By Pradip Paudyal

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24 Οκτ 2013 (πριν από 4 χρόνια και 14 μέρες)

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By

Pradip

Paudyal

What is the Internet?

A communication infrastructure

u
sefulness
is in exchanging
information

What is a protocol?


A protocol is a collection of rules and procedures for
two computers to exchange information



Protocol also defines the format of data that is being
exchanged

What is TCP/IP?


TCP/IP is a set of protocols developed to allow
cooperating computers to share resources across a
network.


TCP stands for “Transmission Control Protocol”


IP stands for “Internet Protocol”


They are Transport layer and Network layer
protocols respectively of the protocol suite


The most well known network that adopted
TCP/IP is Internet


the biggest WAN in the world

IP Addresses


It is the identification of a host or router in
the networks


It is data oriented protocol used for
communicating data across a packet
switched networks


IP
(Version 4) Addresses are 32 bits long


IPv6
addresses are 128 bits long


IPv4
Addresses






IP address has two parts i.e. Network ID
and
Host
ID


Network ID tells us the which NW the particular
PC belongs to.


Node/Host ID defines the unique deceives within a
network.


Number of bits allocated to specify network varies






18.
26.0.1

network

32
-
bits

host


IPv4 address: a 32
-
bit number, usually written in
dotted decimal form, that uniquely identifies an
interface of some computer


Host Address: another term for IP address


Network: a group of hosts, all of which have an
identical beginning position of their IP addresses.


Network Number: a 32
-
bit number that represent a
network and it cant be assigned as IP address of a host


Network address: another term for the network
number.


Broadcast address: a 32
-
bit number that is used to
address all hosts in the network. It cant be assigned as
an IP address of a host.

IP address cont….

Classes of IP address


It helps us to determine how the four bytes/ 32 bits IP
address is divided in to network and node ID


Different classes of IP address are used depending on
their size of network.


First 8 bits of IP address is enough to determine the
class of IP addresses.


IP address cont….

Few IP address that can not be used are


0.0.0.0: Refers to default route used by the IP in routing
table


127.0.0.0: reserved for loopback
.


IP address with all host bit set to “0” : It refers to actual
network itself e.g. 192.168.0.0


IP address with all host bit set to “1”: It refers to as
network broadcast address e.g. 192.168.255.255 is a class
C IP.


IP address with all bit set to “1”: Refers to broadcast
address e.g. 255.255.255.255

Subnet Mask and Sub
-
netting


Subnet: a group of hosts, all of which have an identical
portion of their IP addresses, a subnet differs from a
network in that a subnet is a further subdivision of a
network.


At least default subnet
-
mask must be used for every
class of IP address.


All the IP address which uses default subnet mask is
known as “Class full IP address”;


And the IP addresses which uses other than default
subnet mask by creating a subnet ID known as “Class
-
less IP addresses”


Network Mask

The default subnet mask are:


Class A: 255.0.0.0


Class B: 255.255.0.0


Class C: 255.255.255.0


8.20.15.1 = 00001000.00010100.00001111.00000001

255.0.0.0 = 11111111.00000000.00000000.00000000




-----------------------------------




net id | host id



netid

= 00001000 = 8

hostid

= 00010100.00001111.00000001 = 20.15.1


Class A
IP_Address

Class A
Mask


Sub
-
netting the networks help us to partition the
network in to a smaller network according to the need
of company which helps to reduce the traffic and hides
the complexity of the networks i.e. the process of
subdividing networks into smaller subnets.


Subnet mask: A 32
-
bit combination used to describe
which portion of an address refers to the subnet and
which part refers to the host.


Address mask: another term for a mask


Interface: A network connection.


Sub
-
netting

Understanding Sub
-
netting


Sub
-
netting allows you to create multiple logical
networks that exist within a single Class A, B, or C
network


When sub
-
netting, a third part of IP address
appears in the middle of the address

namely, the
subnet part of the address. The size of the network
part never shrinks.


