VoIP is probably something you have heard about if you are keen of new computer technologies. VoIP allows telephone calls over the Internet and due to the constantly improving Internet connections it is starting to replace traditional phone networks. VoIP is mainly used by businesses as they are more likely to have access to fast Internet connections, needed by this type of telephony.
Although the initial use of VoIP systems was to allow communication between computer users located in different places, the idea was developed even further and is now on its way to becoming a stand alone telephone network. VoIP has made calling any phone in the world as well as receiving phone calls from users connected to Local Area Networks or the Internet possible.
History
The idea dates back in 1995 and it was started by an Israeli computer enthusiast who managed to establish the first phone call between two computers. Later that year a software package called Internet Phone Software was developed and released and it was essential for a VoIP connection. VoIP users needed this software, a modem, sound card, microphone and speakers in order to be able to use the Voice over Internet Protocol.
The Internet Phone Software was responsible for the digitalization and compression of the audio signal prior to sending it over the Internet. It was also needed for its decompression and therefore VoIP communications were only possible between people using this software. Due to the fact that the whole system was at its beginnings, the sound quality was very poor and far from that of traditional telephony.
The potential behind this idea was easily understood so the technology was developed further in the following years. Gateways that allowed PC-to-phone connections were established as well as designated VoIP connections later that year. Calls using this protocol were even possible from standard phone sets once the connection had been established from a computer.
The protocol today
Quite a few VoIP services are available today, suiting any type of needs. While some are still computer dependent, phone-to-phone and PC-to-phone services are also available.
Although special USB compatible Internet phones were developed, the computer can be completely bypassed by Internet phones that link directly to a cable or DSL broadband connection via a modem.
The principles behind VoIP
In order to be able to send your voice over the Internet, it has to be transformed into digital data. The digitalization process is called 'sampling' and involves 'breaking' the sound into very small pieces that can be characterized by a number value. After this process has ended, the digital result is compressed and divided into small 1500 bytes packets that will be send over the Internet. Packets contain not only the voice but also data regarding their order needed for a correct reconstruction and data about their origin. Once the packets have reached the destination they will be reconstructed and the resulting digital data will be transformed back into analogue sound and played by the speakers.
A broadband connection is required due to the large amount of data that has to be transmitted over the Internet in a short time to avoid noticeable delays. This is the reason why the system is more popular among companies that already use and can easier afford such connections.
Introduction to Voice Over IP
Printers - A Practical Buyers Guide
Buying a printer can be a complicated business, there are more shapes, sizes and types of printers available to the home and small business user than ever before. Printers have also become specialised for their intended purpose.
It is no longer a case of "a printer is a printer". Printers are now designed to be good in a particular area rather than a "Jack-of-all trades", which will do everything.
An often overlooked issue, is the very serious consideration of cost of ownership, which is all about of how much it will cost to keep your printer running (see below). So making that decision on which printer to go for can be a seriously arduous task, especially if you are keen to buy a printer that is not only affordable to buy but also cheap to run.
So here is the information that you need to know and consider, but no one tells you! We have not expanded on which printer is the best at any given time because models constantly change and you can find that information in any current glossy PC magazine off the shelf. Instead, here you will find the good, bad and ugly bits from the different types of printers available so you can make an informed decision yourself.
Inkjet Technology
Inkjet printers form images by spraying tiny droplets of liquid ink onto paper. The size and precision of the dots of ink and the type and quality of the ink itself govern how good the print quality is. A quality inkjet printer can produce very near photo-quality images using specialist photo coated paper. In general there are two types of inkjet printers, those with the printhead built into the printer like Epson, Brother etc and those where the printhead is actually on the ink cartridge like HP and Lexmark. There are many arguments for and against both technologies, but in our experience we have found both to be very good, the major difference seems to be that the cost of running a printer using the "printhead" type ink cartridge is usually higher.
