COMMUNICATION NETWORK

General keyboard shortcuts

2009-10-05T09:24:00.000-07:00

Remember these keys when ur mouse is not working this is very helpful.

General keyboard shortcuts

* CTRL+C (Copy)
* CTRL+X (Cut)
* CTRL+V (Paste)
* CTRL+Z (Undo)
* DELETE (Delete)
* SHIFT+DELETE (Delete the selected item permanently without placing the item in the Recycle Bin)
* CTRL while dragging an item (Copy the selected item)
* CTRL+SHIFT while dragging an item (Create a shortcut to the selected item)
* F2 key (Rename the selected item)
* CTRL+RIGHT ARROW (Move the insertion point to the beginning of the next word)
* CTRL+LEFT ARROW (Move the insertion point to the beginning of the previous word)
* CTRL+DOWN ARROW (Move the insertion point to the beginning of the next paragraph)
* CTRL+UP ARROW (Move the insertion point to the beginning of the previous paragraph)
* CTRL+SHIFT with any of the arrow keys (Highlight a block of text)
* SHIFT with any of the arrow keys (Select more than one item in a window or on the desktop, or select text in a document)
* CTRL+A (Select all)
* F3 key (Search for a file or a folder)
* ALT+ENTER (View the properties for the selected item)
* ALT+F4 (Close the active item, or quit the active program)
* ALT+ENTER (Display the properties of the selected object)
* ALT+SPACEBAR (Open the shortcut menu for the active window)
* CTRL+F4 (Close the active document in programs that enable you to have multiple documents open simultaneously)
* ALT+TAB (Switch between the open items)
* ALT+ESC (Cycle through items in the order that they had been opened)
* F6 key (Cycle through the screen elements in a window or on the desktop)
* F4 key (Display the Address bar list in My Computer or Windows Explorer)
* SHIFT+F10 (Display the shortcut menu for the selected item)
* ALT+SPACEBAR (Display the System menu for the active window)
* CTRL+ESC (Display the Start menu)
* ALT+Underlined letter in a menu name (Display the corresponding menu)
* Underlined letter in a command name on an open menu (Perform the corresponding command)
* F10 key (Activate the menu bar in the active program)
* RIGHT ARROW (Open the next menu to the right, or open a submenu)
* LEFT ARROW (Open the next menu to the left, or close a submenu)
* F5 key (Update the active window)
* BACKSPACE (View the folder one level up in My Computer or Windows Explorer)
* ESC (Cancel the current task)
* SHIFT when you insert a CD-ROM into the CD-ROM drive (Prevent the CD-ROM from automatically playing)
* CTRL+SHIFT+ESC (Open Task Manager)

Dialog box keyboard shortcuts

If you press SHIFT+F8 in extended selection list boxes, you enable extended selection mode. In this mode, you can use an arrow key to move a cursor without changing the selection. You can press CTRL+SPACEBAR or SHIFT+SPACEBAR to adjust the selection. To cancel extended selection mode, press SHIFT+F8 again. Extended selection mode cancels itself when you move the focus to another control.

* CTRL+TAB (Move forward through the tabs)
* CTRL+SHIFT+TAB (Move backward through the tabs)
* TAB (Move forward through the options)
* SHIFT+TAB (Move backward through the options)
* ALT+Underlined letter (Perform the corresponding command or select the corresponding option)
* ENTER (Perform the command for the active option or button)
* SPACEBAR (Select or clear the check box if the active option is a check box)
* Arrow keys (Select a button if the active option is a group of option buttons)
* F1 key (Display Help)
* F4 key (Display the items in the active list)
* BACKSPACE (Open a folder one level up if a folder is selected in the Save As or Open dialog box)

Microsoft natural keyboard shortcuts

* Windows Logo (Display or hide the Start menu)
* Windows Logo+BREAK (Display the System Properties dialog box)
* Windows Logo+D (Display the desktop)
* Windows Logo+M (Minimize all of the windows)
* Windows Logo+SHIFT+M (Restore the minimized windows)
* Windows Logo+E (Open My Computer)
* Windows Logo+F (Search for a file or a folder)
* CTRL+Windows Logo+F (Search for computers)
* Windows Logo+F1 (Display Windows Help)
* Windows Logo+ L (Lock the keyboard)
* Windows Logo+R (Open the Run dialog box)
* Windows Logo+U (Open Utility Manager)

Accessibility keyboard shortcuts

* Right SHIFT for eight seconds (Switch FilterKeys either on or off)
* Left ALT+left SHIFT+PRINT SCREEN (Switch High Contrast either on or off)
* Left ALT+left SHIFT+NUM LOCK (Switch the MouseKeys either on or off)
* SHIFT five times (Switch the StickyKeys either on or off)
* NUM LOCK for five seconds (Switch the ToggleKeys either on or off)
* Windows Logo +U (Open Utility Manager)

Windows Explorer keyboard shortcuts

* END (Display the bottom of the active window)
* HOME (Display the top of the active window)
* NUM LOCK+Asterisk sign (*) (Display all of the subfolders that are under the selected folder)
* NUM LOCK+Plus sign (+) (Display the contents of the selected folder)
* NUM LOCK+Minus sign (-) (Collapse the selected folder)
* LEFT ARROW (Collapse the current selection if it is expanded, or select the parent folder)
* RIGHT ARROW (Display the current selection if it is collapsed, or select the first subfolder)

