INTERNET CONNECTION AND CONFIGURATION

INTERNET CONNECTION AND CONFIGURATION

Network Hub
Broadband providers like cable modem and DSL companies always suggest getting multiple IP address’ to connect multiple computers to their modem. This may work fine for surfing and email, but can be a huge headache and security risk for sharing files and printers. Of course, the broadband providers do not tell you this because they usually get to charge you extra money for each computer this way. This article will explain why this is a bad idea.



Most broadband companies will help you get multiple computers on the Internet by selling you additional IP address. You will need a hub or a switch between your cable modem and computers but little else is needed. Both computers can get to the Internet, but the whole Internet can get to both of your computers too!



When file sharing is enabled, Microsoft windows ‘broadcasts’ the fact that you have files and printers to share. When ‘bound’ to TCP/IP, this information is available to the whole world! Hackers are always scanning the Internet for Microsoft file and print shares on the Internet. You can enable a password on each of your shares, but it is VERY easy to forget to do this.

Worse still, if your computers were given IP address’ by your ISP that are on different logical networks, or subnets, then your computers will be unable to easily see each other in your network neighborhood. If you are on a cable modem, your neighbors might be able to see your computers easier than you can! ARGH!

Some web sites say that the best way to deal with this problem is to install NetBEUI to share files and printers. The problem with this is two fold. 1) your neighbors may STILL be able to see your file and print shares and 2) your file copy traffic is not only sent between your computers, it is sent out over the broadband modem! Copying files can become VERY slow and unreliable. Often large files become corrupted or fail to copy with a network like this.



The Solution:
The solution is to separate your Internet traffic from your LAN (file sharing) traffic. To do this, a special networking device or software can be placed between your computers and the Internet. The devices are called broadband routers or Internet gateways. Programs can be loaded on one of your computer to do this but require two network cards in the computer that has the sharing software running.

Newer Microsoft operating systems have a program called ICS that can do this for you or more robust solutions can be purchased from various software vendors.


Broadband routers are a better solution if you want to be able to plug in a device and never have to think about it again. Broadband routers have been expensive in the past but now are well under $100 for a basic model.



A broadband router will keep your computers from broadcasting their file sharing traffic across the Internet. In addition, attempts by hackers to access your computers are stopped by a broadband router. Lastly, broadband routers can share your single Internet connection with all the computers in your house without having to pay your broadband provider extra money for each computer!

Server
Definition: A network server is a computer designed to process requests and deliver data to other (client) computers over a local network or the Internet.
Network servers typically are configured with additional processing, memory and storage capacity to handle the load of servicing clients. Common types of network servers include:
• Web servers
• proxy servers
• FTP servers
• online game servers
Numerous systems use this client / server networking model including Web sites and email services. An alternative model, peer-to-peer networking enables all computers to act as either a server or client as needed.

Network switch

A network switch is a device that provides a switching function in a data communications network. Data communication in a computer network involves the exchange of data between two or more entities interconnected by communication links and subnetworks. A network switch is an intermediate station which interconnects the communication links and subnetworks to enable transmission of data between the end stations. Switching involves transferring information, such as digital data packets or frames, among entities of the network. A switch functions as an interchange and provides path switching for data being transported over a network. Typically, a switch supports one network protocol (e.g. Ethernet), meaning that the switch manages data in a particular format. Switched local area networks use a network switch for supplying data frames between network stations or other network nodes (such as routers or gateways), where each network node is connected to the network switch by a media. A network switch for routing packets between network buses includes a set of input switch ports for receiving packets arriving on the network buses, a set of output switch ports for forwarding packets outward on the network buses, and a switch fabric for routing packets between the input and output switch ports. Each input switch port includes a memory for storing packets arriving on a network until the switch fabric can forward them to an output switch port. The input port may convert each packet arriving on a network bus to a sequence of cells of uniform size which can be efficiently stored in uniformly-sized buffer memory storage locations until the input port can forward them in proper sequential order through the switch fabric to one of the switch's output ports. Each output switch port may also include a memory for storing packets it receives via the switch fabric until the port can forward them outward on a network bus. Each output switch port stores each cell sequence arriving from an input port in its own buffer memory. The output port later reassembles them into the packet from which they were derived, then forwards the packet outward on an another network bus.