Network (8)

Subnet (24
-
x)

Host

(x)

Class A

Network (16)

Subnet (16
-
x)

Host

(x)

Class B

Network (24)

Subnet (8
-
x)

Host

(x)

Class C

Sub
-
netting Examples

E.g.


192.168.0.5


255.255.255.0


-
default subnet mask

E.g. Sub
-
netting;

192.168.0.5 and 255.255.255.224

11000000. 10101000. 00000000.
000

00101

11 11 1 1 1 1. 11 1 111 1 1 . 1 1 11 1 1 1 1.
1 1 1
00000



Network ID



Subnet ID
Host ID


Here, 3 bit is borrowed from the host ID to create subnet ID.
Hence 2^3=8 different network can be created and 256/8=32
different host in each network and IP that can be used in
each network is 32
-
2=30


Sub
-
netting Examples cont….



Determing the
host per subnet



Remarks

Determining
Subnets

Low

High



ooo

oooo1

11110





192.168.0.1

192.168.0.30

0 and 31
can’t
be used

oo1

oooo1

11110





192.168.0.33

192.168.0.62




and so on







Examples


given a Class C network of 204.17.5.0 which has a
natural mask of 255.255.255.0, you can create subnets
in this manner:

204.17.5.0
-

11001100.00010001.00000101.00000000

255.255.255.224


1 1 1 1 1111.1 1 1 1 1 1 11.11 1 1 1 1 11.11100000






-------------------------
|sub|
----

With these three sub
-
net bits, it is possible to create
eight subnets



Sub
-
netting


With the remaining five host ID bits, each subnet can have
up to 32 host addresses:



204.17.5.0 255.255.255.224 host address range 1 to 30


204.17.5.32 255.255.255.224 host address range 33 to 62


204.17.5.64 255.255.255.224 host address range 65 to 94


204.17.5.96 255.255.255.224 host address range 97 to 126


204.17.5.128 255.255.255.224 host address range 129 to 158


204.17.5.160 255.255.255.224 host address range 161 to 190


204.17.5.192 255.255.255.224 host address range 193 to 222


204.17.5.224 255.255.255.224 host address range 225 to 254


Sub
-
netting


the mask of 255.255.255.224 can also be denoted as /27
as there are 27 bits that are set in the mask


For example, 204.17.5.32/27 denotes the network
204.17.5.32 255.255.255.224.

Introduction to

Heterogeneous Networks and

ALL
-
IP Networks


Next
-
generation Wireless Internet


Heterogeneous Networks


Including different access networks



GPRS, WLAN, MANET (mobile ad hoc)


Vertical/Horizontal handoffs


All
-
IP Architecture and Connectivity


Terminals with Software
-
Based Radio Interfaces

Example IP
-
based 4G/Next G/…

network


Next
-
generation Wireless Internet


All
-
IP Architecture

Advantages


Integrated voice and data stack at end devices


Simpler signaling architecture


Lower operations and network management cost


Disadvantages


IP headers waste wireless bandwidth


More complex terminals


Larger latency


Requires
QoS

support for packet voice

Integrated WLAN and Cellular Data

Networks


A cellular data network can provide relatively low
speed data service (up to 115.2Kbps with GPRS and
2Mbps with 3G system) over a large coverage area. On
the other hand, WLAN provides high
-
speed data
service (up to 11 Mbps with 802.11b and 54Mbps with
802.11a) over a geographically small area.


An integrated network combines these two kind of
data networks.


A kind of Heterogeneous Networks

Integration


UMTS (or GPRS) vs. WLAN


Coverage


UMTS (several kilometers) > WLAN (several hundred meters)


Data rate


WLAN (up to 54Mbps) > UMTS (up to 2Mbps when static) >
GPRS (up to 115.2K bps)


There is a strong need for interworking mechanism
between WLANs and cellular data networks

Integration of Heterogeneous

Networks


Scenario:

Integration, Connection/Mobility, Authentication,
End
-
to
-
End
QoS

Research Issues in Heterogeneous

Networks


Thank You……………………