Medical Coding History – From Paper to Medial Coding Software

If we define medical coding as the assignment of alphanumerical characters to diagnoses, diseases, and treatments, then medical coding has been traced back to the 1600s in England with the London Bills of Mortality. A more standardized system of coding was developed for classifying death at the tail end of the 19th century. In 1893, Jacque Bertillon, a statistician, created the Bertillon Classification of Causes of Death, a system which was eventually adopted by 26 countries at the beginning of the 20th century. Shortly after the Bertillon Classification system was implemented, people began discussing the possibility of expanding the system beyond mortality as a way of tracking diseases.

By the middle of the 20th century, the World Health Organization (WHO) adopted a goal of a single global classification system for disease and mortality, entitled the International Classification of Diseases, Injuries, and Causes of Death (ICD). This classification system is updated every 10 years. The latest revision, ICD-10, is scheduled for adoption in the United States in 2013.

What started out as a small set of medical codes has evolved into a complex system that was initially standardized by the American Medical Association back in 1966 with current procedure codes (CPT) codes that are updated annually.

In the late 1970s, the Healthcare Common Procedure Coding System (HCPCS) was developed based on CPT. HCPCS has three levels of codes: Level One is the original CPT system. Level Two codes are alphanumeric and include non-physician services such as ambulances and other transportation as well as patient devices such as prosthetic devices. Level Three codes were developed as local codes, and were discontinued in 2003 in order to keep all codes relevant worldwide.

Recently, medical coding systems have been expanded to include other medical specialties. For example, there are coding systems related to disabilities, the dental field, prescription drugs, and mental health.

As the coding systems have become more complex and diverse, the need for training of medical coders has grown exponentially. Private training schools and public colleges throughout the country have developed certification programs. In order to be awarded a certificate, students must obtain a two-year degree from an accredited medical coding school and pass an exam given by the AHIMA.

Over the past 20 years, many coding processes have shifted from a paper-based system to a computer-based system using medical coding software and medical billing software. Many companies sell complete medical software-based coding solutions and myriad of products for specific medical disciplines, such as products that are specifically tailored to skilled nursing facilities, physicians, hospitals, surgery, cardiology, and more.

As medical facilities and professionals begin preparing for the conversion to ICD-10 in 2013, the need for more sophisticated medical coding software solutions and qualified medical coders will continue to grow.

CPT is a registered trademark of the American Medical Association.

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The Importance of Educational Software in Educational Institutes

Internet has expanded its dimensions like anything. The incredible expansion of the web world along with its easy and affordability of integrated technology have come together to create a new learning methodology of Educational Software. Nowadays, the task of carrying out educational projects and disseminating education is not at all futuristic or alien. This have not only become an important part of the educational setup but also of the business world. The facility to link with the internet in a reasonably priced and competent manner was the basic reason for this tremendous growth of this. Nowadays, education software available in comprehensive package forms for colleges, schools, Universities and even home use.

With time, educational institutions have become more diverse and therefore they cannot risk being simple temples of education. There are vast varieties of activities in educational institutes like admissions, curriculum management, library management, placements, hostel management, finance management and a number of other requirements. It is in view of these burgeoning requirements of schools and higher educational institutions that Educational Software have become popular nowadays. This software can address all the requirements of an educational institute starting from student curriculum management to school bus tracking system to Biometric Attendance System to Student Information System to Library Automation Systems.

Education Software is nowadays constituents of a school’s identity as they are capable of delivering all the associated tasks. Present day software even provides the facility and access to parents to keep a bird’s view of their kid’s progress in the classroom. The Student Information System enables parents to monitor the curriculum of their children and receive feedbacks from the teachers. Intelligent Library Management System allows easy access to library records.

Another aspect of education software is their Bus Tracking System that ensures the safety of students. It is a path breaking integration into this software. Nowadays, they have become quite affordable integrating advanced GPS applications into the software. They are effective tools for the school management as well as the parents, who want to know whether their students or kids are safe while travelling from school to home and vice versa.

