Dialup services offer cost-effective methods for connectivity across WANs. Two popular dialup implementations are dial-on-demand routing (DDR) and dial backup.
DDR is a technique whereby a router can dynamically initiate a call on a switched circuit when it needs to send data. In a DDR setup, the router is configured to initiate the call when certain criteria are met, such as a particular type of network traffic needing to be transmitted. When the connection is made, traffic passes over the line. The router configuration specifies an idle timer that tells the router to drop the connection when the circuit has remained idle for a certain period.
Dial backup is another way of configuring DDR. However, in dial backup, the switched circuit is used to provide backup service for another type of circuit, such as point-to-point or packet switching. The router is configured so that when a failure is detected on the primary circuit, the dial backup line is initiated. The dial backup line then supports the WAN connection until the primary circuit is restored. When this occurs, the dial backup connection is terminated.
Tuesday, December 2, 2008
WAN Virtual Circuits
A virtual circuit is a logical circuit created within a shared network between two network devices. Two types of virtual circuits exist: switched virtual circuits (SVCs) and permanent virtual circuits (PVCs).
SVCs are virtual circuits that are dynamically established on demand and terminated when transmission is complete. Communication over an SVC consists of three phases: circuit establishment, data transfer, and circuit termination. The establishment phase involves creating the virtual circuit between the source and destination devices. Data transfer involves transmitting data between the devices over the virtual circuit, and the circuit termination phase involves tearing down the virtual circuit between the source and destination devices. SVCs are used in situations in which data transmission between devices is sporadic, largely because SVCs increase bandwidth used due to the circuit establishment and termination phases, but they decrease the cost associated with constant virtual circuit availability.
PVC is a permanently established virtual circuit that consists of one mode: data transfer. PVCs are used in situations in which data transfer between devices is constant. PVCs decrease the bandwidth use associated with the establishment and termination of virtual circuits, but they increase costs due to constant virtual circuit availability. PVCs are generally configured by the service provider when an order is placed for service.
SVCs are virtual circuits that are dynamically established on demand and terminated when transmission is complete. Communication over an SVC consists of three phases: circuit establishment, data transfer, and circuit termination. The establishment phase involves creating the virtual circuit between the source and destination devices. Data transfer involves transmitting data between the devices over the virtual circuit, and the circuit termination phase involves tearing down the virtual circuit between the source and destination devices. SVCs are used in situations in which data transmission between devices is sporadic, largely because SVCs increase bandwidth used due to the circuit establishment and termination phases, but they decrease the cost associated with constant virtual circuit availability.
PVC is a permanently established virtual circuit that consists of one mode: data transfer. PVCs are used in situations in which data transfer between devices is constant. PVCs decrease the bandwidth use associated with the establishment and termination of virtual circuits, but they increase costs due to constant virtual circuit availability. PVCs are generally configured by the service provider when an order is placed for service.
Packet Switching
Packet switching is a WAN technology in which users share common carrier resources. Because this allows the carrier to make more efficient use of its infrastructure, the cost to the customer is generally much better than with point-to-point lines. In a packet switching setup, networks have connections into the carrier's network, and many customers share the carrier's network. The carrier can then create virtual circuits between customers' sites by which packets of data are delivered from one to the other through the network. The section of the carrier's network that is shared is often referred to as a cloud.
Some examples of packet-switching networks include Asynchronous Transfer Mode (ATM), Frame Relay, Switched Multimegabit Data Services (SMDS), and X.25. Figure
3-4 shows an example packet-switched circuit.
The virtual connections between customer sites are often referred to as a virtual circuit.
Figure 3-4 Packet Switching Transfers Packets Across a Carrier Network
Some examples of packet-switching networks include Asynchronous Transfer Mode (ATM), Frame Relay, Switched Multimegabit Data Services (SMDS), and X.25. Figure
3-4 shows an example packet-switched circuit.
The virtual connections between customer sites are often referred to as a virtual circuit.
Figure 3-4 Packet Switching Transfers Packets Across a Carrier Network
Circuit Switching
Switched circuits allow data connections that can be initiated when needed and terminated when communication is complete. This works much like a normal telephone line works for voice communication. Integrated Services Digital Network (ISDN) is a good example of circuit switching. When a router has data for a remote site, the switched circuit is initiated with the circuit number of the remote network. In the case of ISDN circuits, the device actually places a call to the telephone number of the remote ISDN circuit. When the
two networks are connected and authenticated, they can transfer data. When the data transmission is complete, the call can be terminated. Figure 3-3 illustrates an example of this type of circuit.
Figure 3-3 A Circuit-Switched WAN Undergoes a Process Similar to That Used for a Telephone
two networks are connected and authenticated, they can transfer data. When the data transmission is complete, the call can be terminated. Figure 3-3 illustrates an example of this type of circuit.
Figure 3-3 A Circuit-Switched WAN Undergoes a Process Similar to That Used for a Telephone
Point-to-Point Links
A point-to-point link provides a single, pre-established WAN communications path from the customer premises through a carrier network, such as a telephone company, to a remote network. Point-to-point lines are usually leased from a carrier and thus are often called leased lines. For a point-to-point line, the carrier allocates pairs of wire and facility hardware to your line only. These circuits are generally priced based on bandwidth required and distance between the two connected points. Point-to-point links are generally more expensive than shared services such as Frame Relay. Figure 3-2 illustrates a typical point-to-point link through a WAN.
