Internet Infrastructure

• Infrastructure is the physical hardware used to interconnect users and computer.
• Infrastructure includes the transmission media, software used to receive, send, and manage the signals that are transmitted.
• Infrastructure refers to interconnecting software and hardware and not to computers and other devices that are interconnected.
• For some information technology users, infrastructure is viewed as everything that supports the flow and processing of information.

Internet Protocol (IP):

Defintion: The primary network protocol used on the Internet layer of the Internet Protocol Suite, developed (1970s). On the internet and many other networks. IP is often used together with the Transport Control Protocol (TCP) and referred to interchangeably as TCP/IP.

IP used to supports unique addressing for computers on a network. Almost all networks use the Internet Protocol version 4 (IPv4) standard that features IP addresses four bytes (32 bits) shown as 4octets of number from 1-225 represented in decima form instead of binary in length. Internet Protocol version 6 (IPv6) standard features addresses 16 bytes (128 bits) in length.

• IP specifies the format of packets called datagrams, and the addressing scheme. 
• Transmission Control Protocol (TCP), most networks combine IP with higher-level protocol, which establishes a virtual connection between a destination and a source.
• IP consist of two part: network and host/node of network.
• Class of address determines which part belongs to network add and which part belongs node address.

Class A Network

Binary add will start with 0 therefore decimal can be anywhere begin from 1-126.

First octet (8 bits) identify network. For other 3 identify the host.

Class B Network

Binary add will start with 10, so, decimal can be anywhere begin from 128-191.

For decimal 127 reserved for LOPBACK and used for internal testing on local machine.

For the first 2 octet (16bits) identfy network, other 2 octet should be indicate the host.

Class C Network

Binary add will start with 110, so, decimal  can be anywhere begin from 192-223.

For the first 3 octet (24 bits) identify network, other 1 should indicate the host.

Class D Network

Binary add will start with 1110 therefore decimal can be anywhere begin from 224-239.

Its used to support multiasking ( multi layers).

Class E Network

Binary add will starts with 1111 therefore decimal can be anywhere from 240-255.

Its used for experimentation.

DOMAIN NAME SYSTEM (DNS)

· DNS, Internet service that able to translates domain names into IP addresses. Domain names are alphabetic, its will easier to remember. However, Internet is really based on IP addresses. 

·Each time use a domain name, so, a DNS service must translate the name into the corresponding IP address. For example, the domain name www.example.com should be translate to 198.105.232.4.

·The DNS system has own network. If one DNS server not able to translate a particular domain name, its will asks another one, and so on, until the correct IP address is returned.

· The Domain Name System makes it possible to assign domain names to groups of Internet resources and users in a meaningful way, independent of each entity's physical location. 

·Because of this, World Wide Web (WWW) hyperlinks and Internet contact information can remain consistent and constant even if the current Internet routing arrangements change or the participant uses a mobile device.

·Internet domain names are easier to remember than IP addresses. Users take advantage of this when they recite meaningful Uniform Resource Locators (URLs) and e-mail addresses without having to know how the computer actually locates them.

·DNS also stores other types of information, such as the list of mail serversthat accept email for a given Internet domain. By providing a worldwide, distributed keyword-based redirection service, the Domain Name System is an essential component of the functionality of the Internet.

INTERNET ACCESS PROVIDER (ISP)

· An Internet service provider (ISP) is an organization that provides access to the Internet. Internet service providers can be either community-ownedand non-profit, or privately owned and for-profit.

·Access ISPs directly connect clients to the Internet using copper wires,wireless or fiber-optic connections.

·ISP, it refers to a company that provides Internet services, including personal and business access to the Internet. For a monthly fee, the service provider usually provides a software package, username, password and access phone number.

·Equipped with a modem, you can then log on to the Internet and browsethe World Wide Web and USENET, and send and receive e-mail. For broadband access you typically receive the broadband modem hardware or pay a monthly fee for this equipment that is added to your ISP account billing.

·In addition to serving individuals, ISPs also serve large companies, providing a direct connection from the company's networks to the Internet. ISPs themselves are connected to one another through Network Access Points (NAPs). ISPs may also be called IAPs (Internet Access Providers).

HTTP

·HTTP stands for HyperText Transfer Protocol. Hypertext is a multi-linear set of objects, building a network by using logical links (the so calledhyperlinks) between the nodes (e.g. text or words).

·HTTP is the protocol to exchange or transfer hypertext.

·It’s what browsers and web servers rely on for exchanging data so that you can surf the web, browse web pages, search Google, download pictures, and viewing YouTube.

·Developed by W3C and IETF in the last few years of the last century, it’s part of a bigger protocol family created to support the whole Internet, called TCP/IP. As a subset, HTTP’s responsibility is the World Wide Web or WWW.

·By HTTP definition and usage, it’s fundamentally an information exchanging procedure standard between 2 communicating parties or computers, such as the client and the server.

·While you type a URL address in the web browser, the browser will have to know the protocol to use when fetching the remote resource such as a web page or a picture at that address. Failing to do so, as we most of the time would do without the http:// part, the browser will assume HTTP by default and prepend it to the URL address.

A web address representing an access point on the web almost always start with http://, immediately followed by the web page address such as in this one ‘http://www.google.com/’.

·This is the root web site address of Google. And browsing to it, the server located at the address would serve up the home page of Google. This is all beyond the meaning of HTTP however, what this basically means is that, a web address consists of 2 basic parts: Protocol (HTTP) & Address (WWW.GOOGLE.COM).