Inkjet ink is specially formulated for specific printer models and their purpose, much technology is involved in the development of these inks to improve print quality, longevity, drying speeds and printing speeds etc. Most inkjet ink is produced using dye based ink which can flow easily through the tiny nozzles of the printhead, this type of ink is good for photos and colour shades but not so good for longevity or solid vibrant colour, think of it like a water colour painting. In recent years pigment ink technology has advanced considerably to enable use in inkjet printing. Previously ink pigments were too large and would block up the nozzles. This type of ink is good for solid colours and longevity, think of it like an oil painting.
Manufacturers like Epson, HP and Jet Tec are now increasingly using a fusion of dye based and pigmented inks to create superb quality photo printing with vibrant colours and longevity too.
Inkjet printers use anything between two and eight ink cartridges to do their job. Generally speaking the entry-level machines use two cartridges, good all round machines use four and specialist photo printers use six or more. The two cartridge system works fine though can be a bit wasteful on the colour ink, so go for a four-cartridge system where possible especially if you do colour printing. The six or more cartridge systems produce outstanding photos, but can be costly and a pain to keep changing cartridges (printer does not work if any one cartridge is empty).
Inkjet printers are the best solution for most people and are usually the most cost effective way to print - unless you are printing large volumes.
Portable Inkjet Printers
These printers are small, lightweight and ideal for people on the move. Although the printing of high quality photographs is usually beyond this type of printer, basic colour printing is of good quality and the quality of text print is mostly outstanding considering the size of these tiny portable A4 printers. These printers are not suitable for high volume printing.
Inkjet Printers
The Inkjet Printer is the most commonly used type of printer among home and small business users. With excellent all round printing capabilities, from black & white text print and good colour prints through to very hi-resolution, high quality photographs using Inkjet Photo Printers. Inkjet printers are available from cheap entry level to high-end business use machines and can print from photo size prints to massive A2 and bigger sizes, there are models for occasional use and others for high volume print jobs too. One of the many great things about Inkjet printers is that you can use a wide variety of media to print on, including standard paper, photo paper, card, t-shirt transfers, canvas, projector film etc, achieving different looks and textures for your prints and print for different purposes. Most Inkjet printers are USB connections and not suitable for networks, although models are also available for networks and with parallel connections.
Multi-Function Inkjet Printers
Multi-Function Inkjet Printers have been built to meet the needs of home offices and small businesses. These excellent value machines provide multiple solutions in one compact and easy to use machine i.e. printing, scanning, copying and some also have built in fax machines too. Not only are these machines great for saving space on your desk, but they are also very good for printing too using the same technology as standard inkjet printers. The only thing you should be aware of is that you can only use one function at a time and if anything goes wrong with an "All-in-one" machine, you may lose the all the functions at once!
Laser Printers
Laser printers work in a similar way to photocopiers, except they use a laser instead of a bright light to scan with. They work by creating an electrostatic image of the page onto a charged photoreceptor, which in turn attracts toner in the shape of an electrostatic charge. Toner is the material used to make the image (as ink is in an inkjet printer) and is a very fine powder, so laser printers use toner cartridges instead of ink cartridges.
Laser Printers have traditionally been the best printing solution for heavy office users as they produce a very high quality black text finish and offer relatively low running costs. However, laser printers have advanced a great deal recently and their prices have steadily dropped, as a result there are now compact laser printers, multi-function and colour laser printers all at very affordable prices. Laser printers make sense if you need to do a lot of high quality black or colour prints, not photos. The great thing about a colour laser printer is that they can print a very good quality colour image on standard copier paper, so you do not need to use expensive photo paper for large jobs. Do check the prices of the consumables before you buy the printer as these can be very expensive for colour laser printers.
Laser printers are the best solution for people who are printing in large volumes, that is, in 100's of pages at a time or 1000's of pages per month. Colour lasers also take quite a while to warm up, so are not ideal for printing single pages.
Solid Ink Printers
Solid ink printers use solid wax ink sticks in a "phase-change" process, they work by liquefying wax ink sticks into reservoirs and then squirting the ink onto a transfer drum from where it is cold-fused onto the paper in a single pass. Solid ink printers are marketed almost exclusively by Tektronix / Xerox and are aimed at larger businesses and high volume colour printing.
