1. It refers to the way a network is laid out
physically or logically
2. Describes how the devices in the network
are interconnected
3. Five basic topologies.> Mesh,Star,Tree,
Bus, & Ring
4. Peer to peer & primary -secondary
Sunday, June 24, 2007
Line Configuration
It is the way two or more communication devices attach to a link.
A Link is the physical communication pathway that transfer data from one device to another.
Point to Point
Provide dedicated link between two devices
use actual length of wire or cable to connect the two end
including microwave & satellite link.
Infrared remote control & tvs remote control
Multipoint.
Also known as Multidrop line
configuration
one or more than two specific
devices share a single link
capacity of the channel is
shared
A Link is the physical communication pathway that transfer data from one device to another.
Point to Point
Provide dedicated link between two devices
use actual length of wire or cable to connect the two end
including microwave & satellite link.
Infrared remote control & tvs remote control
Multipoint.
Also known as Multidrop line
configuration
one or more than two specific
devices share a single link
capacity of the channel is
shared
De Facto Standard
More Examples
Xmodem Communications Protocol
Hewlett-Packard Printer Control Language (PCL) for laser printers
PostScript page description language for laser printers
De Jure
- Proprietery
standard that originally invented by a commercial organization as a basic
for an operation of its product.
De Jure
- Non Proprietery
developed by a group of committee that have been into public domain
Xmodem Communications Protocol
Hewlett-Packard Printer Control Language (PCL) for laser printers
PostScript page description language for laser printers
De Jure
- Proprietery
standard that originally invented by a commercial organization as a basic
for an operation of its product.
De Jure
- Non Proprietery
developed by a group of committee that have been into public domain
What is Standard?
Standards
Standards are extremely important in the computer industry because they allow the combination of products from different
manufacturers to create a customized system. Without standards, only hardware and software from the same company could be used together.
In addition, standard user interfaces can make it much easier to learn how to use
new applications.
Standards are extremely important in the computer industry because they allow the combination of products from different
manufacturers to create a customized system. Without standards, only hardware and software from the same company could be used together.
In addition, standard user interfaces can make it much easier to learn how to use
new applications.
What is Protocol
PROTOCOLS The transfer of data is entirely dependent upon PROTOCOLS. A protocol is a set of rules that determines, at each instance in time, what is legal and illegal, and the meaning of any legal data.
Semantic And Syntax
A protocol defines what is communicated, when it is communicated
Protocol elements
- Syntax
structure or format of data,meaning the order in which they are presented
-Semantic
meaning of each section of bits how is a particular pattern to be interpreted & what action is to be taken based on the interpretation
-Timings
when data should be sent & how fast it can be sent
Protocol elements
- Syntax
structure or format of data,meaning the order in which they are presented
-Semantic
meaning of each section of bits how is a particular pattern to be interpreted & what action is to be taken based on the interpretation
-Timings
when data should be sent & how fast it can be sent
Protocol and standard
A protocol defines what is communicated, when it is communicated
Protocol elements
- Syntax
structure or format of data,meaning the order in which they are presented
-Semantic
meaning of each section of bits how is a particular pattern to be interpreted & what action is to be taken based on the interpretation
-Timings
when data should be sent & how fast it can be sent
Protocol elements
- Syntax
structure or format of data,meaning the order in which they are presented
-Semantic
meaning of each section of bits how is a particular pattern to be interpreted & what action is to be taken based on the interpretation
-Timings
when data should be sent & how fast it can be sent
Applications
Marketing & sales collecting - exchange & analyse data relating to customer sales such as teleshopping & online reservation
Financial services - foreign exchange & investment services and electronic fund transfer
Manufacturing - manufacturing processing CAD/CAM
Electronic Messaging- e-mail
Directory services - worldwide search operations
Information services - bulletin boards & data banks
EDI -allow bussiness information to be transferred without using paper
Teleconferencing-
Cellular telephone
Financial services - foreign exchange & investment services and electronic fund transfer
Manufacturing - manufacturing processing CAD/CAM
Electronic Messaging- e-mail
Directory services - worldwide search operations
Information services - bulletin boards & data banks
EDI -allow bussiness information to be transferred without using paper
Teleconferencing-
Cellular telephone
Network Criteria
Factors affecting network performance
to be considered if network to be effective and efficient
PERFORMANCE
CAN BE MEASURED AS TRANSIT TIME & RESPONSE TIME
