What Are IP Phones?

Posted in Computers on October 20th, 2009 by Computers

In a world where people are only just starting to become aware of VoIP, the term ‘ phones’ may be a mystery to most. Actually, they’re an addition to existing technology that uses standard operating hardware to access a new way of making phone calls – Voice over Internet Protocol.

An phone is an Internet Protocol phone. It allows the user to communicate over networks such as Internet or Intranet connections, rather than using the more traditional phone system. A traditional phone transfers the communicators’ voices through a ‘circuit switching’ method. In this scenario, the caller and receiver are connected through a continual electrical circuit. Voice transfer using this method is relatively slow as the data is transferred in large amounts in one go, often resulting in a slight sensation of a ‘delay’ or even an echo effect. With long distance calls, there is also the problem of call interruption or even disconnection, particularly if the circuit cannot cope with the volume of data being transferred.

The phone is different. This system uses a ‘packet switching’ system where an analogue voice signal is converted into digital data packets, which are much smaller in size than the more traditional circuit switching packets. These data packets are then sent individually through the Internet to the receiver and reassembled in order and converted back into voice. This has two major advantages. Firstly, it makes the whole process much quicker, with less chance of the datastream failing half way through and breaking the connection. It also makes it much more secure as the individual data packets are not reassembled until they reach their destination, preventing hackers or eavesdroppers from listening in on the conversation or extracting sensitive data.

An phone can be used anywhere in the world, as long as you have an Internet connection. This takes away the constraints of the traditional phone and all the receiver needs is a normal phone to accept the call – there is no need for an Internet connection or even a compatible phone to be able to receive an phone call.

The primary reason that people are now starting to take phones seriously is the cost. Voice over is considerably cheaper than traditional calls, particularly if you are making long distance calls. Because the use of the Internet connection means that the actual location of the call is untraceable, long distance charges cannot and do not apply. The only additional expenditure is the one-time installation of hardware and software to be able to access the system. If you decide to go through a VoIP provider, a capped monthly charge (usually considerably less than conventional landline phone packages) will give you unlimited calls to selected destinations worldwide. Because you are only actually paying for the Internet connection rather than the phone call itself, the end cost is far lower and is particularly useful if you do business with companies abroad or have family and friends overseas.

The only disadvantage of phones is that they may not be able to penetrate some Internet firewalls. So if you are planning to make a VoIP call to another recipient, it may pay to check via email first that the call will be allowed through your recipient’s firewall system. Also remember that hardware, working on a domestic power supply, requires some sort of power system in case of a power outage (which would instantly disconnect your call). A personal UPS (uninterrupted power supply) may be a worthwhile investment if you intend to use VoIP technology on a frequent basis.

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Why Mobile Phone Use in Aircraft Are Not Allowed ?

Posted in Computers on July 27th, 2009 by Computers

Do you know why are not allowed to be used in aircraft during flight? One reason for this is channel reuse. Actually, if we go to technicalities, it would be quite hard for us to understand the many technical jumbo mumbo that are there, so let us just put it on the simplest way of explanation that we can. You see, our are designed for use with low power output. This is because the transmission and reception of signals are based on channel reuse. What I mean about the word channel are the different frequencies that a uses to transmit and received signals like for example 120 kHz or 100 MHz. These channels of frequencies are expressed in hertz. A particular operating at 100 MHz. will have interruption of signal if another also operating at the same channel will be using the same cell site or tower.

With regards to cell sites or towers, I think you are more or less particular about them already. They are like very small Eiffel tower like construction that you can see jutting out of the farm landscape, sometimes even inside cities and urban areas. In fact, in our locality, a cell site or tower is now under construction in the backyard of a house, several blocks away from our residence.

Now, going back to why are not permitted to be used in aircraft during flight, because of channel reuse. The reason why can be used by many without interruptions even when they operate on the same channel is channel reuse. Because are designed to have limited power, a in operation utilizing the nearest cell site or tower would not be able to utilize another cell site or tower even if that cell tower is only several kilometers away. This will make possible for other having the same frequency with the first to use the other cell site or tower without interruption to the signal of the first , even if it has the same operating frequency as that of the first .

It was pointed out by authorities that if you are using a in an airplane and the altitude of the plane is within range of the many ground cell sites or towers, the speed by which the plane is moving will dislocate the receiving and transmission of signals on most cell sites or towers resulting to interference of signals to other users operating on the same frequency as your . In effect, the result will have a negative effect on the fundamental operation of which is channel reuse. This is the basic reason of most governmental regulating agencies why they do not allow to be used in aircraft during flight.

The second reason would be in terms of electro magnetic interference to electronic devices of the airplane. It was likewise pointed out by authorities that a plane in flight even if it would still be within range of ground cell sites or towers, will make the transmission and reception of signals to and from a weak because of the speed of travel. This will make the unit to automatically use more power to send and receive signals from cell sites or towers which would have the possibility of affecting the workings of electromagnetic devices of the airplane. So, for the safety of all, why don’t we just shut off our during flight?

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Using Vehicle Tracking to Cut Costs For Your Business

Posted in Computers on July 19th, 2009 by Computers

For fleet managers, the installation of a vehicle tracking system into their fleet can lead to substantial cost savings and a more efficient fleet. The initial investment of a high quality system may be expensive, but GPS tracking can soon show a return on your investment by reducing excess mileage, preventing out-of-hours use and even saving on insurance premiums.

