TYPES OF INTERNET SERVICE PROVIDER ACCOUNTS
There are many types of connections USER can get on the internet depending on the type of use and the amount of resources (money) available. The different types of connections, their advantages and limitations have been discussed below:
No matter what type of connection you go in for, it should be reliable, fast, easily available, and economical. There is no such thins as a free connection to the Internet. Someone, somewhere has to pay for the equipment, software, telephone lines, and electricity.
Basically there are four types of connections to the Internet:
1. Dial-up Connection
2. ISDN Connection
3. Leased Line Connection
4. Cable Modem
5. DSL
6. Broadband
7. V-SAT
The most popular type of connection for an individual is the broadband connection as it is easily available and economical.
1. Dial-Up Connection
As the name suggests, dial-up link means you have to dial into a modem over a telephone line before you can get connected to the internet. A modem (modulator demodulator) is a device which converts digital signals emitting from the computer into analog signals so that the data is easily transmitted over analog telephone lines. At the receiving end, there is another modem which converts these transmitted analog signals back to the digital form which are received by the target computer.
For this type of connection you require:
A computer whose configuration could be 80486 but the best is Pentium-IV or above. Communication software, like dialer which the Internet connection provider will give and a telephone line.
A modem (optimal speed is 36.6 Kbps). These days we use modems of speeds up to 56 Kbps. Software like a browser, e-mail programme, FTP software, Newsgroup reader, Eudora, Outlook Express, etc. Outlook Express is one of the software which helps to read news and mail offline once they have been collected online.
There are 3 major ways by which you can get linked to the Internet using a dial-up connection, namely;
A. Host terminal connection
B. Individual computer
C. Dial-Up or on demand through the LAN.
A. Host Terminal Connection (Terminal Emulation)
In case of host terminal connection, a PC is connected to some Internet host via modem and a terminal emulation programme is run. Your terminal now acts like a vt-100 terminal . In other words, you are connected to a large computer which is connected to the Internet. Thus if want to download a file, the file is downloaded to the host and not your computer. To download a file from their host to your computer you need to have some specific software. In this type of connection you can download only text but not graphics. Hence, a host terminal connection is also referred to as a shell account. This account is best suitable for :
1. Students whose budget is low and their requirement is limited to text.
2. Users who connect via Telnet programmes.
3. Users whose frequency to use the Internet is low.
4. Users who want to use the Internet to access the network of their workplace from their home place (personal account). Such users could connect via Telnet.
5. Jobs where multi-tasking is not required. This connection permits only one task at a time, e.g., the user cannot read the news as well as download a file.
This type of a connection offers three different types of accounts depending on your distance from the ISP and the nature of work for which you want the connection.
1. Local dial.
2. Use of public data networks.
3. Restricted access.
1. Local Dial: Local dial is the cheapest type and is only possible if the host is at a local telephone call distance away.
2. Public Data Network: If the host is not in the vicinity, then long distance calls have to be made over public data networks. If the speed of such networks is slow then data transmission speed will also be slow and so the connection will prove to be more expensive.
3. Restricted Access Account: Suppose you want to access only E-mail or newsgroups. In such situations, restricted access account is best for you. There are certain sites which provide inexpensive E-mail accounts, local bulletin board services, etc. you just have to registered pay only for the services you want to use.
B. Individual Computer
Here your computer can work as an Internet Host, i.e., direct downloading of files and mails can be done when connected to the internet. This kind of link is a little more costly than the host terminal connection as you have to pay a monthly fees to the service provider or sometimes even a flat charge for a fixed period of time. Here you can have one or both the following account ;
1. Serial Line Internet Protocol (SLIP)
2. Point to Point Protocol (PPP)
1. Serial Line Internet Protocol (SLIP) . In case of SLIP data is sent in packets under speeds of 9600 bps on telephone lines using data compression protocols.
2. Point-to-Point Protocol (PPP). In case of PPP data is sent over telephone lines via modem. Double checking is done at the destination to see if data packets have arrived intact. This is better than SLIP as it allows authentification of users. These days PPP connections are more common. Again, speed of data transfer in PPP is faster than in SLIP.
This type of connection is good for people who:
1. Use Graphics.
2. Download files often.
3. Use direct e-mail or any other online service.
4. Use Internet regularly though for limited hours.
The limitations are few, such as , people may not be able to access the Internet easily if the disk space is limited or if the line is slow (i.e., speeds below 28.8 Kbps will not be accessible by other people).
C. Dial-Up or On-Demand through the LAN
In this case there is a dial up link from the LAN to which you are connected to. This type of connection is favourable for small business houses and educational institutes. Here the server, on demand, dials up for a connection and once the connection is established everybody logged on to the LAN can access the Internet. In such a situation if there is any file downloaded from the Internet then like any other file, this file will be accessible to all LAN clients. The only problem here is that the more the number of users logged onto the LAN and working on the Internet, the slower will be the Internet connect6ion. However, this is successful if you have a very fast server software along with a very fast line. Again extra software like proxy servers are also required to serve the needs of various individual LAN users with one Internet connection.
