Internet Infrastructure

     Assalamualaikum..in week 7, i just learned about internet infrastructure. In this topic i learn many things such as hierarchy of networks, internet service provider (ISP) , internet protocol and type of internet connection and access.


     What is the internet really means? Internet is the global communication network that allows almost all computers worldwide to connect and exchange information.

Hierarchy of networks

Hierarchy of networks is like from a single computer to LAN  and from LAN to ISP and from ISP to WWW. Every computer that is connected to the Internet is part of a network, even the one in our home. For example, we may use a modem and dial a local number to connect to an Internet Service Provider (ISP). At work, we may be part of a local area network (LAN), but  most likely still connect to the Internet using an ISP that certain company has contracted with. When we connect to our ISP, we become part of their network. The ISP may then connect to a larger network and become part of their network. The Internet is simply a network of networks.

Most large communications companies have their own dedicated backbones connecting various regions. In each region, the company has a Point of Presence (POP).  The POP is a place for local users to access the company's network, often through a local phone number or dedicated line. The amazing thing here is that there is no overall controlling network. Instead, there are several high-level networks connecting to each other through Network Access Points or NAPs.

Internet service provider

Internet service provider (ISP) is also known as internet access provider. It is the company that provides access to the internet.  Usually ISP provide software package, username, password and access phone number and modem. ISP are connected to one another through Network Access Points (NAPs). The example of ISP is TM.

Internet protocol

 Every machine on the Internet has a unique identifying number that is called an IP Address. The IP stands for Internet Protocol, which is the language that computers use to communicate over the Internet. A protocol is the pre-defined way that someone who wants to use a service talks with that service. The "someone" could be a person, but more often it is a computer program like a Web browser. A typical IP address looks like this: 216.27.61.137 . To make it easier for us humans to remember, IP addresses are normally expressed in decimal format as a dotted decimal number. But computers communicate in binary form like 11011000.00011011.00111101.10001001.

An IP address consist of 32 bits, often shown as 4 octets of numbers from 0-255.

So you can check your IP adress now http://whatismyipaddress.com/

Domain Name System ( DNS)

Internet services that translate domain name like www.google.com into numerical IP (internet protocol) address like 204.62.131.129).  The reason why we used DNS is because doman name in alphabetic and easily to remember instead of number. 

Hyper Text Transfer Protocol (HTTP)

HTTP defines how messages are formatted and transmitted and what actions Web servers and browsers should take in response to various command . For example, when we enter a URL in browser, this actually send an HTTP command to the web server directing it to fetch and transmit the requested page. 

Type of internet connection and access

1. Dial connection

          It used a conventional dial up modem connected to standard telephone jack with regular twisted-pair cabling. Usually used with home computers . Its advantages is inexpensive hardware and ease to set up but its disadvantage is slow connection.

     2. Cable

         Used a direct connection that usually found in office and its advantage is fast.

     3. Satellite internet access

        Satellite internet access used a direct connection. It slower and more expensive than cable internet access. It required transceiver satellite outside the home or building to receive and transmit data. It  availability is anywhere there is clear view and where a satelite dish can be mounted and received signal. Performance might degrade or stop during heavy rains or snowstorm. Example such as Astro.

    4. Fixed wireless

        It similar to satellite internet ,but it uses radio transmission tower instead of satellite tower. Its availability is only selected areas where service is available.

   5. Broadband

     Broadband is  high-speed Internet connection . Broadband transmits data digitally, which means a modem or similar device is required on your end to translate the data packages. Several different types of broadband services are available with their own advantages and disadvantages.

  6. Mobile wireless

      Virtually anywhere cellular phone service available.