The curriculum management component of this is capable giving an interactive learning experience to students. Nowadays, most of the education software is capable of developing to the next level as and when students grow in their knowledge. Online tests and evaluations have become important tools used by such software in order to test the level of students. It can even take the form of a game in order to stimulate the mind of children giving them real demonstrations of subject matter. Educational Software can now be found for students of all ages and for all subjects.

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8 Criteria to Choose the Best Antivirus Program For Your Needs

There is no best antivirus program in general. You can make the best choice of your antivirus software depending on your goals, your needs and your environment. In order to choose your best antivirus software you should look at vendor information, independent antivirus certifying agencies reviews, as well as other sources. Here are the essential criteria for the right choice.

1. Compatibility
Antivirus program has to be compatible with your PC configuration. Your PC must meet hardware and software requirements of antivirus solution.

2. Range of Protection
Antivirus software should protect your PC from as many threats and on as many viruses as it can: viruses, worms, trojans, spyware, keyloggers, adware, rootkits, password stealers, phishing attacks, spam and others.

3. Effectiveness
Antivirus protection delivery by antivirus program should be effective and efficient. You may find and compare test results released by independent antivirus certifying agencies: Virus Bulletin, AV Comparatives, ISCA Labs, Westcoast Labs and others. If some antivirus solution was scored by these agencies high and consistently near the top, then you really can not go wrong with this top rated antivirus software.

4. Easy Installation
Good antivirus program has a prompt and easy installation. Interface should be clean, easy, and intuitive to use.

5. Easy to Use
Most users want to "install and forget" their antivirus software. So the best antivirus solution should have default configurations acceptable for most users. And at the same time good antivirus program can be easily configured and tweaked by advanced users.

6. Features
The best antivirus programs have the large features set that may include:
– list of compatible versions of Operational systems and platforms,
– amount of used system resources,
– using of proactive protection without false positives and with effective utilizing of system resources,
– availability of laptop battery saving mode,
– bootable rescue disk,
– silent gamer mode, and other available options.

A comprehensive features set adds strength to antivirus solution.

7. Update
The best security solutions have Automatic Update option and automatically perform updates every hour or "as needed updates" to keep virus definitions and program code up to date.

8. Support
The best security programs have a comprehensive online and offline technical support. The program vendor should provide online knowledge base, FAQs, tutorials, user forums. The best sellers provide 24/7 support so you can ask your questions by phone, email or chat at any moment.

The best for your needs antivirus program delivers you the best security and usability with a minimal outlay of your time, money, or your PC system resources.

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What Requirements Does a Dot Net Developer Need to Fulfill?

Microsoft Dot Net is a useful software development component. It provides tools and libraries to the software developers so that they can create Windows-based applications in a more efficient manner. A Dot Net developer is a software programmer who has specific skills using .Net to develop software and computer applications. For people who are in the midst of looking for developers for your projects, there are some areas you need to take note. You are advised to look for competent programmers who can really assist you to complete your tasks successfully.

First thing first, you need to be clear about the responsibilities of a .Net Developer before you start looking for suitable candidate. Seriously speaking, the programmer is required to:

• Work hand in hand with other software engineers and architects to develop a logical series of instructions referred to as programming code for the computer to communicate with the networks, applications and databases.

• Create new software applications to suit the business needs

• Modify, repair, test and enhance existing applications

After knowing what the developer is required to do, the next area we need to take into consideration is the academic qualification. In general, a programmer should have degree qualification in computer science, information technology or any related discipline. If the programmer is not a degree holder, you may take a look at his or her working experience. If the candidate has extensive experience dealing with .Net development tools, you can consider getting him or her in. Check with the candidate whether he or she is familiar with maintenance of ASP Applications, e-Commerce solution, online education and learning, social networking sites, corporate web applications, and so on.

At the same time, a good dot net developer must be competent in carrying out all the important tasks. It is a must for him or her to have the following skills in:

• Classic ASP

• Microsoft SQL 2000 / 2005

• MS Access

• JavaScript, XML, DHTML, AJAX and CSS

• VBScript and JScript

Frankly speaking, if the programmer does not have the above mentioned skills, most of the employers in the job market are not willing to hire him or her.