VSAT
VSAT is an abbreviation for a Very Small Aperture Terminal. It is basically a two-way satellite ground station with a less than 3 meters tall (most of them are about 0.75 m to 1.2 m tall) dish antenna stationed. The transmission rates of VSATs are usually from very low and up to 4 Mbit/s. These VSATs' primary job is accessing the satellites in the geosynchronous orbit and relaying data from terminals in earth to other terminals and hubs. They will often transmit narrowband data, such as the transactions of credit cards, polling, RFID (radio frequency identification) data, and SCADA (Supervisory Control and Data Acquisition), or broadband data, such as satellite Internet, VoIP, and videos. However, the VSAT technology is also used for various types of communications.
Equatorial Communications first used the spread spectrum technology to commercialize the VSATs, which were at the time C band (6 GHz) receive only systems. This commercialization led to over 30,000 sales of the 60 cm antenna systems in the early 1980s. Equatorial Communications sold about 10,000 more units from 1984 to 1985 by developing a C band (4 and 6 GHz) two way system with 1 m x 0.5 m dimensions.
In 1985, the current world's most used VSATs, the Ku band (12 to 14 GHz) was co-developed by Schlumberger Oilfield Research and Hughes Aerospace. It is primarily used to provide portable network connection for exploration units, particularly doing oil field drilling.

NETWORK CABLE
Network cable is used to connect and transfer data between computers and a network. There are different types of network cable, and the appropriate type to use will depend on the structure and topology of your network. The most commonly used types of network cable are the twisted pair, coaxial, Ethernet cross over, and fiber optic.
The unshielded twisted pair (UTP) cable is used in many Ethernet networks. It has four pairs of wires that are housed inside of the lining of the cable. Each pair is twisted into several additional twists to prevent interference from other devices on the network. The structure of this type of cable increases its reliability and helps minimize network failures.
Coaxial cable, or coax, is another common type of network cable. It has a copper conductor in its center and a plastic coating serves as an insulator between the center conductor and a metal shield. The cable is then covered with a coating. The coating may be think or thick — the thicker coating which less pliable provides extra protection.
Ethernet crossover cable is used to connect a computer network made up of two or more computers. This type of network cable eliminates the need for network switches or routers. The cable also allows the computers to be connected using their network adaptors, such as the network interface card (NIC).
Fiber optic network cables are used for networks that span large distances. As a result, this type of cabling has several layers of protective coating. It also transmits light as opposed to electrical signals like other cables. This makes it an ideal cable for network environments that are exposed to large amounts of electrical interference. It also transmits information at high speeds and is therefore used in large network environments like those used by big businesses.
As wireless networks become more and more popular, network cable is becoming less necessary. Still, many systems, especially large scale systems, continue to rely on network cables.