Figure 3-2 A Typical Point-to-Point Link Operates Through a WAN to a Remote Network
Figure 3-2 A Typical Point-to-Point Link Operates Through a WAN to a Remote Network
What Is a WAN?
A WAN is a data communications network that covers a relatively broad geographic area and that often uses transmission facilities provided by common carriers, such as telephone companies. WAN technologies generally function at the lower three layers of the OSI reference model: the physical layer, the data link layer, and the network layer. Figure 3-1 illustrates the relationship between the common WAN technologies and the OSI model.
Figure 3-1 WAN Technologies Operate at the Lowest Levels of the OSI Model
Tuesday, October 28, 2008
Why We Have Computers
Because computers can display and deal with text, they offer “communication with human beings—communication that far surpasses the numeric display of the common desktop calculator. This communication is achieved through input/output, or I/O. I/O provides the basis for all the work the computer does.
Computers work by dealing with data. You put data into the computer, and it spits something useful back out, for example:
Word Processing: You input text and manipulate it by using word processing software. The computerr can save the text on disk or print the text to create a document.
Databases: You input the raw data or design a database into which others input data. The computer manipulates the data and either displays or prints the results.
Spreadsheets: You enter the calculations, the values, and the way the values relate. The computer makes the calculations and evaluations, displaying or printing the results for you.
Presentations
How Windows XP Works
You can open given computer application programs with Windows by simply finding the program you want and clicking it in the Programs menu of your ttaskbar, or by double-clicking a shortcut for the program on your desktop. Windows acts as an operating system or what many call system software. It can only allow you to run other programs. Within Windows, programs come attached as a package. For example, you have the Windows Explorer, which allows you to delete, copy, move, or rename files. Windows is set up in what is called the GUI environment, which means the Graphical User Interface environment, making it an interfacce that is much easier to use that the old DOS systems of yesteryear.
The Hardware-to-Software Interface
Windows XP interfaces the computer’s hardware with all the software you use. It’s the go-between, the manager, the traffic cop. To do the job, Windows “talks” with the computer’s hardware on the most basic, simple level. Then it provides easy methods of access to other software applications that want to use the computer, especially the disk drives.
Other software can use the computer’s hardware directly as well; Windows has no monopoly. Bust most of the time other programs use Windows to put files on disk, read files, and deal with the disk drives in general.
Computers work by dealing with data. You put data into the computer, and it spits something useful back out, for example:
Word Processing: You input text and manipulate it by using word processing software. The computerr can save the text on disk or print the text to create a document.
Databases: You input the raw data or design a database into which others input data. The computer manipulates the data and either displays or prints the results.
Spreadsheets: You enter the calculations, the values, and the way the values relate. The computer makes the calculations and evaluations, displaying or printing the results for you.
Presentations
How Windows XP Works
You can open given computer application programs with Windows by simply finding the program you want and clicking it in the Programs menu of your ttaskbar, or by double-clicking a shortcut for the program on your desktop. Windows acts as an operating system or what many call system software. It can only allow you to run other programs. Within Windows, programs come attached as a package. For example, you have the Windows Explorer, which allows you to delete, copy, move, or rename files. Windows is set up in what is called the GUI environment, which means the Graphical User Interface environment, making it an interfacce that is much easier to use that the old DOS systems of yesteryear.
The Hardware-to-Software Interface
Windows XP interfaces the computer’s hardware with all the software you use. It’s the go-between, the manager, the traffic cop. To do the job, Windows “talks” with the computer’s hardware on the most basic, simple level. Then it provides easy methods of access to other software applications that want to use the computer, especially the disk drives.
Other software can use the computer’s hardware directly as well; Windows has no monopoly. Bust most of the time other programs use Windows to put files on disk, read files, and deal with the disk drives in general.
Computers in Surgery
Implementing Computers into surgery is a new and exciting area of study. It has only been in the past 10 years that computers have started to be incorporated with surgery.
In 1989, abstracts of the surgical literature were being distributed on 5.25-inch floppy disks. These abstracts were then used in medical operations and evaluations. Doctors could travel though menus in the abstracts and eventually targeting a solution, procedure, or cause of illnesses. This made the time it takes to flip through pages and pages of medical journals and textbooks less expansive and cumbersome.
Doctors have now gotten to the point where laptops are brought into surgery and are used to aid doctors and nurses. Instead of saying “Nurse, scalpel,” surgeons ask their nurses to find information on the laptops.
Besides holding information, Computers can also be used to manipulate tools and other things in the operating room. Mechanical arms are often used to perform procedures. Sometimes a computer is used to navigate cameras inside of the human body in order to locate tumors and blockages.
Computers are also used to analyze images taken before surgery. Dr. Ninian Peckitt uses software to analyze a CAT scan images in order to understand his patient’s skull. The program in the computer actually directions for making full size replicas of patients heads.
In conclusion, there is a huge advancement being made as far as computer aided surgeries go. From holding information, analyzing problems, delivering solutions, to performing operations, computers are the next step in medical tools.