Besides the skills, we should also take serious consideration on the general qualities of the programmers. They should have qualities as follow:

• Good passion in work

Having great interest in work is important. The programmers should love and enjoy what they are doing.

• Good learning attitude

Learning is a continuous process. We can’t stop at certain stage. Good developers must have positive attitude in learning. They must always grab the opportunities to learn new technology so that good applications can be adapted.

• Some “intelligence”

Honestly speaking, intelligence is something very subjective. What I mean here is the “personality” of the person. Being a programmer, he or she must be smart and sensitive to respond to all changes. It is important for a programmer to be open-minded and willing to take new challenges from time to time.

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Microsoft Access and Medical Private Practice

For physicians medical office software installation could be nerve-wracking, not because they want to avoid electronic medical records, but because the majority of the software packages are too complicated and very expensive for them.

The good news is, you can make your medical office software system uncomplicated and relatively easily maintained with one of the popular database software packages being used today, the Microsoft Access.

Microsoft Access is a relational database system developed by Microsoft. Microsoft Access is one of the easiest and most flexible database management solutions for the medical office and provides data validation and user-friendly features on data entry screens. It has been the dominant lightweight database system used for the last decade and has continued to grow with additional features. Access is a productive and very customizable solution for small medical practices and comes with MS Office (or standalone). However the next step up in a medical environment would be MS SQL Server but small medical offices usually only has need of a lightweight application and the added functionality with MS SQL Server, comes with a heavy price.

With this relational database system you can be up and running in one hour, which means that it is not necessary for your practice to spend lot of money to purchase, configure, update and maintain an SQL Server solution. Microsoft Access includes without any additional costs, points of integration with popular software packages including: Microsoft Word, Excel & Outlook and provides a free runtime version.

MS Access network setup is very easy. A medical office with 2-8 users is up and running within ten minutes, while installation and application maintenance is extremely simple. Virtually any user with a basic knowledge of Microsoft Access can handle all maintenance procedures without the assistance of IT personnel.

Keep also in mind that SQL Server is the flagship database system from Microsoft and it is suitable for use in environments with up to thousands of users. Microsoft Access can handle 2- 8 users and it is limited to 2 GB data storage.

We are convinced that the best way for private medical offices around the world to enter the world of electronic medical records is to purchase a professionally designed but inexpensive and affordable Microsoft Access based software solution.

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How Useful is CAD Software to Engineers and Architects?

The emergence of advanced technology has made people today dependent on machines. Using computers and software, for example, is a very common illustration of this. Computer experts are coming up with more and more software to make more and more jobs easier.

A more specific illustration of this can be found in the modern approach towards engineering and architecture. These days, professionals in these fields use CAD computer software which is a program that allows them to create designs faster, easier and with more accurate measurements. Aside from the convenience that CAD software brings, it also helps put architects and engineers ahead of their competitors. CAD, which can render designs that are two-dimensional or three dimensional, stands for Computer Aided Design and has been in use since 1982.

So how does CAD computer software work? And what does it do exactly to help engineers and architects? The program is actually multifaceted in the sense that there are many ways it can help. To make CAD work will require, however, a careful study of its features and the many ways it can be used. It is rather a complex yet flexible and highly functional program.

This article will not be enough to discuss the various ways that CAD works but pinpointing its advantages could give some very good ideas. One great advantage of CAD computer software is its easy-to-use tools in the creation and alteration of designs. Obviously, this is so much better than the old fashioned way of using a pencil and eraser directly on paper. This method of designing is obviously so much easier and engineers and architects simply have more time to finish other tasks. In other words, high productivity is going to be the main end result of using CAD.

Before the design is actually printed on paper, CAD also allows both the design professional and the client to preview what has been finished so far. Any alterations can be made simply by manipulating the drawing through the use of the software. With CAD, it is so much easier to spot errors because the designs can be rendered exactly as they would be in reality. Hence, modifications can be done even before printing, thus, allowing one to save.

With the tough competition that everyone has to face these days, it is wise to take advantage of new technologies that can help put them ahead in the race. While traditional methods hold a significant part in the history of design, advanced tools such as CAD software should only be welcomed as man’s way of furthering development in a field of expertise that he himself has created long ago.

