Computer Systems and Networking | Leveraging Modern Technology

How Bluetooth Works

2010-02-23T06:06:00.000-08:00

Bluetooth devices will normally operate at 2.4 GHZ in the license free, globally available ISM radio band. The advantage to this band includes worldwide availability and compatibility. A disadvantage to this however, is that the devices must share this band with other RF emitters. This includes automobile security systems, other wireless devices, and other noise sources, such as microwaves.

To overcome this challenge, Bluetooth employs a fast frequency hopping scheme and therefore uses shorter packets than other standards within the ISM band. This scheme helps to make Bluetooth communication more robust and more secure.

Frequency hopping

Frequency hopping is basically jumping from frequency to frequency within the ISM radio band. After a bluetooth device sends or receives a packet, it and the device (or devices) it's communicating with hop to another frequency before the next packet is sent. This scheme offers three advantages:

1. Allows Bluetooth devices to use the entirety of the available ISM band, while never transmitting from a fixed frequency for more than a short period of time. This helps insure that Bluetooth conforms to the ISM restrictions on the transmission quantity per frequency.

2. Ensures that any interference won't last long. Any packet that doesn't arrive safely to its destination can be resent to the next frequency.

3. Provides a base level of security as it's very hard for an eavesdropping device to predict which frequency the Bluetooth devices will use next.

The connected devices however, must agree upon the frequency they will use next. The specification in Bluetooth ensures this in two ways. First, it defines a master and slave type relationship between bluetooth devices. Next, it specifies an algorithm that uses device specific information when calculating the frequency hop sequences.

A Bluetooth device that operates in master mode can communicate with up to seven devices that are set in slave mode. To each of the slaves, the master Bluetooth device will send its own unique address and the value of its own internal clock. The information sent is then used to calculate the frequency hop sequences.

Because the master device and each of the slave devices use the same algorithm with the same initial input, the connected devices will always arrive together at the next frequency that they have agreed upon.

As a replacement for cable technology, it's no wonder that Bluetooth devices are usually battery powered, such as wireless mice and battery powered cell phones. To conserve the power, most devices operate in low power. This helps to give Bluetooth devices a range of around 5 - 10 meters.

This range is far enough for wireless communication but close enough to avoid drawing too much power from the power source of the device.

What Is An Intranet? Definition and Uses...

2009-11-20T23:20:00.000-08:00

An intranet is basically a private web based network. It uses all of the technology of the internet but is safe and protected behind a firewall that keeps unauthorized personnel out. Companies have been using them for years as a method of streamlining their internal communications.
Because a web browser can run on any type of computer, the need to maintain multiple paper copies of documents that are constantly changing can be eliminated. Documents like training manuals, internal phone books, procedure manuals, benefits information, employee handbooks, requisition forms, etc. can be maintained as electronic documents and updated at almost no cost. The savings in paper and other material costs can be significant, but the most powerful aspect of an intranet is its ability to display information in the same format to every computer being used. That allows all of the different software and databases a company uses to be available to all employees without any special equipment or software being installed on their systems.

This universal availability of information is sparking an era of collaboration unlike anything ever seen before. The departmental barriers that exist in many companies are slowing breaking down because now colleagues can share information readily using the company intranet.

Options for implementing an intranet

There are a variety of options for setting up an intranet. They include building your own intranet technology, purchasing and installing third-party software, or purchasing access through an extranet ASP. Here is a quick summary of the advantages and disadvantages of each approach:

1. Building it yourselfAdvantages:

Complete control of user interface design; ability to customize level of functionality; integration into internal systems, and direct access to user activity.
Disadvantages: High up-front development cost; requires staff expertise in the development of extranets, commitment of internal staff for 6 months to a year for planning, execution, review and implementation; and an ongoing commitment of internal staff for internal and client support, hosting, maintenance and upgrades.

2. Purchasing/installing third-party softwareAdvantages:

Proven track-record of packaged solution; ability to choose functions and tocustomize user interface, more rapid implementation compared to building it yourself.
Disadvantages: High up-front purchase cost; commitment of internal staff for customization and implementation; on-going commitment of internal staff for internal and client support, hosting, maintenance and upgrades; and extensive internal and client training

3. Using a Service Provider (ASP)Advantages:

Proven track-record of the application; low cost of entry and predictable cost over time; virtually immediate implementation; no commitment of internal staff for internal support, hosting, or maintenance; and upgrades at no cost by extranet experts, and savings on internal server use.
Disadvantages: Less freedom in user interface design, and fixed functionality.

In the final analysis…The approach you choose depends on how you work, the technical and financial resources at your disposal, and how rapidly you need to move forward.