In 1989, abstracts of the surgical literature were being distributed on 5.25-inch floppy disks. These abstracts were then used in medical operations and evaluations. Doctors could travel though menus in the abstracts and eventually targeting a solution, procedure, or cause of illnesses. This made the time it takes to flip through pages and pages of medical journals and textbooks less expansive and cumbersome.
Doctors have now gotten to the point where laptops are brought into surgery and are used to aid doctors and nurses. Instead of saying “Nurse, scalpel,” surgeons ask their nurses to find information on the laptops.
Besides holding information, Computers can also be used to manipulate tools and other things in the operating room. Mechanical arms are often used to perform procedures. Sometimes a computer is used to navigate cameras inside of the human body in order to locate tumors and blockages.
Computers are also used to analyze images taken before surgery. Dr. Ninian Peckitt uses software to analyze a CAT scan images in order to understand his patient’s skull. The program in the computer actually directions for making full size replicas of patients heads.
In conclusion, there is a huge advancement being made as far as computer aided surgeries go. From holding information, analyzing problems, delivering solutions, to performing operations, computers are the next step in medical tools.
How to Buy a PC ??????
Specific Purpose: To inform my audience what to look for when buying a personal computer.
Central Idea: Computers are sold in a wide variety of configurations and choosing one to fit each individuals needs can be difficult.
Introduction
I. What specific purposes will the individual use the computer for?
A. Computers are not just for business.
B. Seventy percent of U.S. households have computers.
C. Consumers use computers for wide range of uses.
D. Difficulty in choosing a computer to fit both the needs and the budget.
II. Components of the computer to consider when making a purchase.
A. Processors – CPU’s.
B. Memory.
C. Hard Drives.
D. Ports – USB
E. Multimedia. CD, DVD, CD-Rewritable drives, graphics and sound cards.
F. Monitors.
III. The three basic categories that computer users fit into:
Family, Gaming and Multimedia, and Students.
A. Family – basic uses and configurations and prices.
B. Gaming and Multimedia – uses, configurations and prices.
C. Family – uses, configurations and prices.
Conclusion
I. A personal computer purchase should not be an impulse buy.
Do your research. Shop around and compare. With careful
planning and patience you can find the computer to fit your
needs and your budget.
Central Idea: Computers are sold in a wide variety of configurations and choosing one to fit each individuals needs can be difficult.
Introduction
I. What specific purposes will the individual use the computer for?
A. Computers are not just for business.
B. Seventy percent of U.S. households have computers.
C. Consumers use computers for wide range of uses.
D. Difficulty in choosing a computer to fit both the needs and the budget.
II. Components of the computer to consider when making a purchase.
A. Processors – CPU’s.
B. Memory.
C. Hard Drives.
D. Ports – USB
E. Multimedia. CD, DVD, CD-Rewritable drives, graphics and sound cards.
F. Monitors.
III. The three basic categories that computer users fit into:
Family, Gaming and Multimedia, and Students.
A. Family – basic uses and configurations and prices.
B. Gaming and Multimedia – uses, configurations and prices.
C. Family – uses, configurations and prices.
Conclusion
I. A personal computer purchase should not be an impulse buy.
Do your research. Shop around and compare. With careful
planning and patience you can find the computer to fit your
needs and your budget.
COMPUTERS IN EDUCATION
Computers are a new and exciting part of education and learning. They have changed the how student learn, study, and do assignments. Furthermore they have changed the way teachers teach. Every day in computers innovations are made that will improve how computers can be used by educators and students alike.
The most basic way that computers help students is through word processing. Through word processing programs like Claris Works and Microsoft Word students can access programs to edit, correct spelling errors, and much more. Programs can also be bought that will change writing into the MLA format. It also gives students the ability to be creative and add pictures, highlight, underline, and use different fonts.
In some classrooms the teachers use computers to compound what they teach. Computers can be used as projectors, to run programs, or simply to print out information quickly. Use of the internet is also now part of the modern classroom.
There are many tutorial programs available. They are excellent in helping students hone their skills at home. These programs are for the most part affordable and have a wide range of topics. Many young children start using these even before entering school so that they are more prepared when they enter.
Internet access is arguably the best form of computer innovations. Students and teachers alike can use the internet to do research. Researching on the internet is easy and enables one to access many things that they could not with conventional means. Furthermore teachers and students can use it to communicate or to send papers.
As you can see computers are an excellent tool to help in education and learning. There are no boundaries to what computers can do.
The most basic way that computers help students is through word processing. Through word processing programs like Claris Works and Microsoft Word students can access programs to edit, correct spelling errors, and much more. Programs can also be bought that will change writing into the MLA format. It also gives students the ability to be creative and add pictures, highlight, underline, and use different fonts.
In some classrooms the teachers use computers to compound what they teach. Computers can be used as projectors, to run programs, or simply to print out information quickly. Use of the internet is also now part of the modern classroom.
There are many tutorial programs available. They are excellent in helping students hone their skills at home. These programs are for the most part affordable and have a wide range of topics. Many young children start using these even before entering school so that they are more prepared when they enter.