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History and Components of a Modern Mainframe Computer

Mainframe computers are critical for some of the largest corporations in the world. Each mainframe has more than one modern processor, RAM ranging from a few megabytes to multiple-score gigabytes, and disk space and other storage beyond anything on a microcomputer. A mainframe can control multiple tasks and serve thousands of users every second without downtime.

The chief difference between mainframes and other computing systems is the level of processing that takes place. Mainframes are also different in terms of data bandwidth, organization, reliability, and control. Big organizations-banking, healthcare, insurance, and telecom companies, etc.-use mainframes for processing critical commercial data.

In this article, we discuss the evolution of mainframe computers and their components.

History of mainframe computers

IBM developed a critical part of mainframe computing, the Automatic Sequenced Controlled Calculator (ASCC) for arithmetic operations, in 1944. From the late 1950s through the 1970s, several companies manufactured mainframes: IBM, Burroughs, RCA, NCR, General Electric, and Sperry Rand, for example. Since then, System / 390 by IBM is the only kind of mainframe in use. It evolved from IBM's System / 360 in 1960.

An Early mainframe occupied a huge space. New technologies have drastically reduced the size and cost of the hardware. A current-generation mainframe can fit in a small closet.

Components of a modern mainframe computer

Like a PC, a mainframe has many components for processing data: operating system, motherboard or main board, processor, controllers, storage devices, and channels.

• Motherboard: The motherboard of a mainframe computer consists of a printed circuit that allows CPU, RAM, and other hardware components to function together through a concept called "Bus architecture". The motherboard has device slots for input cards and cable interfaces for various external devices. Where PC motherboards use 32- or 64-bit buses, mainframes use 128-bit buses. General instructions regarding the internal architecture help the motherboard connect to the other devices and retrieve data using binary computation.

• Processor: A CPU acts as the central processing point in mainframe architecture and includes an Arithmetic Logic Unit (ALU) for performing arithmetic calculations. It also works as a controller for the bus architecture and handles traffic and data requests. The processing power of mainframes is much higher compared to PCs, so that they can handle huge amounts of data.

• Storage devices: Storage devices are for entering, retrieving, storing, and recording data. Many are external devices, such as hard drives, tape drives, and punch card readers, all connected to terminals of the mainframe and controlled by the CPU. Their capacity for data storage can be hundred or even thousands of times that of a PC.

• Communication controllers: Communication controllers allow remote computers to access a mainframe. With the help of networks, LAN or WAN, communication controllers establish connections with various devices, perform data transmission over communication channels, and keep track of users at terminals.

• Channels: The "channels" are the cables used to connect the CPU and the main storage to other parts of the system and make sure that data is moved in a systematic way without losing its integrity.

Modern mainframes have advanced features such as expanded service management capabilities, cross-platform integration facilities, etc. And so are suitable for critical data center operations. The cost of maintaining modern mainframes is much less compared to older models.

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Can You Upgrade a Maya Student Version to a Full Commercial Edition?

The Maya 3D software from Autodesk has long-been a staple tool for the production of the highest level of Visual Effects and animation for Oscar-winning blockbuster movies, TV shows and video games.

Students who are looking to secure themselves commercial work upon graduation these days typically need to show some familiarity with this software…ideally the more the better, since most companies these days use Maya as their main software package, and many have it deeply integrated into their own proprietary pipelines and tools – meaning that the situation is unlikely to change for the foreseeable future.

Students who take the opportunity currently afforded them of purchasing a copy of the Maya Student Edition do well since they are able to improve their skillset on the full Unlimited version of the software, and do so at a huge discount (the student edition typically retails for around $350).

However, a number of students wonder if they also qualify for a discount later on if they wish to upgrade to a full commercial edition of the Maya software. Jumping from graduation to commercial work can be a challenge, so any way to alleviate the expense of setting yourself up as a freelancer is more than welcome…but can it actually be done?

Upgrade Maya Student Edition To Commercial License?

Yes, you’ll be pleased to know that there is a program available where current owners of a Maya student license are able to upgrade to the full commercial license at a massive discount of around 60%…in other words, a full commercial license of Maya would typically cost around $3,900, but student license holders are able to upgrade their current license to a full commercial one for just $1,300.