Shortcut keys for Character Map

After you double-click a character on the grid of characters, you can move through the grid by using the keyboard shortcuts:

* RIGHT ARROW (Move to the right or to the beginning of the next line)
* LEFT ARROW (Move to the left or to the end of the previous line)
* UP ARROW (Move up one row)
* DOWN ARROW (Move down one row)
* PAGE UP (Move up one screen at a time)
* PAGE DOWN (Move down one screen at a time)
* HOME (Move to the beginning of the line)
* END (Move to the end of the line)
* CTRL+HOME (Move to the first character)
* CTRL+END (Move to the last character)
* SPACEBAR (Switch between Enlarged and Normal mode when a character is selected)

Microsoft Management Console (MMC) main window keyboard shortcuts

* CTRL+O (Open a saved console)
* CTRL+N (Open a new console)
* CTRL+S (Save the open console)
* CTRL+M (Add or remove a console item)
* CTRL+W (Open a new window)
* F5 key (Update the content of all console windows)
* ALT+SPACEBAR (Display the MMC window menu)
* ALT+F4 (Close the console)
* ALT+A (Display the Action menu)
* ALT+V (Display the View menu)
* ALT+F (Display the File menu)
* ALT+O (Display the Favorites menu)

MMC console window keyboard shortcuts

* CTRL+P (Print the current page or active pane)
* ALT+Minus sign (-) (Display the window menu for the active console window)
* SHIFT+F10 (Display the Action shortcut menu for the selected item)
* F1 key (Open the Help topic, if any, for the selected item)
* F5 key (Update the content of all console windows)
* CTRL+F10 (Maximize the active console window)
* CTRL+F5 (Restore the active console window)
* ALT+ENTER (Display the Properties dialog box, if any, for the selected item)
* F2 key (Rename the selected item)
* CTRL+F4 (Close the active console window. When a console has only one console window, this shortcut closes the console)

Remote desktop connection navigation

* CTRL+ALT+END (Open the Microsoft Windows NT Security dialog box)
* ALT+PAGE UP (Switch between programs from left to right)
* ALT+PAGE DOWN (Switch between programs from right to left)
* ALT+INSERT (Cycle through the programs in most recently used order)
* ALT+HOME (Display the Start menu)
* CTRL+ALT+BREAK (Switch the client computer between a window and a full screen)
* ALT+DELETE (Display the Windows menu)
* CTRL+ALT+Minus sign (-) (Place a snapshot of the entire client window area on the Terminal server clipboard and provide the same functionality as pressing ALT+PRINT SCREEN on a local computer.)
* CTRL+ALT+Plus sign (+) (Place a snapshot of the active window in the client on the Terminal server clipboard and provide the same functionality as pressing PRINT SCREEN on a local computer.)

Microsoft Internet Explorer navigation

* CTRL+B (Open the Organize Favorites dialog box)
* CTRL+E (Open the Search bar)
* CTRL+F (Start the Find utility)
* CTRL+H (Open the History bar)
* CTRL+I (Open the Favorites bar)
* CTRL+L (Open the Open dialog box)
* CTRL+N (Start another instance of the browser with the same Web address)
* CTRL+O (Open the Open dialog box, the same as CTRL+L)
* CTRL+P (Open the Print dialog box)
* CTRL+R (Update the current Web page)
* CTRL+W (Close the current window)

Telecommunication Network

2008-09-10T20:19:00.000-07:00

A communications network is a network of telecommunication links and nodes arranged so that messages can be passed from one part of the network to another on multiple links and through various knots.

Red links telecommunications (including its endpoints or "nodes"), in turn, can be built outside the transmission systems hierarchical.

Examples of communications networks are as follows:

* Computer Network
* Internet-The Internet is a global network of "network of networks". The Internet is connected via an Internet service provider (ISP), then becomes part of a network. This network is connected to a larger corporate network that interconnects with other similar networks throughout Network Access Point (NAP). [1] [2]
* The public switched telephone network
* The global network Telex
* Air, the network ACARS

What Is Topology

2007-06-24T21:08:00.000-07:00

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

Line Configuration

2007-06-24T21:07:00.000-07:00

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

De Facto Standard

2007-06-24T20:58:00.001-07:00

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

What is Standard?

2007-06-24T20:57:00.002-07:00

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.

What is Protocol

2007-06-24T20:57:00.001-07:00

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

2007-06-24T20:56:00.002-07:00

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 and standard

2007-06-24T20:56:00.001-07:00

Applications

2007-06-24T20:55:00.002-07:00

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

Security

2007-06-24T20:55:00.001-07:00

Protecting data from
Unauthorised Access
-user id & password
-encryption technique
Viruses

Network Criteria

2007-06-24T20:54:00.002-07:00

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

NETWORK

2007-06-24T20:54:00.001-07:00

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

Basic Elements or Component

2007-06-24T20:53:00.000-07:00

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

Basic Elements /Components of Data Communication

2007-06-24T20:52:00.002-07:00

1.Sender
2.Receiver
3.Medium
4.Message
5.Protocol

FUNDAMENTALS OF DATA COMMUNICATION

2007-06-24T20:52:00.001-07:00

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.

What Is Data

2007-06-24T20:47:00.001-07:00

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 )