January 2019

Tuesday 22 January 2019

Wireless Networking

Million Things 09:28 Network No comments :

Wireless Network

Wireless Network means that network which has not need any wire for communication or which can transfer data and files wirelessly. In networking terminology, wireless network can be define as to any computer network where there is no requirement of physical wired connection between sender and receiver, but rather the network is connected by radio waves or by microwaves to maintain communication. Wireless networking specific equipment are used such as NICs, APs and routers in place of wires for connectivity and which give same or high speed .

Some Wireless Technology

Infrared Technology

Mobile phone

Wi-Fi

Bluetooth

Radio frequency

Types Of Wireless Network

WLANS: Wireless Local Area Networks

wireless LANs use radio frequencies that are radiated into the air from an antenna that creates radio waves. These waves can be absorbed,refractedor reflected by walls,water or also by any metal surfaces because of that it resulting in low signal strength.It means it got affected by surrounding environment.WLANS is temporary network can be formed by a small number of users without the need of an access point; given that they do not need access to network resources.

WPANS: Wireless Personal Area Networks

The two current technologies for wireless personal area networks are InfraRed (IR) and Bluetooth (IEEE 802.15). These will allow the connectivity of personal devices within an area of about 30 feet. However, IR requires a direct line of site and the range is less.

WMANS: Wireless Metropolitan Area Networks

This technology allows the connection of multiple networks in a metropolitan area such as different buildings in a city, which can be an alternative or backup to laying copper or fiber cabling.

WWANS: Wireless Wide Area Networks

These types of networks can be maintained over large areas, such as cities or countries, via multiple satellite systems or antenna sites looked after by an ISP. These types of systems are referred to as 2G (2nd Generation) systems.

Wi-Fi

Wi-Fi is a wireless networking device thats gives a wireless network between computers and other devices to communicate . It describes network components that are based on one of the 802.11 standards developed by the IEEE and adopted by the Wi-Fi Alliance. Examples of Wi-Fi standards, in chronological order, include:

Standard Maximum speed

802.11a 54Mbps

802.11b 11Mbps

802.11g 54Mbps

802.11n 150Mbps

802.11ac 800Mbps

Thursday 17 January 2019

Network Devices (Hub,Switch,Lan card,Bridge,Router)

Million Things 08:15 Network No comments :

NETWORK DEVICES

Network devices provide connectivity and functionality.By understanding how these networking devices operate and identifying the functions they perform are essential for users.Some of the major network devices are discussed below.

Types are of following types

1.HUB

A hub is a common connection point for devices in a network. Hubs are commonly used to connect segments of a LAN. A hub contains multiple ports. When a packet arrives at one port, it is copied to the other ports so that all segments of the LAN can see all packets.

1 Hub sends the data in broadcast mode

2 It works on data link layer

Two types are:-

1 Active hub-needs adapter.

2 Passive hub-needs batteries.

What Hubs Do

Hubs and switches serve as a central connection for all of your network equipment and handles a data type known as frames. Frames carry your data. When a frame is received, it is amplified and then transmitted on to the port of the destination PC.

In a hub, a frame is passed along or "broadcast" to every one of its ports. It doesn't matter that the frame is only destined for one port. The hub has no way of distinguishing which port a frame 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.

2. SWITCH

In networks, a device that filters and forwards packets between LAN segments. Switches operate at the data link layer (layer 2) and sometimes the network layer (layer 3) of the OSI Model .

1 looks much like a hub.

2 expensive than hub.

3 has more advantages than hub

Types of switch

1)lan switch -mostly used in local connectivity.

2)wan switch-wan connectivity.

3)atm switch-asynchronous transfer mode

It is used for calling functionality.it allows voice and data networks with a single networks to handle.

Types are

1.) non-manageable switch

2.) manageable switch

3.Lan card-

A network interface controller (NIC, also known as a network interface card, network adapter, LAN adapter or physical network interface,and by similar terms) is a computer hardware component that connects a computer to a computer network.

Types of nic card-

1.on board

2.Expansion board

Wednesday 16 January 2019

SUBNETTING

Million Things 08:58 Network No comments :

What is Subnet

A subnetwork, or subnet, is a logical, visible subdivision of an IP network. The practice of dividing a network into two or more networks is called subnetting.

ADVANTAGES à

1.Find out wasted IP Address.

2.To provide security or block IP communication with each other.

3.Used for find out waste ip and broadcast ip ,this Ip address slow down the whole network.

4.Used for logical boundary.

SUBNET MASK

WHAT IS SUBNET MASK?

-IT DIFFERENTIATES NETWORK PORTION AND HOST PORTION IN AN IP.

-IT IS GIVEN FOR HOST ID OF NETWORK ID.

-REPRESENTS ALL NETWORK BITS WITH 1 AND 0 FOR ALL THE HOST BIT.

>>CLASS A:--N.H.H.H

DEFAULT S/M OF A

255.0.0.0

11111111.00000000.00000000.00000000

>>CLASS B:--N.N.H.H

DEFAULT S/M OF B

255.255.0.0

11111111.11111111.00000000.00000000

>>CLASS C:--N.N.N.H

DEFAULT S/M OF C

255.255.255.0

11111111.11111111.11111111.00000000

CALCULATING SUBNETTING

(by six formulas)

1.identify the class of ipaddress,and write down “extra on bits.

2.calculate new subnet mask.

3.calculate block size

[256-new s/m]

4.calculate no. of network

[2ⁿ(n=extra on bits)]

5.calculate no.of pc/network

[2^H(H=off bits)]-2

6.make the table

OSI Model

Million Things 08:43 Network No comments :

WHAT IS OSI LAYER?