Solid ink printers used to be cheaper to purchase than similarly specified colour lasers and fairly economical to run owing to a low component usage, today it is not necessarily any cheaper than a colour laser printer. Output quality is good but generally not as good as the best colour lasers for text and graphics or the best inkjets for photographs. Print speeds are not as fast as most colour lasers.
Dye-Sublimation Printers
Dye-Sublimation printers use heat and solid colour dyes to produce lab-quality photographic images. Dye-Sub printers contain a roll of transparent film made up of page-sized panels of colour, with cyan, magenta, yellow, and black dye embedded in the film. Print head heating elements vaporize the inks, which adhere to a specially coated paper, as the ink cools it re-solidifies on the paper. Colour intensity is controlled by precise variations in temperature.
Dye-sublimation printers lay down color in continuous tones one color at a time instead of dots of ink like an inkjet, because the colour is absorbed into the paper rather than sitting on the surface, the output is more photo-realistic, more durable and less vulnerable to fading than other ink technologies.
The downside of Dye-Sub printers is that they are generally more expensive to buy and run, usually limited to photo sized prints only and can only print onto one type of specialised paper as well as being quite slow to print.
Dye-Sublimation printers are best for those who want to link up their digital camera to a purpose built printer and print out the finest quality photos at home without fuss.
Dot Matrix Printers
Dot matrix printers are relatively old fashioned technology today with poor quality print, slow and very noisy output. This type of printer is no longer used unless you wish to create invoices using the continuous paper with holes on both sides. The good thing is that they are very cheap to run!
Cost of Ownership
Many printers today are very cheap to buy, but people are sometimes shocked to discover the cost of replacing the consumables (ink or laser cartridges, imaging drums, fuser, oils, specialist papers etc). The cost of replacing the ink can sometimes cost more than the printer itself! This is one of the most commonly overlooked factors when printers are reviewed and yet one of the most important things to consider before handing over your hard earned cash. Tests run in 2003 by Which? magazine famously compared the cost of HP's ink with vintage 1985 Dom Perignon.
A Sheffield City Council report aimed at helping schools decide on the best-value printers to buy, calculated total cost of ownership over the lifetime of a printer (not sure how long that is!). Adding up all the running costs, ink or toner, paper, maintenance and even electricity, SCC worked out that a colour inkjet costs approx 38p per page to run compared to a colour laser which costs approx 7p per page. Sheffield City Council advised its schools that if they printed more than three colour pages a day (assuming a 40-week academic year) they should buy a laser.
These figures cannot be taken hard and fast due to the many variables involved, but it is generally accepted that the cost per print of a laser printer is cheaper than that of an inkjet, which is in turn cheaper than that of a sub-dye printer. However, you would have to do a fair amount of colour printing to take advantage of the economy offered by a laser printer.
Summary
When buying a printer, firstly carefully consider its use, is it mostly general printing or for photographs, is it for occasional use or high volumes, will it be a stand alone device or connected to a network? Then using the guideline information above you will be able to decide on which type of printer is most suitable for you at the time.
Boost Your Career And Benefit From A Microsoft Certification Or Two Or Three!
You went to college and thought you were prepared for the job market. If you are going for entry-level work, yeah, you are prepared. However, to really get ahead, you need Microsoft certification, whether it is an MCP, MCSA, MCSE or any other string of letters. Quite a few people will go for multiple certifications to broaden their experience and scope of possible job opportunities.
Some of the Microsoft certifications require you have to have at least one year of practical experience in order to pursue a certification, namely an MCSE or Microsoft Certified Systems Engineer. It is important to have that experience that these certain certifications require because the training, like the MCSE training and the MCSE exams that follow, are very intense. In fact, some people will not only partake of the standard MCSE training, but also MCSE boot camps for more in-depth studies into their certification.