Internet access is arguably the best form of computer innovations. Students and teachers alike can use the internet to do research. Researching on the internet is easy and enables one to access many things that they could not with conventional means. Furthermore teachers and students can use it to communicate or to send papers.
As you can see computers are an excellent tool to help in education and learning. There are no boundaries to what computers can do.
Mainframes and Supercomputers
The oldest category of computers is the mainframe. Mainframe computers are capable of great processing speeds and data storage. They are generally stored in specially wired, highly air conditioned rooms. Because they produce large amounts of heat they produce they are water or air-cooled. Mainframes are made of thousands of light bulb like fixtures called vacuum tubes. They are typically the size of a jeep and range in price from $50,000 to $5 million. These machines are primarily used by large companies such as banks, insurance companies, and airlines, that handle millions of transactions. Mainframes were first produced in the 1940's. Some companies are still using the first mainframes produced such as the Univac. The world has invested one trillion dollars in mainframe computers, sixty percent of which were made and sold by IBM. With the invention of the microprocessor and printed circuit boards mainframes are often being replace by smaller networked computers. As time progresses mainframes will be kept for some purposes, networks of smaller computers will grow, and the mainframe will be reinvented.(Hutchinson) The ENIAC was the first mainframe computer produced. It used 18,000 vacuum tubes, and occupied 1,800 square foot of floor space. It used punch cards for input and output.
Supercomputers are the fastest computers every made. They generally range in price from $225,000 to $30 million. They are high capacity machines that require specially air conditioned rooms. Supercomputers are for people who need to model complex, lifelike situations. Supercomputers are used to simulate car crashed and for weather forecasting. The most powerful supercomputer, Janus, built by Intel, enables scientists to simulate the explosion of a nuclear bomb. In 1995 the National Science Foundation and MCI Communications established a 14,000 mile network called the Very-High-Performance Backbone Network Service(VBNS). The VBNS links the five highest concentration of supercomputer, each locations having up to six supercomputers, into "the new internet." A scientist sitting at any machine could have access to any other machine on the network. Presently this network is only used by a very elite group of scientist for extremely complex projects.
Supercomputers are the fastest computers every made. They generally range in price from $225,000 to $30 million. They are high capacity machines that require specially air conditioned rooms. Supercomputers are for people who need to model complex, lifelike situations. Supercomputers are used to simulate car crashed and for weather forecasting. The most powerful supercomputer, Janus, built by Intel, enables scientists to simulate the explosion of a nuclear bomb. In 1995 the National Science Foundation and MCI Communications established a 14,000 mile network called the Very-High-Performance Backbone Network Service(VBNS). The VBNS links the five highest concentration of supercomputer, each locations having up to six supercomputers, into "the new internet." A scientist sitting at any machine could have access to any other machine on the network. Presently this network is only used by a very elite group of scientist for extremely complex projects.
Desktop versus Laptop Computers
Desktop versus Laptop Computers
Computers are becoming the latest trend on the market. With laptops and desktops being sold at low prices, there has been a major debate over which is better. Desktops for instance were used primarily in businesses. As time passed computers were being introduced into homes and schools. With computer prices tumbling down, laptops are becoming the hottest item on the market.
There are many differences in desktops and laptops. One of the major differences is there size. A laptop for instance was made to be portable while a desktop is used to be stationary. A desktop, which is larger than a laptop, has much more room for expandability. Which in turns makes a desktop less obsolete in the future. With the central processing chip being much smaller in size in a laptop, the speed compared to a desktop is a little slower. With all the inner parts being much smaller in a laptop the pricing on the hard ware is much more expensive. With laptop prices falling they are becoming more available to the public. Laptops are being considered the number one choice for business use. With its versatility, power and great pricing it is no wonder that laptop sales are on the rise. To lure consumers to laptops computer companies have developed a docking station for laptops. A docking station is a device that lets consumers plug their laptop into a docking station that resembles a desktop. The reason for this is to reduce the number of peripherals on laptop. Desktop computers on the other hand have the advantage of taking more additional peripherals than laptops. Desktop computers, which can handle much more graphics than laptops, are used for primarily business use. The reason that laptops cannot handle as much graphics power than a desktop is because of its resolution and power.
There are many differences between laptop computers and desktop computers. Both designs have their advantages and disadvantages, but it is important for consumers to know which is right for them. If you do a lot of traveling and need to keep in touch with your computer a laptop is a great resource. But if you do most of your work in a stationary environment a desktop computer would be a better choice.
Computers are becoming the latest trend on the market. With laptops and desktops being sold at low prices, there has been a major debate over which is better. Desktops for instance were used primarily in businesses. As time passed computers were being introduced into homes and schools. With computer prices tumbling down, laptops are becoming the hottest item on the market.