Surfing the Web Anonymously

2009-05-12T06:21:00.000-07:00

Whenever you surf the web it is possible to find out information about you even when you do not want to publicize who you are. This is a fact, even if your computer contains no virus or malware software. The information that can be tracked easily include IP address, country, computer system being using, browser, browser history, and other related information. It gets even worse. People can get your computer's name and even find out your name. Also, cookies can track your habits as you move from one computer to another.

How do people get this basic information about you?

When you visit one website to another web site, information about you can be recovered. Basically, information is intercepted and used by others to follow your Internet activities.

How do you stop this from happening?

First of all, it is possible to surf the web anonymously and thereby stop leaving a trail for others to find. Note that this is not fool-proof, but it makes it much harder for people to know who you are. There are some sophisticated products called anonymous proxy servers that help in protecting you. These anonymous proxy servers replace user’s Internet address for its own. This has the effect of hiding your IP address and making it much harder for people to track you.

How do I get an anonymous proxy server?

There are many vendors who sell anonymous proxy servers. There are also free proxy servers available to you. Two such products are ShadowSurf and Guardster. They provide various services for anonymous and secure access to the web, some are paid and some are free as well. They provide anonymous surfing at their site for free. Go to it and you will find a box to enter a URL that you want no one to track. There are many others, but here are two that are frequently used.

Another wonderful product, given the recent news about the Google search engine filtering its findings for the Chinese government, is Anonymizer. This company pressed that it is developing a new anti-censorship solution that will enable Chinese citizens to safely access the entire Internet filter-free

Does an anonymous proxy server make you 100% safe?

No. Still, you are much better off if you use such technology.

What other things should I be concerned about when trying to keep my private information private?

Three other items come to mind when trying to keep your information private. First, you can use an encrypted connection to hide your surfing. Secondly, delete cookies after each session. Third, you can configure your browser to remove JavaScript, Java, and active content. This actually leads to limitations, so you need to think about the cost/benefit of this course of action.

The Future World of Computers and Networking

2009-04-23T04:52:00.000-07:00

Can you imagine the future world of Modern Technology? It’s totally amazing that the Web World is 20 years old now. Children ask us what we all did before the Internet by which they mean the browser based world of Google, E-bay, You Tube and Club Penguin.

How did we communicate when there were no computers and modern means of communication? Well, I remember that we used to write lots of letters to friends and relatives to stay in touch and were thrilled when someone wrote back. Also it was too expensive to make long distance phone calls in those days. I also spent a lot of time in the library and in book stores looking for books, magazines, research papers etc. for want of information.
Now, after Personal Computer revolution and World Wide Web transformation, it definitely feels like the golden days that my grandparents lived in. Now-a-days we blog, post, comment, Google, Instant Message, Twitter, Web conference, share screens, capture group chats. We can turnaround our ideas in minutes, feel Real presence, Global distribution, Shared authoring in real time.

What about the Future?

I do not think we have to look very far to find what lies ahead in the next five years because it’s already here in primitive form. It’s user friendly IM, VoIP, desktop and Tele presence video conferencing, real-time co-authoring, Web-centric productivity and collaboration tools, much better search through company information and data, virtual world meeting spaces, unified conferencing. Remote team members as connected to you as those a single floor away, meeting centric collaboration platforms, content derived expertise identification, tag clouds at the heart of semantically drive search, analytical graphs at the heart of expertise location, and of course all services available from a mobile Internet device. More and more online shops are defining new ways of shopping.

Windows Backup Software- Protect Your Computer From Data Loss

2009-04-02T10:12:00.000-07:00

Using Windows backup software for protecting yourself from data loss can be confusing at the first moment. How often should a backup be created? Should one create a full Windows backup or just some files? How would one get his data back if computer crashes? Is it possible to create a hard drive backup? Today I will provide you a complete Windows backup solution for keeping your files safe. The common dangers that make it necessary to backup a computer are given below:
1. Hard drive crash: Sometimes hard drives die. This can cause data loses, non-booting operating system and many other issues. In case of hard drive crash one would need to buy a new one and somehow migrate with all his data from an old disk to this new one – that is the job for Windows backup software.
2. System crash: This happens more often than most users think. They have their machines working now and it seems that it would be like this always. But sometimes you need just to reboot the machine to get BSOD (Blue Screen Of Death) instead of Windows logo. And not always such issues have fast and simple solution – it may be that you’ll have to reinstall Windows completely with all the applications you have… and also you may loose some or even all of your data!
3. Operating system works slowly and produces many bugs: This is also a common issue. Every Windows user knows that system works best right after the installation – when it is ‘fresh’. Later system becomes less productive because of registry changes, disk fragmentation, computer worms and viruses, different adware and spyware programs working in the background etc. Fixing the system would take a lot of time and would not return the system to the initial state. That’s why at some moment we may decide to restore our previously created Windows backup.
4. Accidental file deletion: That is the most harmless situation. In most cases you can just recover accidentally deleted files from the recycle bin. But what if recycle bin was already cleared? This is another way in which Windows backup software may become useful.

