Information Technology Institute

volleyballbeginnerNetworking and Communications

Oct 27, 2013 (3 years and 9 months ago)

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Ministry of
Communications and
Information Technology

Information Technology
Institute

Information Technology Institute

Network Fundamentals

Introduction to Internet

Lec
2

What is the Internet?


Internet Origin and History


Who Owns the Internet?


Internet Connections

Internet development in Egypt:


historical background


1993

via a
9.6K

link between the Egyptian
Universities Network and France


1994

the Egyptian domain was divided into three
major subdomains


sci.eg


com.eg


gov.eg


Provide
64K

digital access to France


Internet Gateway in Egypt

Who owns the Internet?


No one actually owns the Internet


Many Orgs, ISPs, Companies, Govs own pieces of
Internet Infrastructure.


But many organization oversee.


ISOC
Internet Society


IETF

Internet Engineering Task Force

Network Communicating Protocols

The Need for Protocols


Protocols are needed for computer networks to
communicate efficiently



Network protocols are set of rules that enable data
to flow from one NIC to another



Protocols control the messages origination, the
messages end, and the messages quantity in the
network.



Major Networking Protocols


NetBEUI


IPX/SPX


TCP/IP


AppleTalk


NetBIOS


Network Basic Input/Output System.



A common network protocol that allows
applications on different computers to
communicate within a local area network
(LAN).




It was created by IBM for its early PC
Network, and was adopted by Microsoft.




It does not support a routing mechanism.



NetBIOS was later formalized in NetBEUI.


NetBEUI


NetBIOS Extended User Interface.



This is an enhanced version of the NetBIOS
protocol used by network operating systems
(NOS), such as Microsoft's Windows NT.



NetBEUI was developed by IBM for its LAN
Manager product and has been adopted by
Microsoft for its Windows NT, LAN Manager,
and Windows for Workgroups products.



Non
-
routable

NetBEUI Advantages and
Disadvantages


Advantages


High speed on small networks


ease of implementation


small memory overhead


Self tuned (does not need configuration)



Disadvantages


It cannot be routed between networks.


IPX/SPX


Internet Packet Exchange Sequenced Packet
Exchange.



A communications protocol devised by Novell
for Novell NetWare.



IPX/SPX packets can be routed from one
network to another

IPX/SPX Advantages and
Disadvantages


Advantages


Ease of setup.


Support for routing between networks.


Speeds greater than TCP/IP for NT.



Disadvantages


Slower than NetBEUI.


IPX/SPX is not a vendor neutral


TCP/IP


Transmission Control Protocol/Internet
Protocol.


TCP/IP is open standard protocol


Not tied to one vendor


TCP/IP is the internet protocol


Now internet use TCP/IP v4


Next version TCP/IP v6


It is the default protocol for


Windows NT4


Windows 2000


UNIX

TCP/IP Advantages and
Disadvantages


Advantages


Broad connectivity among all types of computers and
servers


Direct access to the Internet



Disadvantages


Difficulty of setup


Slower than IPX & NetBEUI


AppleTalk


AppleTalk is a set of local area network
communication protocols originally created
for Apple computers. An AppleTalk network
can support up to 32 devices and data can be
exchanged at a speed of 230.4 kilobits per
second (Kbps).

OSI Reference Model


OSI:
O
pen
S
ystems
I
nterconnection



The OSI model is the primary architectural model for
networks.



It describes how data and network information are
communicated from an application on one computer,
through the network media, to an application on
another computer.



The model was defined by the International
Organization for Standardization (ISO)



The OSI reference model breaks this approach into
layers.

Advantages of Reference Models


It divides the network communication process into
smaller and simpler components, thus aiding component
development, design, and troubleshooting.



It allows multiple
-
vendor development through
standardization of network components.



It encourages industry standardization by defining what
functions occur at each layer of the model.



It allows various types of network hardware and software
to communicate.



It prevents changes in one layer from affecting other
layers, so it does not hamper development.