There are many differences in desktops and laptops. One of the major differences is there size. A laptop for instance was made to be portable while a desktop is used to be stationary. A desktop, which is larger than a laptop, has much more room for expandability. Which in turns makes a desktop less obsolete in the future. With the central processing chip being much smaller in size in a laptop, the speed compared to a desktop is a little slower. With all the inner parts being much smaller in a laptop the pricing on the hard ware is much more expensive. With laptop prices falling they are becoming more available to the public. Laptops are being considered the number one choice for business use. With its versatility, power and great pricing it is no wonder that laptop sales are on the rise. To lure consumers to laptops computer companies have developed a docking station for laptops. A docking station is a device that lets consumers plug their laptop into a docking station that resembles a desktop. The reason for this is to reduce the number of peripherals on laptop. Desktop computers on the other hand have the advantage of taking more additional peripherals than laptops. Desktop computers, which can handle much more graphics than laptops, are used for primarily business use. The reason that laptops cannot handle as much graphics power than a desktop is because of its resolution and power.
There are many differences between laptop computers and desktop computers. Both designs have their advantages and disadvantages, but it is important for consumers to know which is right for them. If you do a lot of traveling and need to keep in touch with your computer a laptop is a great resource. But if you do most of your work in a stationary environment a desktop computer would be a better choice.
uses
Computers are helpful because they offer a wide range of functions and services that are not available anywhere else. There are four main uses: word processing, internet/communications, digital video/audio composition, and desktop publishing. Although one can create a typed paper with a typewriter, the computer has more features
to do it with. Internet and communications, digital video and audio composition, and desktop publishing are all features that are only offered on computers. With these tools human society has progressed exponentially.
The word processing capabilities of computers are amazing. They can automatically correct your spelling and grammar mistakes. The cutting and pasting features are incredibly simple and very useful for revision. Plus it is easier to read a word-processed document than one written by hand. Having a digital backup is an added benefit. All of these things help writers get the job done. If you want to add pictures to your writing, numerous software titles are available for desktop publishing. With desktop publishing, you can create page layouts for entire books on your home computer. For example, high school yearbook classes now use desktop publishing software for the creation and design
of their yearbooks. Most of this cannot be done by hand, and if so, then it is painstakingly laborious.
The Internet is one of the greatest inventions of humanity. It is a massive network of computers, each with the ability to access any of the others. Ungodly amounts of information can be found on the Internet. It is the ultimate form of media, a combination of newspaper, radio, and as the average bandwidth is increasing, television. Using
the Internet, any two people anywhere can communicate for free, whether it is with text or voice. Video conferencing tools are becoming readily available to the public. New uses are being found for the Internet every day.
Audio/video editing and composition have been made much easier by computers. Cutting and pasting is no longer comprised of using scissors and tape on large reels of film. It no longer costs thousands of dollars of equipment to make a film or to compose music. Now emerging musicians have the ability to compose their own songs and publish them without having to obtain a record contract. Amateur filmmakers can produce work from their own homes. Graphics engineers can use computers to create three-dimensional models, or even to generate short or full-length films. Anybody who owns a computer can now enter the field of media production.
Computers have so many uses that cannot be found anywhere else. Word processors are the perfect writing device because you can compose quickly and make changes easily. The Internet provides a fast, free, and unique way to get information or to communicate with others. Computers supply an affordable solution to nonprofessional audio and video composition. These reasons are why computers are so helpful in modern society. With the aid of computers, humankind is entering a new era of enlightenment.
to do it with. Internet and communications, digital video and audio composition, and desktop publishing are all features that are only offered on computers. With these tools human society has progressed exponentially.
The word processing capabilities of computers are amazing. They can automatically correct your spelling and grammar mistakes. The cutting and pasting features are incredibly simple and very useful for revision. Plus it is easier to read a word-processed document than one written by hand. Having a digital backup is an added benefit. All of these things help writers get the job done. If you want to add pictures to your writing, numerous software titles are available for desktop publishing. With desktop publishing, you can create page layouts for entire books on your home computer. For example, high school yearbook classes now use desktop publishing software for the creation and design
of their yearbooks. Most of this cannot be done by hand, and if so, then it is painstakingly laborious.
The Internet is one of the greatest inventions of humanity. It is a massive network of computers, each with the ability to access any of the others. Ungodly amounts of information can be found on the Internet. It is the ultimate form of media, a combination of newspaper, radio, and as the average bandwidth is increasing, television. Using
the Internet, any two people anywhere can communicate for free, whether it is with text or voice. Video conferencing tools are becoming readily available to the public. New uses are being found for the Internet every day.
Audio/video editing and composition have been made much easier by computers. Cutting and pasting is no longer comprised of using scissors and tape on large reels of film. It no longer costs thousands of dollars of equipment to make a film or to compose music. Now emerging musicians have the ability to compose their own songs and publish them without having to obtain a record contract. Amateur filmmakers can produce work from their own homes. Graphics engineers can use computers to create three-dimensional models, or even to generate short or full-length films. Anybody who owns a computer can now enter the field of media production.
Computers have so many uses that cannot be found anywhere else. Word processors are the perfect writing device because you can compose quickly and make changes easily. The Internet provides a fast, free, and unique way to get information or to communicate with others. Computers supply an affordable solution to nonprofessional audio and video composition. These reasons are why computers are so helpful in modern society. With the aid of computers, humankind is entering a new era of enlightenment.
Friday, August 22, 2008
laptop
A laptop computer is a convenient portable computer that has gained wide popularity with people who travel a lot, study in coffee shops, and particularly for those who enjoy the space saving design. Laptops have come a long way with optional features such as integrated web camera for video chatting,. Laptops with wi-fi technology for connecting to a wireless network or an internet hot spot and mobile broadband to connect anywhere are very convenient. Laptops with a bluetooth reader, finger print scanner, or a space saving slot loaded disc drive make technology fun.