Strategy to be used in such cases:

First of all you’ll need to format your hard drive and reinstall the operating system with all the applications that you use. Install some Windows backup software also. If you have important data on your computer – copy it temporarily to external drive or network share. Reinstalling operating system and applications can take much time but as they say - “For every minute spent in organizing, an hour is earned.”
Once you have a fresh Windows installation with all the applications you need to create a full Windows backup and save it on some external location like USB hard drive. When that is done you’ll have a Windows backup with all the programs that can be restored at any moment returning you to a fresh installation. But what about data? Everyday you create, download and modify lots of files. If you restore the Windows backup we’ll get fresh system but will loose all files! To get around this you’ll need to schedule an incremental backup of your data folders right after the full Windows backup was made.
Incremental backup is different from full one – it will only add modified data to the backup saving you a lot of disk space.You can schedule the data incremental backup to run every evening saving all the folders that you use for storing your data. Then at every given day you would have a complete Windows backup and a bunch of data backups that store all your data. If something happens with the operating system or your drive you can just restore the full Windows backup first and then restore your data backup to the clean system and get back and running in an hour with minimum data loses. You can also restore the files from data backup without restoring full Windows backup – that would protect you against accidental deletion of important data. Using the recommendations above you can save yourself a lot of time and protect your data. The only last thing you have to do is choose the right Windows backup software.

What are ‘Spyware and ‘Adware’ items? Are they threats to computer security?

2009-03-24T00:50:00.000-07:00

You may have heard the name of ‘Spyware’ and ‘Adware’ in the field of computer and networking security. Are they really threats to PC health? Let us learn about your PC protection and PC security solutions. I just had, by mistake, a plug-in called Intelligent Explorer attach to my browser. What a nightmare! I have another article on this topic, but this brings home a point. Spyware or adware items are continually infecting computers. Most computers have no protection from them. Most frightening is the frequency of them. From the InfosecWriters web site, "According to a survey by America Online and the National Cyber Security Alliance, 91% of users questioned were familiar with the term spyware. Only 53% believed their computers were infected, but a scan found that 80% of their PCs had some type of spyware installed on them." It goes on to say…, “...The average number of spyware components per computer was 93 with one computer having well over a thousand."

What is Spyware?

“The term ‘Spyware’ is broadly defined as any program that gets into your computer without permission and hides in the background while it makes unwanted changes to your user experience.
Spyware is generally not designed to damage your computer. The damage it does is more a by-product of its main mission, which is to serve you targeted advertisements or make your browser display certain sites or search results. Some of them are called blaster spyware.
At present, most spyware targets only the Windows operating system (Internet Explorer).”
To be fair, spyware can be harmless, for example tracking cookies don’t do much. While such things infringe on your privacy, they don't really harm anything. Others, however, are extremely dangerous.

So what do you do about it?

No spyware program seems to do everything, but there are a lot of goods solutions out there that can help. Here is a list of some of the top Spyware removal software to look at:

1) Ad-Aware 6.0 Professional from LavaSoft (there is also a free version with less functionality)

2) Spybot Search & Destroy from PepiMK Software

3) Xoftspy form Pareto Logic

5) Spyware Guard from Javacool Software is a free program

4) Pest Patrol (now part of Computer Associates by acquisition)

5) McAfee Anti-Spyware

One thing is for certain: you do need to take spyware seriously. For some reason, too many people out there think anti-virus solutions are the end-all solution. They are not.

And, when all else fails?

Finally, as drastic as it seems, if your computer has been infected with a large number of spyware programs, the only solution you may have is backing up your data, and performing a complete reinstall of the operating system.

Increasing Broadband Connection Speed

2009-02-08T05:46:00.000-08:00

Today I will provide some tips that will help ADSL/Cable Modem users to increase their broadband connection speed in Windows XP
Broadband connection tweaking process incorporates the enabling of a special buffer in the computer's memory to better deal with Network Interface Cards (NIC) or the USB modem.
I recommend this tweak to users having 256 MB RAM or above due to some technical reasons.

Step #1 - Identify the IRQ used by the NIC/USB modem:

Follow these steps:

Open the System Information tool by running MSINFO32.EXE from the Run command.
Expand System Summary > Hardware Resources > IRQs.
Look for the listing made for your Network Interface Card (NIC) and note the IRQ next to the specified line.
In case of USB modems you will first need to find the right USB device used by your modem.