OSI Seven Layers


Application


Presentation


Session


Transport


Network


Data Link


Physical

What should I send?


End
-
user Interface


Where client applications reside


Displays received information


Sends user’s data to lower layers


Application Layer

Presentation Layer


The presentation layer is responsible for the delivery and
formatting of information to the application layer for further
processing or display.


It relieves the application layer of concern regarding
syntactical differences in data representation within the
end
-
user systems.


An example of a presentation service would be the
conversion of an EBCDIC
-
coded text file to an ASCII
-
coded file.

Close

Connection

You are

welcome!

Thank you.

I would like to

send you

something.

Sounds

good!

Establish

Connection


Controls the sessions between the local and
remote applications

Session Layer

Transport Layer


There is services that can be optionally provided at this
layer:



Connection
-
Oriented


Same Order Delivery


The simplest way of doing this is to give each packet a
number, and allow the receiver to reorder the packets.


Reliable Data


Flow Control


Without flow control a computer might be flooded with so
much information that it can't hold it all before dealing with it.

Network Layer


Organize data into
datagrams

(packets)


Addresses messages


Routing


Provides the functional and procedural means of transferring
variable length data sequences from a source to a destination via
one or more networks

Data Link Layer


Reliable data transfer across a physical link


It provides the means to detect errors that may occur in the
Physical layer.


Organize the data into frames, to be put on the physical
medium


Transfers data between adjacent network nodes


The data link layer is split into MAC and LLC
sublayers


Physical Layer


The Physical layer defines all the electrical and physical
specifications for devices.



The physical layer is the most basic network layer,
providing only the means of transmitting raw bits.

The Internet Protocol

TCP/IP Protocol Suite

TCP/IP Protocol Suite


Specified and extensively used before the OSI model


Developed by research funded US Department of Defense


Used by the Internet

TCP/IP Protocol Suite

Addressing

Layers and Addresses in TCP/IP

Physical addresses

IP addresses

Port addresses

Where do I go?

Provides physical
routing information

Network Layer Addressing

IP Address


255

255


255


255

Dotted

Decimal

Maximum

Network

Host

32
Bits

IP Addressing


255

255


255


255

Dotted

Decimal

Maximum

Network

Host

128

64

32

16

8

4

2

1



11111111


11111111


11111111


11111111

Binary

32 Bits

1

8

9

16

17

24

25

32

128

64

32

16

8

4

2

1


128

64

32

16

8

4

2

1


128

64

32

16

8

4

2

1


Decimal Equivalents of Bit Patterns

0

0

0

0

0

0

0

0

=

0

1

0

0

0

0

0

0

0

=

128

1

1

0

0

0

0

0

0

=

192

1

1

1

0

0

0

0

0

=

224

1

1

1

1

0

0

0

0

=

240

1

1

1

1

1

0

0

0

=

248

1

1

1

1

1

1

0

0

=

252

1

1

1

1

1

1

1

0

=

254

1

1

1

1

1

1

1

1

=

255

128

64

32

16

8

4

2

1

IP Address Classes


Class A:


Class B:


Class C:


Class D:


Multicast


Class E:

Research

Network

Host

Host

Host

Network

Network

Host

Host

Network

Network

Network

Host

8
Bits

8
Bits

8
Bits

8
Bits

IP Address Classes

1

Class A:

Bits:

0
NNNNNNN

Host

Host

Host

8

9

16

17

24

25

32

Range (
1
-
126
)

1

Class B:

Bits:

10
NNNNNN

Network

Host

Host

8

9

16

17

24

25

32

Range (
128
-
191
)

1

Class C:

Bits:

110
NNNNN

Network

Host

8

9

16

17

24

25

32

Range (
192
-
223
)

1

Class D:

Bits:

1110
MMMM

Multicast Group

Multicast Group

8

9

16

17

24

25

32

Range (
224
-
239
)

Network

Network

Network

Network

Network

Network

Network

Network

Multicast Group

Multicast Group

Multicast Group

Multicast Group

Multicast Group

Multicast Group

Thank you