OSI means OPEN SYSTEM INTERCONNECT model or layer.it means every System is open to connect with other.

# Developed by ISO (INTERNATIONAL ORGANIZATION FOR STANDARDIZATION)

IN 1974.

#It consist of seven layer.

#Each layer has a different but specific processing function.

Layer 7>>APPLICATION

Layer 6>>PRESENTATION

Layer 5>>SESSION

Layer 4>>TRANSPORT

Layer 3>>NETWORK

Layer 2>>DATA LINK

Layer 1>>PHYSICAL

7.)APPLICATION LAYER

it provides networking services to user.

It also known as desktop layer.

protocols like dhcp,http,webbroweretc are used in this layer.

6.) PRESENTATION LAYER

It converts data into standard formats for to receive or transmit.

(American standard code for information interchange)

e.g.>>ASCII,JPEG,BMP,MP3 etc.

following tasks are done in this layer

ENCODING – DECODING

ENCRYPTION - DECRYPTION

5.) SESSION LAYER

It is responsible for establishing,maintenance,and terminating session.

SESSION ID WORKS IN THIS LAYER.

E.G.-

RPCàREMOTE PROCEDURE CALL

SQLàSTRUCTURED QUERY LANGUAGE

NFSàNETWORK FILE SYSTEM

4.)TRANSPORT LAYER

IT maintains END TO END connectivity.

It is the heart of OSI LAYERS.

Two protocols works in this layer they are-

1. TCP (TRANSMISION CONTROL PROTOCOL)

2. UDP (USER DATAGRAM PROTOCOL)

FOLLOWING TASKS ARE DONE HERE

# IDENTIFYING SERVICES.

# MULTIPLEXING & DE-MUX.

# SEGMENTATION.

# SEQUENSING & REASSEMBLING.

# FLOW CONTROL.

# ERROR CORRECTION.

3.)NETWORK LAYER

IT provides best path for data to reach destination.

Logical addressing is done on this layer.

Device works on this layer is router.

It is divided into two parts

1. routed protocols

e.g. ip,ipx,apple talk etc.

2. routing protocols

e.g. rip >routing information protocol

ospf>open shortest path first

igrp>integrated gateway routing protocol

eigrp>enhance igrp

2.) DATA LINK LAYER

It is divided into two sub layers.

1. LLC –LOGICAL LINK CONTROL

WAN protocols works here.provides error-free data from one node to other node.

e.g. ppp(point to point protocol),hdlc(high level data link control).

2. MAC – MEDIA ACCESS CONTROLLER.

It talks about physical address.

1.)PHYSICAL LAYER

It talks about electrical,mechanical or procedural checks.

Co-axial or twisted pair cable> data will be in electrical pulse or e- form.

Fiber optic cable>>data will be in light form.

Devices works in this are>>

ethernet

Hubs (active & passive)

Cables

repeaters

connectors

Topology

Million Things 08:19 Network No comments :

Whats is Topology

A network topology refers to the physical arrangements or the network layout in which all the devices are interconnected to communicate on the network. It defines manner in which cables are arranged.

There are two types of topologies

1. Physical

It refers to configurations of cables, computers and other peripherals.

2. logical

It bounds to the network protocol which directs the data transfer across a network.

Types of physical topologies

ž (01) Bus

ž (02) Ring

ž (03) Star

ž (04) Mash

ž (05) Hybrid

BUS TOPOLOGY

-A linear bus topology consists of a main run of cable with a terminator at each end.

-All nodes (file server, workstations, and peripherals) are connected to the linear cable

-žIt is use T connector:

Advantages of BUS Topology

-žEasy to connect a computer or peripheral to a bus.

-žRequires less cable length than a star topology.

-žEasy to transfer.

Disadvantages of BUS Topology

-if backbone cable is not work properly whole network is shut down.

-Terminators are required at both ends of the backbone cable.

-žHigh collision.

-Always broadcast.

RING Topology

-žRing topology, pc are connecting like ring.

-žIn a ring topology network computers are connected by a single loop of cable,

-žRing topology is an active topology because each computer repeats (boosts) the signals.

-žIf there is a line break, or if you are adding or removing a device anywhere in the ring this will bring down the network.

-žData is sending through token passing method.

What is network and its types

Million Things 06:14 Network No comments :

COMPTIA N+

Computing Technology Industry Association

CompTIA Network+ is a vendor neutral networking certification that is trusted around the world. It validates the essential knowledge and skills needed to confidently design, configure, manage and troubleshoot any wired and wireless devices. CompTIA Network+ certified individuals are in-demand worldwide.

What is network ?

A network is a collection of multiple computers or

Other hardware devices that are connected together, either physically or logically using hardware and software.

What is networking?

Networking is the process of sharing of data between different devices,and it also involves

Designing, implementing, upgrading ,managing and working with network technologies.

Types of network

1. (Lan) Local area network

2. (man) metropolitan area network

3. (Wan) wide area network

4. (Can ) campus area network

5. (Gan) global area network

6. (Pan) personal area network

Local Area Network

A computer network that links devices within a building or group of adjacent buildings, especially one with a radius of less than 1 km.

Metropolitan Area Network

A metropolitan area network (MAN) is a network that interconnects users with computer resources in a geographic area or region larger than that covered by even a large local area network (LAN) but smaller than the area covered by a wide area network (WAN).

Wide Area Network

A WAN (Wide Area Network) is a communications network that spans a large geographic area such as across cities, states, or countries. WANs often link multiple smaller networks together including local area networks (LANs) or metro area networks (MANs).