Mirror Magazine

Mirror Magazine

Techno Page - Email: technopage_lk@yahoo.com

Dial-up misery for Internet users
It has been most heartening to see Sri Lanka taking strides towards development and expansion in the telecommunications industry. It seems that the truth has finally dawned, that it is impossible to move forward as a considerable economic force in the region without breaking free of the antique telecommunications services that are currently in use.

As we move forward, it is important that we strive to keep pace with the latest advancements in communication technology which is evolving as fast as our imagination.

Yet one fears whether Internet related services have been neglected altogether, as the average home Internet connection has not been able to break the 56k dial-up modem barrier for at least the past four years. ADSL Internet connections have been tested for well over a year, but nobody knows why they have not yet been offered in the open market. It is time for broad band Internet to come into Sri Lanka and end the 'dial-up' misery.

Are you annoyed with the connection speeds (and, of course, disconnection speeds) of dial-up access? Write in to technopage_lk@yahoo.com and be heard.

Understanding IP addressing
Every computer that communicates over the Internet is assigned an IP address that uniquely identifies the device and distinguishes it from other computers on the Internet. An IP address consists of 32 bits, often shown as 4 octets of numbers from 0 - 255 represented in decimal form instead of binary form. For example, the IP address 168.212.226.204 in binary form is 10101000.11010100.11100010.11001100.

But it is easier for us to remember decimals than it is to remember binary numbers, so we use decimals to represent the IP addresses when describing them. However, the binary number is important because that will determine which class of network the IP address belongs to. An IP address consists of two parts, one identifying the network and the other identifying the node or host. The Class of the address determines which part belongs to the network address and which part belongs to the node address. All nodes on a given network share the same network prefix but must have a unique host number.

Class A Network binary address starts with 0, therefore the decimal number can be anywhere from 1 to 126. The first 8 bits (the first octet) identify the network and the remaining 24 bits indicate the host within the network. An example of a Class A IP address is 102.168.212.226, where '102' identifies the network and '168.212.226' identifies the host on that network.

Class B Network binary addresses start with 10, therefore, the decimal number can be anywhere from 128 to 191. (The number 127 is reserved for loopback and is used for internal testing on the local machine.) The first 16 bits (the first two octets) identify the network and the remaining 16 bits indicate the host within the network. An example of a Class B IP address is 168.212.226.204 where '168.212' identifies the network and '226.204' identifies the host on that network.

Class C Network binary addresses start with 110, therefore, the decimal number can be anywhere from 192 to 223. The first 24 bits (the first three octets) identify the network and the remaining 8 bits indicate the host within the network. An example of a Class C IP address is 200.168.212.226 where '200.168.212' identifies the network and '226' identifies the host on that network.

Class D Network binary addresses start with 1110, therefore, the decimal number can be anywhere from 224 to 239. Class D networks are used to support multicasting.

Class E Network binary addresses start with 1111, therefore, the decimal number can be anywhere from 240 to 255. Class E networks are used for experimentation. They have never been documented or utilised in a standard way.
Sent in by
Indika Samarasinghe

Internet speed record
Scientists at the Stanford Linear Accelerator Centre used fibre-optic cables to transfer 6.7 gigabytes of data (the equivalent of two DVD movies) across 6,800 miles in less than a minute. The data was sent via fibre-optic cables from California, to Chicago, Illinois.

From Chicago, the data was relayed to Geneva, Switzerland and from there on to Amsterdam, Netherlands. The information travelled the 6,800 miles in less than a minute.

The team was able to transfer uncompressed data at 923 megabits per second for 58 seconds from Sunnyvale, California to Amsterdam, Netherlands. That's about 3,500 times faster than a typical Internet broadband connection.

On average, the amount of information that can be transferred over the Internet has doubled every year since 1984. That trend is expected to continue. Internet users and businesses could benefit from these findings.

Scientists were able to get 93 per cent efficiency out of their record-setting connection because they didn't have to share bandwidth. Even if they could transfer vast amounts of data tomorrow at reasonable prices, present-day computers are unable to handle such loads.

It is believed that the findings will hopefully help researchers develop a clearer plan for faster online technologies for the future.
WebOnline.com

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