This is huge, and can be a real lifesaver for folks who want to go it alone and start their own freelance business but are wary of the huge costs involved.

In fact, if you’re smart about it and don’t mind a little negotiation, the license could even be purchased with a down-payment from your first client before you even begin working on their project.

Such a huge discount on the student to commercial upgrade is a great incentive for students, especially at this economic time, and it also makes purchasing the Maya student edition in the first place a sensible option, since you get access to these kinds of discounted upgrades.

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Determining the Best Type of Fastener to Use For Outdoor Furniture Construction

If you want to learn about selecting hardware for your next outdoor furniture project, then you'll want to read this article. Specifically, I'll be telling you about what type of hardware will perform best, why the type of metal used for fasteners and the finish used are important considerations, and how properly protecting or limiting exposure of your furniture to wet and winter conditions can increase Life span. After you're done with this article you will understand that the best choice of hardware for your outdoor furniture project is dependent on furniture style, material used for construction, selected location for the furniture and budget.

Selecting proper hardware for your furniture will help ensure a long life span, as well as improve the overall appearance of your furniture. Part of the problem is knowing what hardware to select when there are so many options available at the hardware store. The typical Lowes or Home Depot carries a huge selection of stainless steel, hot dipped galvanized, bright galvanized, plain steel, coated steel and brass bolts, nuts, washers and screws. Each type of fastener is suitable for certain applications, but not all are ideal for outdoor furniture applications.

In fact, choosing the wrong fasteners can greatly shorten the lifespan of your furniture, contribute to rot of wood furniture, cause unsightly staining, and even make your furniture unsafe to use.

One thing that needs to be noted right up front is, do not ever use unprotected steel fasteners for outdoor furniture, they will rust very quickly, and the steel will react with the tannic acid in the wood causing streaks and staining. The tannic acid actually speeds up the corrosion of the fasteners. Have you ever seen a wooden fence with black streaks running down the boards from the nails? This fence was installed with the wrong type of fasteners. The same thing will happen to your furniture. Even worse, as the fasteners rust, they will speed up the decay process of the wood around the rusted fasteners, ruining your furniture and making it potentially unsafe to use.

Hot Dipped Galvanized

Screws and bolts treated by hot dipped galvanizing are specifically designed for use outdoors. Electroplated galvanized or bright galvanized fasteners will very well not hold up as well as the hot dipped galvanized hardware. Zinc is used as a coating in both methods, and acts as a barrier against the elements and the tannic acids in the wood.

I strongly recommend only using screws or bolts in the construction of outdoor furniture, however. The galvanized finish on nails, either electroplated or hot dipped, can easily become damaged while hammering them in, exposing the nail head to the elements and allowing them to begin rusting quickly.

Adequate care must be taken when installing galvanized screws. Drill pilot holes in hardwoods, and be sure to use a bit that is not worn and intolerable to skipping in the screw head. For whatever reason, the galvanized screws seem to not be as well tempered as other steel fasteners, and are more likely to either snap off or have the heads strip out while installing them. Due to the permission required for the hot dipped coating, galvanized bolts do not have as tight of tolerance on the threads, and are more likely to strip if over tightened.

Hot dipped galvanized fasteners are a fine choice for many outdoor furniture applications, including Adirondack Chairs, but are not the best choice for use in woods, such as teak.

Stainless steel

Stainless steel is the best choice for use in woods with higher levels of tannic acid, such as teak. Stainless steel is an alloy or blend of steel, nickel and chrome. The ratio of the other metals with the steel determine the weather and corrosion resistance of stainless steel. Because the steel is mixed with other softer metals, the stainless steel is not as strong, so predrilling of screw holes is highly recommended in all applications, and essential in hardwoods such as teak and mahogany. The added corrosion resistance more than outweighs any shortcomings that the metal may have, especially in outdoor furniture applications.

While stainless steel fasteners are the most rust resistant, they are also the most expensive of the options we are discussing. However, using stainless steel fasteners will add years of life to your furniture. In the respect, they are an investment that will pay out for years to come.