Vehicle tracking systems are designed for tracking both vehicles and people. Although fleet managers may initially meet some resistance from fleet drivers concerning the introduction of a vehicle tracking system, if the advantages are explained carefully most fleet managers say that the installation of the system is then welcomed by hard working drivers. Those who are perhaps taking advantage of an ‘out of sight, out of mind’ mentality will find that their actions are curbed, saving the company money as a result.

One of the main benefits of having a vehicle tracking system installed into a fleet is the reduction in insurance premiums that it may generate. Because GPS tracking means that the location of the vehicle is constantly monitored, stolen vehicles can be recovered quickly, minimising the risk of excessive damage. Vehicle theft costs insurance companies millions of pounds in claims every year, and the cost to the individual business (particularly small operations) can be far higher through the interruption of normal business, paying for replacement vehicles and loss of customer confidence through delays and items lost in transit. GPS tracking uses a triangulation algorithm to locate a vehicle quickly and good tracking systems can even issue a silent alert if a vehicle is moved when it should be stationary. This alert can be instantly relayed to the Police with a co-ordinate location, allowing them to recover the vehicle quickly.

Fleet management is not just ensuring that everyone is where they’re supposed to be and the vehicles are in good operational order. It’s also about maximising , reducing costs and maintaining good customer relationships. It’s also making sure that your public image on the road is a good one, particularly if your company vehicles carry recognisable company livery or are sign-written. Vehicle tracking systems can help to improve by ensuring that your drivers are using the most efficient routes and are not wasting fuel through excessive speeding (which can also damage your company’s reputation with ordinary members of the public). Using a comprehensive GPS tracking system, fleet managers can redirect the closest vehicle to a pick up, reducing waiting time for the customers and improving customer relations.

Vehicle tracking can also minimise the temptation for drivers to use their vehicles ‘out of hours’, thus increasing the cost to the fleet manager through excess wear and tear on the vehicles and increasing the potential for the vehicle to be damaged or stolen. If drivers know that the exact location of the vehicle is being monitored and that detailed information is being fed through to a central system as to the vehicle’s movements they will be less inclined to chance disciplinary action through inappropriate usage of company vehicles. All of this adds up financially, and by preventing these excesses through efficient fleet management and the incorporation of cutting edge GPS tracking systems, fleet managers can be responsible for saving the company a considerable amount of money.

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Cisco CCNP Certification / BSCI Exam Tutorial: Comparing IRDP And HSRP

Posted in Computers on July 15th, 2009 by cahyo

To the , you need to know the difference between IRDP and HSRP. While they have the same basic function, the operation and configuration of each are totally different.

The aim of both is to allow hosts to quickly discover a standby when the primary fails. IRDP is commonly used by Windows DHCP clients and several Unix variations, but you do see it in as well. IRDP is defined in RFC 1256.

IRDP will multicast Hello messages that host devices hear. If a host hears from more than one IRDP , it will choose one as its primary and will start using the other if the primary it’s chosen goes down.

HSRP is a -proprietary protocol that is designed for quick cutover to a secondary if the primary fails, but the host devices don’t “see” either the primary or secondary . The hosts use a virtual as their default gateway. This virtual has its own and MAC address! All the while, the chosen as the primary is actually the one doing the routing. If the primary goes down, the secondary quickly takes over with no major interruption to network services.

The HSRP communicate by multicasting updates to 224.0.0.2, and its through these hellos that the HSRP decide which is primary and which is secondary. HSRP is defined in RFC 2281.

The configuration of each of these will be covered in a future tutorial. In the meantime, I urge you to read the RFCs mentioned in this article, and visit www..com/univercd to read about the configurations and options available for both of these vital .

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Appointment Scheduler Software – No Exception To Sophisticated Technology

Posted in Computers on May 27th, 2009 by Computers

The sophistication of technology today has progressed so much so that can encompass more . Appointment scheduler software is no exception. An appointment scheduler software is designed to meet the needs of all varied health care practices, businesses, and companies, to run their offices. And for those who have more than one branch to manage, you shouldn’t have to buy a separate program for each location. For appointment scheduler software, one should definitely fit all.

One of the most important features on an appointment scheduler software is the option of making online appointment setting possible to your clients. This feature, alone, is a very powerful incentive for investigating browsers to choose your business over others. Without having to deal with the discouraging interruption of leaving the computer to get on the phone, calling an office just to wait for the receptionist to finish helping in-house patrons or waiting for the right party, potential clients can just set their appointment themselves. That kind of instant gratification can encourage higher inquiry response.

Sometimes the optimal method of appointment setting for a business is multiple appointments for the same time slot. Businesses like a chiropractor’s office or a touring agency the most when they can set their appointments like this. With the to mass schedule and yet treat each appointment individually in regards to designated room and equipment, or destination and accommodations, you are empowered to meet each, unique need of your clients. And even if you decide this method is not best for your company, you can back or try an entirely different method without the fear of losing any data.

Clients aren’t the only ones that need to have a schedule. Employees and office staff also from the use of an appointment scheduler software because it clearly delineates the days and times they are needed at work. This is especially helpful when you share staff among multiple locations. You can schedule your staff without the worry of simultaneously scheduling the same employee at two different locations.

To run a single business or an entire chain from one location, an appointment scheduler software was designed to afford managers the accessibility needed to do so efficiently. To program your website that befits your company’s needs. And to schedule your staff with an arrangement that accommodates all. You can be assured that your business’ calender, managerial, and task setting needs will be met with an appointment scheduler software.

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