25-06-2012, 12:57 PM
Seminar on Network and Communication
[attachment=25399]
Transmission links
Convey bits, bytes, packets
Physical medium
Copper (or aluminium)
Optical fibre
Glass, plastic
Free-space optical
Laser
Radio
Satellite, microwave link, mobile, wireless LAN, ‘Bluetooth’
Mode
Point-to-point
Shared medium (multicast)
Broadcast
Representing data: bits and bytes
Bits
Different codes used in different interface standards
Images, multi-media
Require special bit pattern as delimiter
Bytes
Text is usually ASCII or Unicode characters
Text files, documents
Character set includes special control characters
Representing data: Frames
A block of data is called a frame
Basic unit of transfer between switches
Main purpose of frame is to carry packets from one point to another on a network
Header carries
Addressing (usually rather low level)
Control information for receiving network device (host/network node)
Trailer (if present) carries error check
Used for detecting errors in received frame
Block sizes restricted by buffer sizes in the network device interfaces
Representing data: Packets
Blocks of application data with some networking routing information
Basic unit of transfer between routers
Header carries
Network-wide addressing information
Control information for receiving network device (host, router)
No information is appended to a packet
There is no trailer, as there is with frames
In theory, packets can be quite large
Types of network
Main types:
LAN, WAN, MAN, and Internet
LAN (Local Area Network) is mainly private
Ether net, Token ring
Or interconnected
WAN (Wide Area Network) can be private or public
Interconnected
MAN (Metropolitan Area Network) is mainly public
Interconnected by Optical fibre
Global Network is public
The internet
The telephone network
OSI: The International Standards Model
Created in the 1980s by the standards bodies
ISO, ITU-T(Telecommunication Standardization Sector) , IEEE
Contributors included people from all sectors of the industry, government and academia
Designed originally to overcome the problems of non-interoperability between different manufacturers’ computers
Is a protocol suite
A set of interdependent layer functions
A set of interdependent protocols
Ten years of development rendered it too complex to be of real practical use, however, we still use
Most of the Layer names
Some of the terminology
[attachment=25399]
Transmission links
Convey bits, bytes, packets
Physical medium
Copper (or aluminium)
Optical fibre
Glass, plastic
Free-space optical
Laser
Radio
Satellite, microwave link, mobile, wireless LAN, ‘Bluetooth’
Mode
Point-to-point
Shared medium (multicast)
Broadcast
Representing data: bits and bytes
Bits
Different codes used in different interface standards
Images, multi-media
Require special bit pattern as delimiter
Bytes
Text is usually ASCII or Unicode characters
Text files, documents
Character set includes special control characters
Representing data: Frames
A block of data is called a frame
Basic unit of transfer between switches
Main purpose of frame is to carry packets from one point to another on a network
Header carries
Addressing (usually rather low level)
Control information for receiving network device (host/network node)
Trailer (if present) carries error check
Used for detecting errors in received frame
Block sizes restricted by buffer sizes in the network device interfaces
Representing data: Packets
Blocks of application data with some networking routing information
Basic unit of transfer between routers
Header carries
Network-wide addressing information
Control information for receiving network device (host, router)
No information is appended to a packet
There is no trailer, as there is with frames
In theory, packets can be quite large
Types of network
Main types:
LAN, WAN, MAN, and Internet
LAN (Local Area Network) is mainly private
Ether net, Token ring
Or interconnected
WAN (Wide Area Network) can be private or public
Interconnected
MAN (Metropolitan Area Network) is mainly public
Interconnected by Optical fibre
Global Network is public
The internet
The telephone network
OSI: The International Standards Model
Created in the 1980s by the standards bodies
ISO, ITU-T(Telecommunication Standardization Sector) , IEEE
Contributors included people from all sectors of the industry, government and academia
Designed originally to overcome the problems of non-interoperability between different manufacturers’ computers
Is a protocol suite
A set of interdependent layer functions
A set of interdependent protocols
Ten years of development rendered it too complex to be of real practical use, however, we still use
Most of the Layer names
Some of the terminology