One standard benefit to having a Microsoft certification is that it is a great basic means of analyzing the aptitude of an employee. If you are a manager or owner in a business, you want some way to evaluate that employee’s skills. And if you are the employee, you know that your boss recognizes your abilities.
If you are on the hunt for a new job, then potential hiring managers and employers have a basis in which to assess your qualifications. Without that Microsoft certification on your resume, these employers would have no idea about your skills and most likely would consider someone else, someone with a certification, for the position you were aiming for.
If you do not have much hands-on experience in your field, but you do have the Microsoft certification to prove that you know the material, you would also have a leg up on anyone else applying for the same position that may have more hands-on experience, but no certification. For some reason, that certification, those little string of letters like MCP or MCSE, hold a lot of power.
Yet another benefit to holding a Microsoft certification or two is the money aspect of it all. Sure, you shelled out some major bucks to fund your education in those MCP courses or that MCSE training, but consider it an investment in yourself. With certification, you can bargain a higher salary and even reimbursement for your training!
Many professionals in the IT field or in a company in which you work in an IT department could benefit from Microsoft certification. Do you work as an Administrator for a network, mail or web server? Are you involved in the security of networks and the internet? Any of those positions and much more benefit with additional training and certification. Just think money! It is the biggest motivator. The more you know and can bring to a position, the more money you stand to make.
So think about going for your MCSE or MCP certification or any number of others available. More training; more knowledge; more money ... sounds like a no-brainer! Go nuts and get certified today!
Feature Overload--Why Consumer Electronics Are So Complicated
It seems like everything is so complicated these days, especially anything electronic … which is more and more products everyday.
Why are they so complex? "Hey, our cell phone takes pictures, sharpens knives, mows the lawn, pays your bills, steers your car, and cooks dinner, all by voice command!" Give us a break!
Unfortunately, the reason so many electronic products are stuffed with features is that it is relatively cheap to add features to them! Do we consumers really want or need those functions? That is an entirely different question. Often, the answer is no. But the manufacturers add them, in many cases, simply so they can advertise that they have more features.
It costs a lot more to carefully determine what features are most wanted and to design products so that they are feature-rich, yet easy and intuitive for people to use. That is why this vital step is often shortcut.
Ever had trouble figuring out how to program your VCR? Did you ever think that perhaps it's not really your fault? It's the fault of the engineers who designed a lousy user interface to the product. And you think they are bad? Try using a combination VCR-DVD player!
There is second reason why manufacturers keep cramming more questionable features into products. In the case of products like cell phones, sales have slowed down because most people who wanted one have one. So, the phone manufacturers keep adding features in order to try to find ones that motivate people to buy new phones. They keep looking for that latest cool feature that people will be willing to buy a new phone to get.
Similarly, digital camera manufacturers keep coming out with cameras with more and more megapixels. Two megapixels, then 3.2, then 4.0, then 5, now 6, 7, even 8. Do consumers need 7 or 8 megapixel cameras? Not in the least. For shooting snapshots or sharing pictures online, a 3.2 megapixel camera is more than adequate. Really.
Why then, do manufacturers keep extending the capability? It is as we said above: 1) so they can advertise they have it, and 2) to try to get people to stick their old camera in a drawer and buy a new one.
Our advise: It pays to look carefully at the features being offered in the products you are interested in. Don't assume that a product with more features (or higher numbers) is the better choice. Often it is not, it is just more complicated to use! And, there is more to go wrong.
Bloatware
There is a similar phenomenon in software. It is called "bloatware." Programs that are overloaded with features, especially those not essential to the basic purpose for the software, carry this moniker.
When I was in the software industry and we were working on the next versions of software products, the programmers would sometimes come and say, "Hey I can add such-and-such feature with only 100 lines of code," or some such number. That’s not much, since a software program can have hundreds of thousands of lines of code. But often it was a feature the users of that software had no need for. Playing consumer advocate, I'd ask why such a feature would be needed. If the answer was questionable, I'd tell them to leave it out. Too often, though, those features make it into software products, and they become bloated with unnecessary features. Bloatware.