depends on 4 characteristics
No of Users - user = 1/response time
Transmission medium- medium define the speed at which data travel through connection
Hardware - effect both speed & capacity
Software - well design s/w can speed up the process
Factors affecting network performance
to be considered if network to be effective and efficient
PERFORMANCE
CAN BE MEASURED AS TRANSIT TIME & RESPONSE TIME
depends on 4 characteristics
No of Users - user = 1/response time
Transmission medium- medium define the speed at which data travel through connection
to be considered if network to be effective and efficient
PERFORMANCE
CAN BE MEASURED AS TRANSIT TIME & RESPONSE TIME
depends on 4 characteristics
No of Users - user = 1/response time
Transmission medium- medium define the speed at which data travel through connection
Hardware - effect both speed & capacity
Software - well design s/w can speed up the process
Factors affecting network performance
to be considered if network to be effective and efficient
PERFORMANCE
CAN BE MEASURED AS TRANSIT TIME & RESPONSE TIME
depends on 4 characteristics
No of Users - user = 1/response time
Transmission medium- medium define the speed at which data travel through connection
NETWORK
Set of devices connected by media link
nodes can be a computer,printer or any device capable of sending and / or receiving data generated by other nodes on the network
links connecting often called communication channels
nodes can be a computer,printer or any device capable of sending and / or receiving data generated by other nodes on the network
links connecting often called communication channels
Basic Elements or Component
the message is the information (data) to be communicated consist of text, number, sound or video
The Sender sends a Message over the Medium to the Receiver.
Eg. Workstataion ,PC , tel. Handset, or video camera
The receiver is the device that receive the data or message
The medium for communication is very important because without the medium there cannot be any communication, and further, the nature of the medium determines the speed of communications.
Protocol set of rules that govern data communication
The Sender sends a Message over the Medium to the Receiver.
Eg. Workstataion ,PC , tel. Handset, or video camera
The receiver is the device that receive the data or message
The medium for communication is very important because without the medium there cannot be any communication, and further, the nature of the medium determines the speed of communications.
Protocol set of rules that govern data communication
FUNDAMENTALS OF DATA COMMUNICATION
DELIVERY
The system must deliver data to the correct destination
ACCURACY
the system must deliver data accurately
TIMELINESS
the system must deliver data in a timely manner.
Timely delivery - deliver data as they are produced
in same order without significant delay.
The system must deliver data to the correct destination
ACCURACY
the system must deliver data accurately
TIMELINESS
the system must deliver data in a timely manner.
Timely delivery - deliver data as they are produced
in same order without significant delay.
What Is Data
Numbers, characters, images, or other method of recording, in a form which can be assessed by a human or (especially) input into a computer, stored and processed there, or transmitted on some digital channel. Computers nearly always represent data in binary
Data on its own has no meaning, only when interpreted by some kind of data processing system does it take on meaning and become information.
People or computers can find patterns in data to perceive information, and information can be used to enhance knowledge. Since knowledge is prerequisite to wisdom, we always want more data and information.
1234567.89 is data.
"Your bank balance has jumped 8087% to RM1234567.89" is information.
"Nobody owes me that much money" is knowledge.
"I'd better talk to the bank before I spend it, because of what has happened to other people" is wisdom.
What Is Data Communication?
The transfer of data from one machine to another machine such that the sender and receiver both interpret the data correctly.
The exchange of data between two devices via some medium.
Communication include telephony, telegraphy, television which means communicating at a distance.
In computer information system data are represented by binary information or bits
( 0 ‘s & 1 ‘ s )
Data on its own has no meaning, only when interpreted by some kind of data processing system does it take on meaning and become information.
People or computers can find patterns in data to perceive information, and information can be used to enhance knowledge. Since knowledge is prerequisite to wisdom, we always want more data and information.
1234567.89 is data.
"Your bank balance has jumped 8087% to RM1234567.89" is information.
"Nobody owes me that much money" is knowledge.
"I'd better talk to the bank before I spend it, because of what has happened to other people" is wisdom.
What Is Data Communication?
The transfer of data from one machine to another machine such that the sender and receiver both interpret the data correctly.
The exchange of data between two devices via some medium.
Communication include telephony, telegraphy, television which means communicating at a distance.
In computer information system data are represented by binary information or bits
( 0 ‘s & 1 ‘ s )
Subscribe to:
Posts (Atom)
