1. What is internet ?
The
Internet is a global system of interconnected computer networks that use the standard Internet Protocol Suite (TCP/IP) to serve billions of users worldwide. It is a
network of networks that consists of millions of private, public, academic, business, and government networks, of local to global scope, that are linked by a broad array of electronic and optical networking technologies. The Internet carries a vast range of information resources and services, such as the inter-linked hypertext documents of the World Wide Web (WWW) and the infrastructure to support electronic mail.
Most traditional communications media including telephone, music, film, and television are being reshaped or redefined by the Internet. Newspaper, book and other print publishing are having to adapt to Web sites and blogging. The Internet has enabled or accelerated new forms of human interactions through instant messaging, Internet forums, and social networking. Online shopping has boomed both for major retail outlets and small artisans and traders. Business-to-business and financial services on the Internet affect supply chains across entire industries.
The origins of the Internet reach back to the 1960s with both private and United States military research into robust, fault-tolerant, and distributed computer networks. The funding of a new U.S. backbone by the National Science Foundation, as well as private funding for other commercial backbones, led to worldwide participation in the development of new networking technologies, and the merger of many networks. The commercialization of what was by then an international network in the mid 1990s resulted in its popularization and incorporation into virtually every aspect of modern human life. As of 2009, an estimated quarter of Earth's population used the services of the Internet.
The Internet has no centralized governance in either technological implementation or policies for access and usage; each constituent network sets its own standards. Only the overreaching definitions of the two principal name spaces in the Internet, the Internet Protocol address space and the Domain Name System, are directed by a maintainer organization, the Internet Corporation for Assigned Names and Numbers (ICANN). The technical underpinning and standardization of the core protocols (IPv4 and IPv6) is an activity of the Internet Engineering Task Force (IETF), a non-profit organization of loosely affiliated international participants that anyone may associate with by contributing technical expertise.
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2. What is internet protocol? (IP Adress)
The
Internet Protocol (
IP) is the principal communications protocol used for relaying datagrams (packets) across an internetwork using the Internet Protocol Suite. Responsible for routing packets across network boundaries, it is the primary protocol that establishes the Internet.
IP is the primary protocol in the Internet Layer of the Internet Protocol Suite and has the task of delivering datagrams from the source host to the destination host solely based on their addresses. For this purpose, IP defines addressing methods and structures for datagram encapsulation.
Historically, IP was the connectionless datagram service in the original Transmission Control Program introduced by Vint Cerf and Bob Kahn in 1974, the other being the connection-oriented Transmission Control Protocol (TCP). The Internet Protocol Suite is therefore often referred to as TCP/IP.
The first major version of IP, now referred to as Internet Protocol Version 4 (IPv4) is the dominant protocol of the Internet, although the successor, Internet Protocol Version 6 (IPv6) is in active, growing deployment worldwide.
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3.What is the OSI model?
7) Application Layer : The application layer provider different services to the application. Example of services provided by this layer are file transfer, electronic messaging e-mail, virtual terminal access and
network management.
6) Presentation Layer : The Presentation layer is responsible for protocol conversion, date encryption/decryption, Expanding graphics command and the date compression. This layer makes the communications between two host possible.
5) Session Layer : This layer is responsible for establishing the process-to-process communication between the host in the network. This layer is responsible for establishing and ending the sessions across the network. The interactive login is an example of services provided by this layer in which the connective are re-connected in care of any interruption.
4) Transport Layer : This layer is responsible for end-to-end delivers of messages between the networked hosts. It first divides the streams of data into chunks or packets before transmission and then the receiving computer re-assembles the packets. It also guarantee error free data delivery without loss or duplications.
3) Network Layer : This layer is responsible for translating the logical network address and names into their physical address (
MAC address). This layer is also responsible for addressing, determining routes for sending and managing network problems such as packet switching, data congestion and routines.
2) Data Link Layer : Data link layer is responsible for controlling the error between adjacent nodes and transfer the frames to other
computer via physical layer. Data link layer is used by hubs and switches for their operation.
