3. Carrier Switches

  4. NT1s

  5. Routers

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Metropolitan Area Network (MAN)

Metropolitan Area Networks in short MAN usually covers the area of a metropolitan city and is a hybrid between LAN and WAN. This type of networks covers a few kilometers. Cable TV network is an example of Metropolitan Area Network. But there is a difference. MAN is a computer network but cable TV connection provides TV broadcast. In a Metropolitan Area Network, two buildings in a city is connected and start data transfer. That means this connect two devices which are located far away but limited to a metropolitan location. It has the size of a metropolitan city. 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 specified in the IEEE 802.6 standard. Using DQDB, networks can be up to 30 miles length 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

Other Networks
  1. Local Area Networks (LAN)

  2. Wide Area Networks (WAN)

  3. Wireless Networks

  4. OSI Layers

Network Portal

Basics of Computer Networking

A network consists of all devices connecting each other in order to communicate between them across a small or large distances. 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 in to 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 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 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 components 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 is 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.
    How to Enable Wireless Adapter

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Local Area Network (LAN) -CCNA Study Material

Local Area Network(LAN) is used to connect networking devices in a small area like an office or campus building. The media type used to connect devices in a Local Area Network(LAN) are Ethernet, FDDI, Token Ring etc. LAN helps to communicate between devices in a smaller area and improve the efficiency of working of an office. Let us consider common topologies used in Local Area Network because it is in CCNA Exam Syllabus. It is classified in to 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 are communicating.

LAN Physical Topologies
  1. Point to Point

    Here two devices are connected without any any interference from other devices. In this LAN topology these two devices are connected and communicated. Wireless Bridge is a good example of Wireless Point to Point Topology.
    How to Configure Linksys WAP54G in to Wireless Bridge Mode

  2. Bus T

    You can say it is an extension of Point to Point topology because in Bus topology all devices in LAN are connected to single connection. Ethernet uses Bus topology.

  3. Ring

    If a Local Area Network has Ring Topology all devices are connected in a way to form a ring. It means PC 1 is connected to PC 2 and PC 2 is connected to PC 3 and the last PC is connected to PC 1. So it forms a ring structure. One example for LAN ring topology is FDDI.

  4. Star

    In start topology all devices in a LAN are connected to the central device. Example is all the computers connected to a Switch.

LAN Logical Topologies
  1. Bus

    Ethernet is an example which is using logical bus structure to communicate devices connected. To learn more about Ethernet, visit the link below.
    Fundamentals of Ethernet

  2. Ring

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

Medium of Transmission in LAN
  1. Twisted-pair wire

  2. Coaxial cables

  3. Fiber optic cables

Other Network Tutorials
  1. Metropolitan Area Network(MAN)

  2. Wide Area Network (WAN)

  3. How to Improve The Speed Of Your Internet Connection

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