Brass

I have seen brass used in some commercially produced outdoor furniture, but do not recommend it. While brass does not form red rust, and is well suited for many wet applications such as toilets and sinks, it does tarnish and corrode. It is also very susceptible to the tannic acids in wood, which will cause it to fail more quickly. Brass screws in particular Do not have sufficient strength for outdoor furniture applications.

Outdoor or deck screws

In the past several years a number of manufacturers have introduced outdoor fastening products specifically marketed for deck building. These will typically be green, gray, tan or brown. These screws are either ceramic or plastic coated to delay the metal reacting with the wood acids. The specific coating methods are proprietary to each manufacturer, and can be a combination of electroplated galvanizing and plastic, or a baked on ceramic.

I have used these fasteners in furniture applications and they perform just fine. Unfortunately, I have not come across bolts with this type of finish. The brand of screw I used was Deck Mate, and they were available in tan and brown, so that the color can be selected to better match the wood being used. These screws are ceramic covered, and the manufacturer provided a coated bit for installation, which was designed to not damage the ceramic coating at the screw head. If you choose this type of fastener, be sure to compare the cost with stainless steel, as the price will vary. If the stainless steel is reasonably comparable in cost, it would be the recommended fastener.

Always be sure to read the manufacturers specifications on the box to be sure that the screws are suitable for your application.

Other Considerations

If you are building furniture that will be located on a covered porch or patio where it will be protected from the elements, the concern will be the interaction between the wood and the fasteners, much more so than the weather. Furniture that will be exposed to the elements all year, such as a garden bench, or an adirondack chair in the corner of your garden, will have to be constructed with much more care and concern to ensure that they hold up more than just one or Two winters.

Additional considerations must be made beyond just the choice of what type of fastener to use, though this is very important. For example, fasteners should not be located where water where collect and sit on the fasteners for an extended period of time. The screws that attach the seat slats to an Adirondack chair are a prime example- typically these screws will be countersunk below the surface of the wood. This will allow water to collect in the screw holes, shortening the life span of all but stainless steel fasteners, and prolonging the exposure of the wood to water, which will increase the rate of decay. In applications where the furniture will be exposed to the elements year round the screw heads should be driven flush with the surface of the surrounding wood.

Construction and design of the furniture are also important considerations. Are the horizontal surfaces of the furniture constructed in such a way that will allow them to shed water, rather than collect it? Think of a picnic table with a slatted or board top. The gaps between the boards allow water a way to run off the top and not pool up.

Conclusion

Stainless steel is usually the best choice for outdoor furniture applications, although the cost may be prohibitive for some. There are other less expensive fastener options available that will perform acceptably. Do not use unprotected steel fasteners for outdoor furniture applications under any circumstances. Know where and how you intend to use your furniture and design it for the conditions it will be subjected to.

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Wide Area Network (WAN)

Types and Characteristics of WANs

What is a WAN?

There are two prevailing definitions of a Wide Area Network (WAN). The book definition of a WAN is a network that spans large geographical locations, typically to interconnect multiple Local Area Networks (LANs). The practical definition of a WAN is a network that traverses a public network or commercial carrier, using one of several WAN technologies

What are its Main Components?

The main components for a WAN are routers, switches and modems. These components are described below in the hardware section.

CPE – Devices on the subscriber contracts are called customer premises equipment (CPE).
The subscriber owns the CPE or leases the CPE from the service provider. A copper or fiber cable connects the CPE to the service provider's nearest exchange or central office. This cabling is often called the local loop, or "last-mile".

DTE / DCE – Devices that put data on the local loop are called data circuit-terminating equipment, or data communications equipment (DCE). The customer devices that pass the data to the DCE are called data terminal equipment (DTE). The DCE primarily provides an interface for the DTE into the communication link on the WAN cloud.

Hardware

In a WAN you will need various types of hardware components for it to function. The typical items of hardware that you will need in a WAN are:

Router – An electronic device that connects a local area network (LAN) to a wide area network (WAN) and handles the task of routing messages between the two networks. Operates at layer 3, and makes decisions using IP addresses.