When purchasing laptops, think about the best size and weight for your portability needs. Laptops in colors or designs that fits your personality are available. If you use your laptop for multimedia, consider purchasing a larger laptop hard drive and discreet laptop video card.
When purchasing laptops, think about the best size and weight for your portability needs. Laptops in colors or designs that fits your personality are available. If you use your laptop for multimedia, consider purchasing a larger laptop hard drive and discreet laptop video card.
acer
Acer Veriton S461 series of business desktop PCs announced
Tuesday, July 22nd, 2008
Acer announces its new Veriton S461 series of business desktop PCs featuring more security and manageability. The S461 series claims to provide all the essentials required by the demanding business environments.
The Veriton S461 features streamlined form factor design, an Intel Core 2 Duo processor, high-capacity hard disk drive and dual-channel DDR2 memory, providing the […]
Tuesday, July 22nd, 2008
Acer announces its new Veriton S461 series of business desktop PCs featuring more security and manageability. The S461 series claims to provide all the essentials required by the demanding business environments.
The Veriton S461 features streamlined form factor design, an Intel Core 2 Duo processor, high-capacity hard disk drive and dual-channel DDR2 memory, providing the […]
ipower
Packard Bell ipower X2.0 gaming desktop unveiled
Wednesday, July 9th, 2008
Packard Bell unveils its new ipower X2.0 gaming machine at the Electronic Sports World Cup in Paris. Targeting gamers, ipower X2.0 features Intel Quad Core Extreme processors, high-end GPUs (Nvidia GeForce 9800X3 or ATI Tadeon HD4870), storage capacity from 500 GB to 3 TB, E-SATA expansion, a Blu-ray disc drive, a 21-in-1 media card […]
Wednesday, July 9th, 2008
Packard Bell unveils its new ipower X2.0 gaming machine at the Electronic Sports World Cup in Paris. Targeting gamers, ipower X2.0 features Intel Quad Core Extreme processors, high-end GPUs (Nvidia GeForce 9800X3 or ATI Tadeon HD4870), storage capacity from 500 GB to 3 TB, E-SATA expansion, a Blu-ray disc drive, a 21-in-1 media card […]
Friday, April 4, 2008
Find the primary domain controller
Find the primary domain controller
With native Windows 2000 commands:
NETDOM QUERY /D:MyDomain PDCor, to find the FSMO with (native) Windows Server 2003 commands (Active Directory only):
NETDOM QUERY /D:mydomain.com FSMONETDOM is part of the support tools found in the \SUPPORT directory of the Windows 2000 installation CDROM.
List all member servers
List all member servers
With native Windows 2000 commands:
NETDOM QUERY /D:MyDomain SERVERNETDOM is part of the support tools found in the \SUPPORT directory of the Windows 2000 installation CDROM.
Delete a computer account
Delete a computer account
With native Windows 2000 commands:
NETDOM /DOMAIN:MyDomain MEMBER \\computer2Bdeleted /DELETENETDOM is part of the support tools found in the \SUPPORT directory of the Windows 2000 installation CDROM.
Is someone's account locked?
How do I reset someone's password?
How do I reset someone's password?
With the native NET command:
NET USER loginname newpassword /DOMAIN
With (native) Windows Server 2003 commands:
DSQUERY USER -samid loginname | DSMOD USER -pwd newpassword| Note: | To prevent the new password from being displayed on screen replace it with an asterisk (*); you will then be prompted (twice) to type the new password "blindly". |
When did someone last change his password?
What permissions does a user have on this directory?
What permissions does a user have on this directory?
One could use the previous command to check what permissions a user has on a certain directory.
However, sometimes SHOWACLS from the Window Server 2003 Resource Kit Tools is a better alternative:
CD /D d:\directory2check
SHOWACLS /U:domain\userid What groups is this user a member of?
What groups is this user a member of?
In Windows NT 4 and later, users usually are members of global groups. These global groups in turn are members of (domain) local groups. Access permissions are given to (domain) local groups.
To check if a user has access to a resource, we need to check group membership recursively.
With (native) Windows Server 2003 commands:
DSQUERY USER -samid loginname | DSGET USER -memberof -expand
What is the full name for this login name?
What is the full name for this login name?
With the native NET command:
NET USER loginname /DOMAIN | FIND /I " name "
With (native) Windows Server 2003 commands:
DSQUERY USER -samid *loginname* | DSGET USER -samid -display| Note: | The NET command may seem more universal, because it requires neither Active Directory nor Windows Server 2003 commands, but it is language dependent! For non-English Windows you may need to modify FIND's search string. |
What is this collegue's login name?
What is this collegue's login name?
My collegues often forget to mention their logon account name when calling the helpdesk, and the helpdesk doesn't always ask either. I suppose they expect me to know all 1500+ accounts by heart.