1) Physical Layer : Physical Layer is responsible for transmitting row bit stream over the physical cable. The physical layer defines the hardware items such as cables, cards, voltages etc.
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4.
What is internet infrastructure?
With the growth of the Internet for personal use (e.g. Facebook, Amazon, Google, Gmail) and business purposes (i.e.file storage, web applications, collaboration and communication, VOIP) I thought it would be useful to talk about what actually powers all these things. I have a secondary reason for this too – when a non-technical person asks me what I do for a living, I have yet to come up with a short simple answer that actually explains it!
First of all, let me define what I mean by ‘Internet Infrastructure’. All the hardware and services required to make this web page appear in your browser, or an RSS feed download into your reader, or VOIP calls / emails get to your desktop. All the underlying technologies that are unseen, but ‘make the Internet go’.
I see Internet Infrastructure consisting of a ‘Top 5′ areas :
- Data Centres
- Network Connectivity
- Computer Equipment
- Storage Services
- Server Applications
Data Centre
A Data Centre is basically a specialist building that has the ability to power (and cool) massive amounts of computer equipment. Typically a Data Centre would also have a very large amount of network bandwidth to accommodate data transfer in and out of it. Data Centres are built as highly redundant and resilient facilities – at the base level – you would expect a Data Centre to have at least N+1 power (this likely comes as a local feed from the national electrical grid as ‘N’, and a backup generator for the ‘+1′).
The Data Centre is the home for Internet Infrastructure. It is the central point of aggregation and distribution of data and network services. These facilities tend to include:
- 24 x 7 Staffed Operations Centre (typically called a NOC, the staff monitor all activities of the Data Centre and ensure smooth operation as well as deal with equipment issues)
- Building Management System (the BMS normally monitors and alerts on temperature zones, power and cooling usage, outside temp., access control and CCTV)
- Secure Access Controls (i.e biometrics on all entry and DC floor doors)
- Fire Alarm and Suppression (ie. VESDA for detection and Inergen gas for suppression)
The unit of measurement for a Data Centre is space and power. How much space will the equipment require and how much power will it draw (which is effectively double that, as cooling a server takes about as much power as just having the device operating).
Network
Possibly to most important foundation block of Internet Infrastructure is the Network. Without a network connection no data can pass between Data Centres, over the Internet, and ultimately onto your Desktop, Laptop or Mobile Handset. For the purpose of this post, let’s talk about the network infrastructure in a Data Centre, where data passed in to computer equipment, is processed and/or stored, and passed back out of the DC.
So you would expect at least N+1 network connectivity into a Data Centre in the form of at least 2 Fibre Cables from telecommunications providers on diverse rings. Therefore if one had service cut, the Data Centre’s network connection would not be affected. Some data centres (Hosting365’s is one) are Carrier Neutral – which means a number of carriers have a Point-Of-Presence in the facility, so the Data Centre is not affected by any commercial or technical issues of a single carrier.
Next you would expect redundant switch gear in the Data Centre in separate racks so again if the switch gear failed, the other set of it would simply take over and no service interruption would be experienced.
The unit of measurement for network connectivity is megabits per second and available megabits on the carrier connection. There may be 1 Gigabit available but the DC may only be using, and paying for, 100 megabits. The ability to meet peak demand is important though, so Data Centres will have a lot more connectivity available than is required for daily operations.
Computer Equipment
Now that the two basics of Internet Infrastructure are in place – the ability to power your equipment, and the ability to connect it to the Internet, the next thing is the computer hardware that uses this to process and store the applications and data.
By computer equipment, for this basic post, I really mean Servers. A Server is a more complex and high-end version of a desktop PC. An average server might consist of 2 power supplies (for redundancy), 8-12 RAM slots, anything from 2-10 hard drive bays and multiple processors (not just multi-core!).
Servers are housed in Racks in a DC which are typically 42u in height. (1U is 1-unit and a low-end server takes up just 1 of these units, other servers scale within these racks to multiple ‘U’). Racks are normally powered by 2 PDU (Power Distribution Units) which connect to (if available) multiple power supply units in the server.