Switch – A switch is a network device that selects a path or circuit for sending a unit of data to its next destination. Operates at layer 2, and uses MAC addresses to send data to correct destination.

Modem – Short for modulator / demodulator, a modem that enables a computer to communicate with other computers over telephone lines. Operates at layer 1, where signals are converted from digital to analogue and vice versa for transmission and receiving.

Wan Standards

WANs operate within the OSI model using layer 1 and layer 2 levels. The data link layer and the physical layer. The physical layer protocols describe how to provide electrical, mechanical and functional connections to the services provided by the ISP. The data link layer defines how data is encapsulated for transmission to remote sites.

Encapsulation

Encapsulation is the wrapping of data in a particular protocol header. Remember that WANs operate at the physical layer and the data link layer of the osi model and that higher layer protocols such as IP are encapsulated when sent across the WAN link. Serial interfaces support a wide range of WAN encapsulation types, which must be manually specified. These types include SDLC, PPP, Frame delay etc. Regardless of WAN encapsulation used it must be identical on both sides of the point to point link.

Packet and Circuit Switching

Circuit switching and packet switching are both used in high-capacity networks.
The majority of switched networks today get data across the network
Through packet switching.

Circuit-switching is more reliable than packet-switching. Circuit switching is old and expensive, packet switching is more modern.

General Routing Issues

What is a Routing Protocol?

A routing protocol is a protocol that specifies how routers communicate and exchange information on a network. Each router has prior knowledge of its immediate neighbors and knows the structure of the network topology. The routers know this because the routing protocol shares this information.

Protocol

RIP (Routing Information Protocol) was one of the most commonly used protocols on internal networks. Routers use RIP to dynamically adapt changes to the network connections and communicate information about which networks routers can reach and the distance between them. RIP is sometimes said to stand for Rest in Pieces in reference to the reputation that RIP has for breaking unexpectedly and rendering a network unable to function.

Routing Algorithms

Distance Vector

This type of routing protocol requires that each router simply inform its neighbors of its routing table. The distance vector protocol is also known as the bellman-ford algorithm.

Link State

This type of routing protocol requires that each router maintain a partial map of the network. The link state algorithm is also know as Dijkstra's algorithm.

IGRP

IGRP is a type of distance vector routing protocol invented by cisco used to exchange routing data in a autonomous system. Distance vector protocols measure distances and compare routes. Routers that use distance vector must send all or a portion of their routing table in a routing update message at regular intervals to each neighbor router.

Addressing and Routing

What does routing mean?

Routing is the process of deciding how to move packets from one network to another.
The directions also known as routes can be learned by a router using a routing protocol then the information is passed from router to router along the route of the destination.

IP Address's

Every machine connected to the internet is assigned an IP address. An example of an IP address would be 192.168.0.1. IP addresses are displayed in decimal format to make it easier for humans to understand but computers communicate in binary form. The four numbers that separate an IP address are called Octets. Each position consists of eight bits. When added to together you get 32 ​​bit address. The purpose of each octet in an IP address is to create classes of IP addresses that can be assigned within a network. There are three main classes that we deal with Class A, B and C. The octets of an IP address are split into two parts Network and Host. In a class A address the first octet is the network portion, this determinates which network the computer belongs to, the last octets of the address are the hosts that belong to the network.

Sub netting

Sub netting allows you to create multiple networks within a class A, B or C address. The subnet address is the address used by your LAN. In a Class C network address you would have a subnet mask of 255.255.255.0. A subnet mask identifies which portion is network and which is host. For example 192.168.6.15 the first octet three octets are the Network address and the last octet being the host (Workstation). It is important to subnet a network because gateways need to forward packets to other LANS. By giving each NIC on the gateway an IP address and a Subnet mask it allows the gateways to route packets from LAN to LAN. Once the packet arrives at its destination, the gateway then uses the bits of the subnet portion of the IP address to decide which LAN to send the packets.

Circuit Switched Leased Lines

A circuit switched network is one that establishes a dedicated circuit (or channel) between nodes and terminals before the users may communicate. Here are some terminologies associated with a Circuit switched network.