2. Integrated Services Digital Network Connection (ISDN) This is a very high speed connection to the Internet over normal telephone line. It combines both voice and digital information in a single medium, making it possible to provide the customers with digital as well as voice connections. In ISDN connection, the information which is sent from your computer to the Internet is digital. Here we do not use a normal modem. As no conversion from analog to digital or vice versa is required, so we use an ISDN modem which is merely a terminal adapter. Another differences lies in the fact that the ISDN lines, in order to work, require power from outside. When there is a power shutdown, ISDN lines will not work. ISDN service has many variations but we follow Basic Rate Interface (BRI) Service. Here the ISDN line is divided into three logical channels, namely :
1. Two 64 Kbps B (bearer) channels.
2. One 16 Kbps D (Data) channel.
Thus ISDN is commonly referred to as 2B+D.
Over bearer channels you can send data. If only data is sent then it could be sent at a speed of 64+64=128 Kbps but if both data and voice is to travel then one B channel is dedicated to voice and the other to data. The data or D channel is used to send signaling information for routing data which is being sent over B channels. Those telephone companies which do not have the ability to use D channels remove 8 Kbps from each B channel. Therefore, only 56 Kbps of data can go over each of these B channels.
Apart from voice, many value added services are also being offered like:
1. Telephones will soon have the facility to display name, address, and telephone number of the caller while the telephone rings.
2. When the telephone gets connected to the computer, the caller’s database record is displayed on the computer.
3. Call forwarding facility
4. Remote electricity meter reading services.
5. Smoke alarms that automatically call up the hospital, fire station or police station.
Advantages of using ISDN:
1. Allows high speed access, i.e., 128 Kbps.
2. No special laying down of wires. The existing copper telephone cables work fine.
3. Can be used for voice, data, graphics, full motion video as data transfer speed is high.
The only disadvantage of using ISDN is that it proves to be an expensive affair as special equipment is required for it and the tariff is also high.
3. Leased Line Connection (Dedicated Connection)
As the name suggests, a leased line connection is a permanent connection laid down between you and a modem. As it is permanently lined, you have a 24 hour access to the Internet, seven days in a week. A leased line connection is very useful especially when frequent information has to be accessed from the Internet and also when the volume of data transfer is high. It is also useful if the Internet is to be used for more than 12 hours a
day.
This type of connection is the most reliable and has high speed. The only issue behind this connection is its cost.
The cost includes :
1. One time installation (laying down of physical line upto your site).
2. Yearly/periodically maintenance charge.
3. Annual tariff.
4. The necessary one time hardware, software and set up charges.
4. Cable Modem In case of cable modem the Internet can be accessed through the normal coaxial television cables with the help of cable modems. Speed of cable modems is 10 to 100 times faster than normal dial-up connection modems. The only catch is that the local cable operator should have the capability to access the Internet over cable TV wires and that cable modems are slightly more expensive than normal modems. One advantage of cable modem connection is that you need not have a telephone line if you want this type of connection to the Internet.
Before giving approximate tariff rates for the different types of connections, let us discuss the role of Videsh Sanchar Nigam Limited (VSNL). VSNL is the gateway to Internet in India. It is also an Internet Service Provider (ISP) so that the user can acquire a connection from it. Until recently, VSNL was the only gateway of the Internet in India but now we have another private gateway, namely, Now Convergence. This organization also has some very good offers like faster downloads. Let us now discuss the role of an
ISP.
5. DSL
DSL or Digital Subscriber Line service is provided through the existing telephone line, but it works differently than regular analog modem dial-up access. DSL operates over normal telephone lines and it can be used simultaneously with the telephone. DSL can increase the connection speed by as much as ten-fold from a standard dial-up modem.
6. Broadband
This type of access is good for remote locations, where ISDN, cable or DSL are not available. It gives a decent download speed, but to upload the data, the user still needs a regular analog modem to dial in, via a telephone line. Satellite connection can be either a two way service or a one way service. In case of two-way satellite service, the data is transmitted via satellite to a dish antenna at the user’s house. In one-way system, the user needs a conventional modem and a telephone link to an ISP. Satellite connection is expensive but sometimes is the only fast option for the people who are beyond the service area of cable and DSL providers.
7. Very Small Aperture Terminals (VSATs) The two ground stations that communicate with one another via the satellite need not be the same size or transmit data with the same amount of power. Many satellite networks use a large number of small dishes, called VSATs (very small aperture terminals), for the outlying nodes and one central hub with a big dish that can transmit very powerful signals and is very sensitive to incoming ones. This system minimizes the cost of the majority of the ground stations at the expense of maintaining one big one, which can be shared by several users, However, this approach can cause additional delays, because the VSATs aren’t powerful enough to talk to one another directly through the satellite; messages must pass through the hub and make two trips into space before reaching their final destination, incurring a double delay.
VSATs are typically used by organizations, such as oil companies, that require data or voice communications between sites distributed over a wide geographical area. Terrestrial links are economical over short distances; their cost climbs quickly as the distance between locations increases. In addition, terrestrial data and voice links, while readily available in cities, are often difficult, if not impossible, to obtain in smaller urban 'and remote local areas using these links.
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1. What are the different types of Internet Service Provider (ISP) accounts? |
2. What are the advantages of broadband ISP accounts over dial-up? |
3. Can I switch my dial-up ISP account to a broadband account? |
4. What are the benefits of wireless ISP accounts? |
5. What is a dedicated ISP account and who typically uses it? |
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