With (native) Windows Server 2003 commands only:
DSQUERY USER -name *lastname* | DSGET USER -samid -display| Note: | Windows Server 2003's "DSTools" will work fine in Windows 2000 and XP too, when copied. Keep in mind, however, that some Windows Server 2003 Active Directory functionality is not available in Windows 2000 Active Directories. |
Who is logged on to a computer?
Who is logged on to a computer?
We often need to know who is currently logged on to a remote computer.
With native Windows commands only:
NBTSTAT -a remotecomputer | FIND "<03>" | FIND /I /V "remotecomputer"
The first name in the list usually is the logged on user (try playing with the NET NAME command to learn more about the names displayed by NBTSTAT).
This is the fastest way to find the logged on user name, and the results that you do get are correct, but NBTSTAT won't always return a user name, even when a user is logged on.
Using WMIC (Windows XP Professional and later):
WMIC /Node:remotecomputer ComputerSystem Get UserName
This is arguably the most reliable (native) command to find out who is logged on.
With the help of SysInternals' PSTools:
PSLOGGEDON -L \\remotecomputer using gidei
Using GIDEI: Basic Computer Commands
These are some basic computer emulation commands that use the GIDEI (General Input Device Emulating Interface) protocol commands.
To get the
| Return | |
| Backspace | |
| Tab | |
| Escape/Cancel | |
| Print (IBM) Print (Mac) | |
| Save (IBM) | |
| Left Arrow key | |
| Right Arrow key | |
| Up Arrow key | |
| Down Arrow key | |
| Page Up | |
| Page Down |
Remember that the arrow keys are NOT mouse commands. They do what the arrow keys do on a regular keyboard.
Basic Mouse Commands
| Single Click | |
| Double Click | |
| Right Click |
Move commands move the mouse cursor a specific distance on the screen.
Horizontal plus (+) values move the mouse to the right and minus (-) values move it to the left. Vertical plus (+) values move the mouse downward and minus (-) values move the mouse upward. The mouse moves diagonally when both a horizontal and vertical value are sent. The first value given is the horizontal value, the second is the vertical value.
The numbers in the example below tell the computer how far to move the mouse each time this command is used. Increase this number for larger distances, decrease it for shorter distances. The number may vary from 1 to 500.
| Emulator Command | Mouse Cursor Movement You See on the Screen |
| Moves the mouse cursor 5 pixels to the right. | |
| Moves the mouse cursor 5 pixels to the left | |
| Moves the mouse cursor 5 pixels down | |
| Moves the mouse cursor 5 pixels up | |
| Moves the mouse cursor 10 pixels diagonally downward and right | |
| Moves the mouse cursor 10 pixels diagonally downward and left | |
| Moves the mouse cursor 10 pixels diagonally upward and left | |
| Moves the mouse cursor 10 pixels diagonally upward and right | |
| Resets the mouse and sends it to the upper left corner of the screen | |
| Moves the mouse to a specific location on the screen. |
commands
An A-Z Index of the Windows XP command line
ADDUSERS Add or list users to/from a CSV file
ARP Address Resolution Protocol
ASSOC Change file extension associations
ASSOCIAT One step file association
AT Schedule a command to run at a later time
ATTRIB Change file attributes
BOOTCFG Edit Windows boot settings
BROWSTAT Get domain, browser and PDC info
CACLS Change file permissions
CALL Call one batch program from another
CD Change Directory - move to a specific Folder
CHANGE Change Terminal Server Session properties
CHKDSK Check Disk - check and repair disk problems
CHKNTFS Check the NTFS file system
CHOICE Accept keyboard input to a batch file
CIPHER Encrypt or Decrypt files/folders
CleanMgr Automated cleanup of Temp files, recycle bin
CLEARMEM Clear memory leaks
CLIP Copy STDIN to the Windows clipboard.
CLS Clear the screen
CLUSTER Windows Clustering
CMD Start a new CMD shell
COLOR Change colors of the CMD window
COMP Compare the contents of two files or sets of files
COMPACT Compress files or folders on an NTFS partition
COMPRESS Compress individual files on an NTFS partition
CON2PRT Connect or disconnect a Printer
CONVERT Convert a FAT drive to NTFS.
COPY Copy one or more files to another location
CSCcmd Client-side caching (Offline Files)
CSVDE Import or Export Active Directory data
DATE Display or set the date
Dcomcnfg DCOM Configuration Utility
DEFRAG Defragment hard drive
DEL Delete one or more files
DELPROF Delete NT user profiles
DELTREE Delete a folder and all subfolders
DevCon Device Manager Command Line Utility
DIR Display a list of files and folders
DIRUSE Display disk usage
DISKCOMP Compare the contents of two floppy disks
DISKCOPY Copy the contents of one floppy disk to another
DNSSTAT DNS Statistics
DOSKEY Edit command line, recall commands, and create macros
DSADD Add user (computer, group..) to active directory
DSQUERY List items in active directory
DSMOD Modify user (computer, group..) in active directory
ECHO Display message on screen
ENDLOCAL End localisation of environment changes in a batch file
ERASE Delete one or more files
EXIT Quit the CMD shell
EXPAND Uncompress files
EXTRACT Uncompress CAB files
FC Compare two files
FDISK Disk Format and partition
FIND Search for a text string in a file
FINDSTR Search for strings in files
FOR /F Loop command: against a set of files
FOR /F Loop command: against the results of another command
FOR Loop command: all options Files, Directory, List
FORFILES Batch process multiple files
FORMAT Format a disk
FREEDISK Check free disk space (in bytes)
FSUTIL File and Volume utilities
FTP File Transfer Protocol
FTYPE Display or modify file types used in file extension associations
GLOBAL Display membership of global groups
GOTO Direct a batch program to jump to a labelled line
HELP Online Help
HFNETCHK Network Security Hotfix Checker
IF Conditionally perform a command
IFMEMBER Is the current user in an NT Workgroup
IPCONFIG Configure IP
KILL Remove a program from memory
LABEL Edit a disk label
LOCAL Display membership of local groups
LOGEVENT Write text to the NT event viewer.
