Transcript Networking and communication

THE NETWORKS
Theo Chakkapark
Open System Interconnection
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The tower of power!
The source of this power comes
from the model’s flexibility
Network Topologies
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Ring
Network Topologies
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Bus
Network Topologies
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Star
TCP/IP protocol
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Internet uses
TCP/IP protocol
Internet Addressing
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IP Address
Internet Addressing
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Port
TCP/IP Protocol Suite: Encapsulation
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It’s kinda like Tetris(TM)!
Domain Name System
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Sorta like the yellow pages, but for the internet
Networking Equipment
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Repeaters are like the Verizon Guy, they never shut
up, but that’s a good thing in networking
Networking Equipment
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Hubs
Networking Equipment
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Switch
Networking Equipment
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Router
END
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NO MORE PAST THIS POINT
Serious stuff here
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OSI Model
 Highest
level is the application layer, provides
interface to allow applications to communicate with
each other over network
 Presentation layer ensures that data is presented to
communication applications in a common format (ie
delivers data in big/little endian format)
 Session layer establishes/terminates communication
sessions between host processes; maintains integrity of
communication even if layers below lose data
Serious stuff here
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OSI Model Continued
Transport layer ensure reliable transmission from the source
to destination and creates communication resources so data
is transferred quickly and effectively; provides error
recovery
 Network layer routes data through systems and
subnetworks, which consists of a topology, or connectivity
among network components
 Data-link layer manages direct connections between
components on the network
 Physical layer ensures that the raw data is transmitted from
a source to a destination over the physical medium; transmits
and repeats signals across network boundaries
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Serious stuff here
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Topologies
 Bus:
Components connected through a single cable that
runs the network
+
Each component can communicate directly with any other
component on the bus, and easy to add new components
 - Length limit on cabling, breaks in cable can disrupt the
network
 Ring:
Uses single cable, where the ends are jointed.
Packets pass around the ring until they reach
destination
Serious stuff here
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Topologies Cont.
 Star:
 The
Each component is connected to a central hub
hub receives data from one component and forwards it
to all other components, leaving it to the individual
components to determine whether or not they are the target
 + Most of the network service, troubleshooting, and wiring
changes are done on the central hub
 - Problems with the hubs affects the entire network
 - Requires more cabling than a bus or ring
Serious stuff here
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IP Addresses
 IP
addresses are like an apartment address
 Ports are like the individual unit numbers in an
apartment
 Data has an IP address and a port, so it knows where
to travel to
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DNS = Domain Name System
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Like a phone book: Domain names are looked up in
DNS, and translated to an IP destination
Serious stuff here
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TCP/IP Protocol
 At the application layer, a process can exchange data with
another process anywhere on the internet and treat the
connection as if it were a file on the local system
 The network layer deals with hop-by-hop communication
 The transport layer deals with end-to-end communication;
uses Transmission Control Protocol (TCP)
 The link layer is responsible for getting frames of bits from
one machine to another
Serious stuff here
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TCP/IP Encapsulation
 User data is sent from the application layer to the
transport layer
 The OS adds a TCP header that identify the source and
destination ports, forming a TCP segment, and sends that to
the network layer
 In the network layer, an IP header identifying the source
and destination systems are added, which gets sent to the
link layer
 The link layer appends information that allows this data to
pass through a medium, such as ethernet, or ADSL
Serious stuff here
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Repeaters regenerate or amplify electrical signals in the
network
 Hubs propagate data through the network without regard
to the actual destination; it sends it through the ENTIRE
network
 Switches are an intelligent hub, where it can send data to
an intended destination without sending it to other
computers
Routers bridge networks together; differs from switch in that a
switch forwards based on destination address, while a router
forwards packets based on protocol