A low-end installation may be only a single server, which is the simplest form of Internet Infrastructure. The server would be connected to the DC Power, the Network, an OS and other required applications installed on it. Then it is ready to ‘power and push’ data on the Internet. More complex deployments would include pools of servers, with different applications on each one, or clusters of pools for multiple clusters with dedicated application requirements.
The unit of measure for Servers is Processor Power and RAM. Although there is a lot more to selecting a server such as expandability, reliability, network ports, BUS speed, Cache size and speed. Personally I would like the unit of measure in Servers to change, I think for buyers and users it should be rated in ‘MIPS’ – which is ‘Millions of Instructions Per Second’ which is effectively all that matters, and how today’s Mainframe computers (IBM BlueGene is a high end Mainframe) are measured.
Storage Services
Data Storage is a huge part of Internet Infrastructure. All those emails accessible online, all the web pages on your favourite web site, all those photos on Facebook … are all stored on a hard drive in a DC somewhere. The basic level of storage is on-server storage, which means the hard drives in the computer server. This can cause not just performance and capacity issues, but also redundancy ones – local storage is inherently as prone to failure as the server it is in.
It is common to use specific storage devices – such as Direct Attached Storage (a dedicated and dumb storage appliance connected direct to your server), Network Attached Storage (a storage device that can be accessed by multiple machines over a network connection, and independent of the server itself) and Storage Area Networks, which are high-end, resilient and redundant set-ups that give high performance levels and are very scalable. A Storage Area Network may be shared among many services, applications, servers and customers.
The unit of measure in storage is gigabytes (getting to be more commonly terabytes now) and IO’s per second (input-output read/writes the device can perform per second).
Server Applications
The final piece of underlying Internet Infrastructure is the server applications themselves. In order for an web application to be delivered from a server, that server requires an Operation System (typically Windows or Linux), a Web Server application (like Apache or Microsoft IIS), and a Database (such as MySQL, MS-SQL or Oracle). There any many more variations here, but the basic web server has these 3 things. From here you can install blog software, an ecommerce site, your new web 2.0 application, or any Internet capable piece of software (more include – Instant Messaging Server, File Storage Server, Message Board)
More complex applications tend to have dedicated servers, or pools or servers, for specific things – like a cluster of Database Servers, or a pool of Web Server to serve those ‘www.’ page requests. These may also have more complex network setup such as dedicated routers, load balancing and firewall devices (for traffic management and security respectively).
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5. What is Domain name?
A
domain name is an identification label that defines a realm of administrative autonomy, authority, or control on the Internet, based on the Domain Name System (DNS).
Domain names are used in various networking contexts and application-specific naming and addressing purposes. They are organized in subordinate levels (subdomains) of the DNS root domain, which is nameless. The first-level set of domain names are the top-level domains (TLDs), including the generic top-level domains (gTLDs), such as the prominent domains
com,
net and
org, and the country code top-level domains (ccTLDs). Below these top-level domains in the DNS hierarchy are the second-level and third-level domain names that are typically open for reservation by end-users that wish to connect local area networks to the Internet, run web sites, or create other publicly accessible Internet resources. The registration of these domain names is usually administered by domain name registrars who sell their services to the public.
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6. What is world wide web? and its services?
The
World Wide Web, abbreviated as
WWW and commonly known as
the Web, is a system of interlinked hypertext documents accessed via the Internet. With a web browser, one can view web pages that may contain text, images, videos, and other multimedia and navigate between them by using hyperlinks. Using concepts from earlier hypertext systems, English engineer and computer scientist Sir Tim Berners-Lee, now the Director of the World Wide Web Consortium, wrote a proposal in March 1989 for what would eventually become the World Wide Web
. At CERN in Geneva, Switzerland, Berners-Lee and Belgian computer scientist Robert Cailliau proposed in 1990 to use "HyperText [...] to link and access information of various kinds as a web of nodes in which the user can browse at will",
and publicly introduced the project in December
.
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7. how many current internet users in Thailand?
As of 2008, there were 16,100,000 Internet users in Thailand.
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