Then follow these steps:

Open the Device Manager tool by running DEVMGMT.MSC from the Run command.
Scroll down to Universal Serial Bus controllers and expand it.
Right-click the USB Root Hub and select Properties. Note that you might need to do so for all listed USB Root Hubs (If there is more than one) in order to find the right one.
In the Power tab, look for your USB ADSL modem. In the Resources tab, look for the assigned IRQ. This is the IRQ we are looking for

Step #2 - Modify the system.ini file

Follow these steps:

Run SYSEDIT.EXE from the Run command.
Expand the system.ini file window.
Scroll down almost to the end of the file till you find a line called [386enh].Press Enter to make one blank line, and in that line type IrqX=4096
where X is the designated IRQ number we found in Step #1.
Click on the file menu, then choose save.
Close SYSEDIT and reboot your computer.
After doing this, you will notice Speed Improvement.

Secrets of Windows-XP

2009-02-03T08:24:00.001-08:00

Today I will share some secrets of Windows-XP with you and tell you how to change some parameters and make good use of them.

Deleting System Softwares:

Do you know, XP hides some system software you might want to remove, such as Windows Messenger, but you can tickle it and make it disgorge everything. Using Notepad or Edit, edit the text file /windows/inf/sysoc.inf, search for the word 'hide' and remove it. You can then go to the Add or Remove Programs in the Control Panel, select Add/Remove Windows Components and there will be your prey, exposed and vulnerable

Increasing Band-Width By 20%:

Microsoft reserves 20% of your available bandwidth for their own purposes like Windows Updates and interrogating your PC etc

How to get it back:

Click Start then Run and type " gpedit.msc" without quotes. This opens the group policy editor. Then go to: Local Computer Policy then Computer Configuration then Administrative Templates then Network then QOS Packet Scheduler and then to Limit Reservable Bandwidth. Double click on Limit Reservable bandwidth. It will say it is not configured, but the truth is under the 'Explain' tab i.e."By default, the Packet Scheduler limits the system to 20 percent of the bandwidth of a connection, but you can use this setting to override the default."
So the trick is to ENABLE reservable bandwidth, and then set it to ZERO. This will allow the system to reserve nothing, rather than the default 20%.It works on Win 2000 as well.

Creating Shutdown Icon or One Click Shutdown:

Navigate to your desktop. On the desktop, right-click and go to New, then to Shortcut (in other words, create a new shortcut). You should now see a pop-up window instructing you to enter a command line path. Use this path in "Type Location of the Item" SHUTDOWN -s -t 01
If the C: drive is not your local hard drive, then replace "C" with the correct letter of the hard drive. Click the "Next" button. Name the shortcut and click the "Finish" button. Now whenever you want to shut down, just click on this shortcut and you're done.

Securing Your Computer System

2009-02-03T08:16:00.000-08:00

Now-a-days, more and more people are using their computers for everything from communication to online banking and investing to shopping. As we do these things on a more regular basis, we open ourselves up to potential hackers, attackers and crackers. While some may be looking to phish your personal information and identity for resale, others simply just want to use your computer as a platform from which to attack other unknowing targets. Below are a few easy, cost-effective steps you can take to make your computer more secure.

1. Always make backups of important information and store in a safe place separate from your computer.
2. Update and patch your operating system, web browser and software frequently. If you have a Windows operating system.
3. Install a firewall. Without a good firewall, viruses, worms, Trojans, malware and adware can all easily access your computer from the Internet. Consideration should be given to the benefits and differences between hardware and software based firewall programs.
4. Review your browser and email settings for optimum security. Why should you do this? Active-X and JavaScript are often used by hackers to plant malicious programs into your computers. While cookies are relatively harmless in terms of security concerns, they do still track your movements on the Internet to build a profile of you. At a minimum set your security setting for the “internet zone” to High, and your “trusted sites zone” to Medium Low.
5. Install antivirus software and set for automatic updates so that you receive the most current versions.
6. Do not open unknown email attachments. It is simply not enough that you may recognize the address from which it originates because many viruses can spread from a familiar address.
7. Do not run programs from unknown origins. Also, do not send these types of programs to friends and coworkers because they contain funny or amusing stories or jokes. They may contain a Trojans horse waiting to infect a computer.
8. Disable hidden filename extensions. By default, the Windows operating system is set to “hide file extensions for known file types”. Disable this option so that file extensions display in Windows. Some file extensions will, by default, continue to remain hidden, but you are more likely to see any unusual file extensions that do not belong.
9. Turn off your computer and disconnect from the network when not using the computer. A hacker can not attack your computer when you are disconnected from the network or the computer is off.
10. Consider making a boot disk on a floppy disk in case your computer is damaged or compromised by a malicious program. Obviously, you need to take this step before you experience a hostile breach of your system.