MODEM,
Modem, short for modulator-demodulator is an electronic device that converts a computer’s digital signals into specific frequencies to travel over telephone or cable television lines. At the destination, the receiving modem demodulates the frequencies back into digital data. Computers use modems to communicate with one another over a network.
The modem has significantly evolved since the 1970s when the 300 baud modem was used for connecting computers to bulletin board systems (BBSs). With this type of modem each bit, represented digitally by a 1 or 0, was transmitted as a specific tone. The receiving modem responded with its own dedicated frequencies so that the modems could “talk at the same time.” The technical term for this type of modem is asynchronous.
While the 300 baud modem could transmit about 30-characters per second, fast enough for text-based BBSs, people were soon sharing programs and graphics. This required faster modems, and the modem went through many incarnations in rapid succession over the following three decades. By 1998 the standard dial-up modem maxed out its transmission range at 56 kilobits per second. While many tens of times faster than the 300-baud modem, far greater speeds could yet be reached with an Asymmetric Digital Subscriber Line (ADSL) modem.
The designation asymmetric simply means that the modem is faster at downloading (getting data), than uploading (sending data). The ADSL modem has significant, immediate advantages over the dial-up modem. Though it uses a standard telephone line like a dial-up modem, it does not tie up the line, making it possible to use the telephone while cruising the Internet. ADSL service is an “always on” connection, unlike a dial-up modem that cannot be left connected indefinitely. Finally, the ADSL modem is far faster than a dial-up modem.
The ADSL modem can accommodate a telephone conversation because of available bandwidth on the dedicated copper wire, which runs from households and businesses to the telephone company (Telco). A parallel can be made to a multi-lane freeway with several lanes open for additional traffic. The ADSL modem uses the additional lanes (higher frequencies) without interfering with existing voice traffic. An ADSL modem requires ADSL service through an Internet Service Provider (ISP). This type of modem will not work with a dial-up account.
Some businesses require as much bandwidth going upstream as downstream. This means they need to upload large files or programs to the Internet, as well as download large files. For equal bandwidth in both directions, one would need a Symmetric DSL (SDSL) account and SDSL modem. The SDSL modem uses voice traffic lanes to expand bandwidth, and therefore a conversation is not possible when the SDSL modem is connected. For this reason most businesses use a dedicated phone line with an SDSL modem.
Yet another type of modem uses cable TV wiring rather then the phone line to provide Internet connectivity. A cable modem requires service from a cable TV provider for Internet connectivity. The cable modem works on the same principle as the DSL modem, in that digital data is transferred across wires using frequencies that are translated back into digital data. Frequencies used for data traffic do not interfere with existing TV traffic.
A less common modem is a satellite modem, or satmodem. The satellite modem converts digital data into radio waves to communicate with a satellite dish. This not only involves a built-in latency factor in most cases, but the service is more expensive than more conventional types of Internet connectivity. A satellite modem can be an option, however, for businesses or enthusiasts in rural areas that do not yet have DSL or cable service offerings.
While most DSL and cable providers offer a modem with Internet service, the subscriber can also opt to provide his or her own modem. Often the Internet provider will make a list of compatible modems available, though these lists are rarely exhaustive. Online manuals for modems and technical specifications will also commonly list which Internet Service Providers the modem supports.
Client (computing)
A client is an application or system that accesses a remote service on another computer system, known as a server, by way of a network.[1] The term was first applied to devices that were not capable of running their own stand-alone programs, but could interact with remote computers via a network. These dumb terminals were clients of the time-sharing mainframe computer.
The client-server model is still used today on the Internet, where a user may connect to a service operating on a remote system through the Internet protocol suite. Web browsers are clients that connect to web servers and retrieve web pages for display. Most people use e-mail clients to retrieve their e-mail from their internet service provider's mail storage servers. Online chat uses a variety of clients, which vary depending on the chat protocol being used. Game Clients usually refer to the software that is the game in only multiplayer online games for the computer.
Increasingly, existing large client applications are being switched to websites, making the browser a sort of universal client. This avoids the hassle of downloading a large piece of software onto any computer you want to use the application on. An example of this is the rise of webmail.
In personal computers and computer workstations, the difference between client and server operating system is often just a matter of marketing - the server version may contain more operating system components, allow more simultaneous logins, and may be more expensive, while the client version may contain more end-user software.
Types
Clients are generally classified as either "fat clients", "thin clients", or "hybrid clients".
Local storage Local processing
Fat Client Yes Yes
Hybrid Client No Yes
Thin Client No No
Fat
Main article: Fat client
A fat client (also known as a thick client or rich client) is a client that performs the bulk of any data processing operations itself, and does not necessarily rely on the server. The fat client is most common in the form of a personal computer, as the personal computers or laptops can operate independently. Programming environments for rich clients include Curl, Delphi, Droplets,.Net, Java, win32 and X11.
Thin
Main article: Thin client
A thin client is a minimal sort of client. Thin clients use the resources of the host computer. A thin client's job is generally just to graphically display pictures provided by an application server, which performs the bulk of any required data processing. Programming environments for thin clients include JavaScript/AJAX (client side automation), ASP, JSP, Ruby on Rails, Python's Django, PHP and other (depends on server-side backend and uses HTML pages or rich media like Flash, Flex or Silverlight on client).
Hybrid
Main article: Hybrid client
A hybrid client is a mixture of the above two client models. Similar to a fat client, it processes locally, but relies on the server for storage data. This approach offers features from both the fat client (multimedia support, high performance) and the thin client (high manageability, flexibility)..
Notes and references
1. ^ Sadoski, Darleen. http://www.sei.cmu.edu/str/descriptions/clientserver.html Client/Server Software Architectures--An Overview, Software Technology Roadmap, 1997-08-02. Retrieved on 2008-09-16.
Retrieved from "http://en.wikipedia.org/wiki/Client_(computing)"