LOGOFF Log a user off
LOGTIME Log the date and time in a file
MAPISEND Send email from the command line
MEM Display memory usage
MD Create new folders
MKLINK Create a symbolic link (linkd)
MODE Configure a system device
MORE Display output, one screen at a time
MOUNTVOL Manage a volume mount point
MOVE Move files from one folder to another
MOVEUSER Move a user from one domain to another
MSG Send a message
MSIEXEC Microsoft Windows Installer
MSINFO Windows NT diagnostics
MSTSC Terminal Server Connection (Remote Desktop Protocol)
MUNGE Find and Replace text within file(s)
MV Copy in-use files
NET Manage network resources
NETDOM Domain Manager
NETSH Configure network protocols
NETSVC Command-line Service Controller
NBTSTAT Display networking statistics (NetBIOS over TCP/IP)
NETSTAT Display networking statistics (TCP/IP)
NOW Display the current Date and Time
NSLOOKUP Name server lookup
NTBACKUP Backup folders to tape
NTRIGHTS Edit user account rights
PATH Display or set a search path for executable files
PATHPING Trace route plus network latency and packet loss
PAUSE Suspend processing of a batch file and display a message
PERMS Show permissions for a user
PERFMON Performance Monitor
PING Test a network connection
POPD Restore the previous value of the current directory saved by PUSHD
PORTQRY Display the status of ports and services
PRINT Print a text file
PRNCNFG Display, configure or rename a printer
PRNMNGR Add, delete, list printers set the default printer
PROMPT Change the command prompt
PsExec Execute process remotely
PsFile Show files opened remotely
PsGetSid Display the SID of a computer or a user
PsInfo List information about a system
PsKill Kill processes by name or process ID
PsList List detailed information about processes
PsLoggedOn Who's logged on (locally or via resource sharing)
PsLogList Event log records
PsPasswd Change account password
PsService View and control services
PsShutdown Shutdown or reboot a computer
PsSuspend Suspend processes
PUSHD Save and then change the current directory
QGREP Search file(s) for lines that match a given pattern.
RASDIAL Manage RAS connections
RASPHONE Manage RAS connections
RECOVER Recover a damaged file from a defective disk.
REG Registry: Read, Set, Export, Delete keys and values
REGEDIT Import or export registry settings
REGSVR32 Register or unregister a DLL
REGINI Change Registry Permissions
REM Record comments (remarks) in a batch file
REN Rename a file or files.
REPLACE Replace or update one file with another
RD Delete folder(s)
RDISK Create a Recovery Disk
RMTSHARE Share a folder or a printer
ROBOCOPY Robust File and Folder Copy
ROUTE Manipulate network routing tables
RUNAS Execute a program under a different user account
RUNDLL32 Run a DLL command (add/remove print connections)
SC Service Control
SCHTASKS Create or Edit Scheduled Tasks
SCLIST Display NT Services
ScriptIt Control GUI applications
SET Display, set, or remove environment variables
SETLOCAL Control the visibility of environment variables
SETX Set environment variables permanently
SHARE List or edit a file share or print share
SHIFT Shift the position of replaceable parameters in a batch file
SHORTCUT Create a windows shortcut (.LNK file)
SHOWGRPS List the NT Workgroups a user has joined
SHOWMBRS List the Users who are members of a Workgroup
SHUTDOWN Shutdown the computer
SLEEP Wait for x seconds
SOON Schedule a command to run in the near future
SORT Sort input
START Start a separate window to run a specified program or command
SU Switch User
SUBINACL Edit file and folder Permissions, Ownership and Domain
SUBST Associate a path with a drive letter
SYSTEMINFO List system configuration
TASKLIST List running applications and services
TIME Display or set the system time
TIMEOUT Delay processing of a batch file
TITLE Set the window title for a CMD.EXE session
TOUCH Change file timestamps
TRACERT Trace route to a remote host
TREE Graphical display of folder structure
TYPE Display the contents of a text file
USRSTAT List domain usernames and last login
VER Display version information
VERIFY Verify that files have been saved
VOL Display a disk label
WHERE Locate and display files in a directory tree
WHOAMI Output the current UserName and domain
WINDIFF Compare the contents of two files or sets of files
WINMSD Windows system diagnostics
WINMSDP Windows system diagnostics II
WMIC WMI Commands
XCACLS Change file permissions
XCOPY Copy files and folders
Subscribe to:
Posts (Atom)