Frame relay is a telecommunication service designed for cost-efficient data transmission between local area networks (LANs)

Basic rate interference is a service used by small business for internet connectivity. An ISDN BRI provides two 64 Kbps digital channels to the user.
Primary rate interface (PRI) is a telecommunications standard for carrying voice and data transmissions between two locations
All data and voice channels are ISDN and operate at 64kbit / s

Packet Switching

Http://www.raduniversity.com/networks/2004/PacketSwitching/main.htm – _Toc80455261

Packet switching refers to protocols in which messages are broken up into small packets before they are sent. Each packet is then transmitted over the Internet. At the destination the packages are reassembled into the original message. Packet switching main difference from Circuit Switching is that that the communication lines are not dedicated to passing messages from the source to the destination. In Packet Switching, different messages can use the same network resources within the same time period.

Http://en.wikipedia.org/wiki/Asynchronous_Transfer_Mode

Asynchronous Transfer Mode (ATM) is a cell relay, packet switching network and protocolwhich encodes data into small fixed-sized cells.

ISDN is used to carry voice, data, video and images across a telephone network. ISDN stands for integrated services Digital Network. Isdn also provides users with a 128kbps bandwidth. This is done through frame relay. Frame relay complements and provides a service between ISDN, which offers bandwidth at 128 Kbps and Asynchronous Transfer Mode which operates in somewhat similar fashion to frame relay but at speeds from 155.520 Mbps or 622.080 Mbps. Frame relay is based on the older X.25 packet switching technology and is used to transmit analogue signals such as telephone conversations.

PSDN stands for packet switched data network and is a data communication network. Packet switched networks do not establish a physical communication signal like the public telephone circuit (circuit switched network) Packets are sent on a fixed length basis and assigned with a source and a destination address. The packages then explicitly on the routers to read the address and route the packets through the network.

Mobile and Broadband Services

Digital Subscriber Line (DSL) is mainly used to bring high bandwidth connections to homes and small business's over a copper wire telephone line. This is can only be achieved if you stay within the range of the telephone exchange. DSL offers download rates of up to 6mbps allowing continuous transmission of video, audio and 3D effects. DSL is set to replace ISDN and compete with the cable modem in providing multimedia to homes. DSL works by connecting your telephone line to the telephone office over copper wires that are twisted together.

Asymmetric Digital Subscribers Line is most commonly used for home users. It provides a high download speed but a lower upload speed. Using ADSL, up to 6.1 megabits per second of data can be sent downstream and up to 640 Kbps upstream.

Http://en.wikipedia.org/wiki/Symmetric_Digital_Subscriber_Line

Symmetric Digital Subscriber Line is a digital subcriber line which runs over one pair of copper wires. The main difference between ADSL and SDSL is the difference in upload and download speeds. SDSL allows the same upstream data rate and downstream data rate as ADSL upstream can be very slow.

[Http://searchnetworking.techtarget.com/sDefinition/0],,sid7_gci558545,00.html

HDSL High bit-rate Digital Subscriber Line, one of the earliest forms of DSL, is used for wideband digital transmission within a corporate site and between the telephone company and a customer. The main characteristic of HDSL is that that provides equal bandwidth in both directions.

IDSL is a system in which data is transmitted at 128 Kbps on a regular copper telephone line from a user to a destination using digital transmission.

The Local Loop enables operators to connect directly to the consumer via copper local loops and then add their own equipment to offer broadband and other services. This process involves operators accessing local exchange buildings to connect to a network of copper lines which connect them to homes and businesses. BT is an Example of a Local Exchange. The local loop connecting the telephone exchange to most subscribers is capable of carrying frequencies well beyond the 3.4 kHz upper limit.

Benefits of using DSL

DSL can provide a virtual instantaneous transmission of voice, data and video over ordinary copper phone lines. A DSL connection can eliminate delays while waiting to download information and graphics from the Internet. It provides users with a cost effective high speed Internet connection. Another benefit is that a DSL connection is always on-line (like a LAN connection) with no waiting time for dialing or connecting.

There are now more than 10 million broadband connections in the UK. By December 2005 there were 9.792 million broadband connections in the UK and the average broadband take up rate during the three months to December was more than 70,000 per week.

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