Thursday, 21 February 2013
Monday, 18 February 2013
OSI Reference Model
The OSI Model consists of the following seven layers:
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The main use of the model is to help network designers understand the
functionality involved with the development and flow of data
communications. Included within this model are the protocols for network
properties and transmission methods.
The model is divided into 7 layers, with individual characteristics and
tasks within each layer. Each layer must communicate with the layer
directly above and below through a series of standards and
protocols.
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Thursday, 7 June 2012
DCN GTU Question
GTU
Exam Dec. - 2011
Subject:
Data Communication and Network Date:
07/12/2011
Question
-3 (b) 5 Mrks
What is IP Address? Explain different class of IP address and find the
class of following IP address:
192.168.1.5
Answer
IP address:
Internet
Protocol Address (or IP Address) is 32 bit an unique address that
computing devices use to identify itself and communicate with other devices in
the Internet Protocol network. Any device connected to the IP network must have
an unique IP address within its network.
Class of IP
address:
IP
addressing supports five different address classes: A, B,C, D, and E. Only
classes A, B, and C are available for commercial use.
From
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To
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Class – A
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0.0.0.0
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127.255.255.255
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Class – B
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128.0.0.0
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191.255.255.255
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Class – C
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192.0.0.0
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223.255.255.255
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Class – D
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224.0.0.0
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239.255.255.255
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Class - E
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240.0.0.0
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255.255.255.255
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•
Class A
–
In class-A first number is network Id (N.H.H.H).For
example in IP address: 4.22.145.90
number - 4 is network Id.
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In class-A 0 not be used as Net ID.
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In class-A total 126 different network generate
from 1-126.
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127 is reserved for loop back functions.
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Total 16,777,214 Hosts per one network and total
126 x 16,777,214 host in class – A.
•
Class B
–
In class-B first two numbers is network Id (N.N.H.H).
For example in IP address: 129.6.8.4
number – 129.4 is network Id.
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The rang of class – B is 128-191.
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The first IP Address is the NET ID.
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The last IP Address is the Broadcast Address
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In class – B 16,384 Different Networks
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Total 65543 Hosts per one network
•
Class C
–
In class-C first three numbers is network Id
and last is hostid(N.N.N.H). For example in IP address: 197.76.9.23 number – 197.76.9 is network
Id.
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The rang of Class – C is 192-223
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The first IP Address is the NET ID
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The last IP Address is the Broadcast Address
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In class – C 2,097,152 Different Networks
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254 Hosts per Network
•
CLASS D – Used for multicast broadcasts
- CLASS E – Experimental addresses not available to the public
IP address: 192.168.1.5 is in Class – C because
first number 192 in range of class – C.
Note: This also topic-1 of Chapter-7
Friday, 4 May 2012
Sunday, 22 April 2012
Function of Repeater with Advantage and Disadvantage
Ø A repeater is the simplest facility used for network
interconnection.
Ø The major function is to receive a network signal from one
LAN terminal cable segment and to regenerate and retransmit the signal as it is
in its original strength over a one or more other cable segment.
Ø Basically repeater regenerates the strength of the signal
before transmitting it.
Ø Repeaters operate in the OSI model Physical
layer and are transparent to all the protocols operating in the
layers above the Physical layer.
Ø Repeaters allow a network to be constructed to exceed the
size limit of a single, physical, cable segment.
Ø The number of repeaters that can be used intended is
generally limited by a particular LAN implementation. Using a repeater between
two or more LAN cables segment requires that the same physical layer protocol
be used to send signal over all the cable segments.
Advantages of a repeater
- · Simple to connect
- · Cost effective
- · Ability to strengthen signal
Disadvantages of a repeater
- · Repeaters provide no method for isolating traffic generated on one cable segment from traffic generated by the other cable segment.
- · When network uses a repeater to connect cable segment A to segment B whether or not there is a station in segment B that is the destination of the signal.
Thursday, 12 April 2012
How to start ASP.Net with Visual Studio 2008
Step:
1 Click on Start --> Microsoft Visual
Studio 2008
Step: 2 Click on File --> New --> Web Site
Step: 4 It open your first web site in Source mode.
Step: 2 Click on File --> New --> Web Site
It
open new window.
Step:
3 In new window set Language : Visual C#
set path :
C:\ASP.Net\WebSite1
click Ok
Step: 4 It open your first web site in Source mode.
Now click on Design mode it
open blank page.
