What's 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 anetwork 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 ofinformation 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-businessand 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 addressspace 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.

source : www.wikipedia.com

BlackBerry Playbook

SEOUL, KOMPAS.com — Research In Motion Ltd (RIM) berniat mengambil pasar tablet iPad milik Apple. Sebagai langkah awal, produsen ponsel pintar BlackBerry itu akan mulai menawarkan tablet komputer teranyarnya di Amerika Utara pada kuartal pertama 2011. Yang perlu menjadi perhatian Apple, RIM hanya membanderol BlackBerry Playbook di bawah 500 dollar AS.

"Harga produk ini sangat kompetitif sekali," ujar Co-Chief Executive Officer Jim Balsillie. Sayang, Balsillie belum mau buka-bukaan terkait harga pastinya. Namun, penjualan Playbook akan mengglobal dari kuartal II tahun depan. Sekadar perbandingan, Apple menjual iPad seharga 499 dollar AS.

Selain RIM, Hewlett-Packard Co, Samsung Electronics Co, dan Motorola Inc juga tengah mencari peruntungan lewat produk komputer tablet. Hal ini dilakukan setelah permintaan akan iPad kian meningkat saban hari. Dalam 80 hari pertama setelah debut, Apple berhasil menjual sekitar 3 juta iPad atau melampaui jumlah penjualan pemutar musik iPod.

Berdasarkan data Strategy Analytics, pangsa pasar tablet Apple meningkat menjadi 95 persen pada kuartal III 2010. Sementara itu, penjualan komputer tablet secara global melonjak 26 persen dari periode sebelumnya menjadi 4,4 juta unit. Dari angka tersebut, penjualan tablet Apple mencapai 4,19 juta unit. (Kontan/Barratut Taqiyyah)

Tree Topology

Tree

Tree network topology

Also known as a hierarchical network.

The type of network topology in which a central 'root' node (the top level of the hierarchy) is connected to one or more other nodes that are one level lower in the hierarchy (i.e., the second level) with a point-to-point link between each of the second level nodes and the top level central 'root' node, while each of the second level nodes that are connected to the top level central 'root' node will also have one or more other nodes that are one level lower in the hierarchy (i.e., the third level) connected to it, also with a point-to-point link, the top level central 'root' node being the only node that has no other node above it in the hierarchy (The hierarchy of the tree is symmetrical.) Each node in the network having a specific fixed number, of nodes connected to it at the next lower level in the hierarchy, the number, being referred to as the 'branching factor' of the hierarchical tree.This tree has individual peripheral nodes.

1.) A network that is based upon the physical hierarchical topology must have at least three levels in the hierarchy of the tree, since a network with a central 'root' node and only one hierarchical level below it would exhibit the physical topology of a star.

2.) A network that is based upon the physical hierarchical topology and with a branching factor of 1 would be classified as a physical linear topology.

3.) The branching factor, f, is independent of the total number of nodes in the network and, therefore, if the nodes in the network require ports for connection to other nodes the total number of ports per node may be kept low even though the total number of nodes is large – this makes the effect of the cost of adding ports to each node totally dependent upon the branching factor and may therefore be kept as low as required without any effect upon the total number of nodes that are possible.

4.) The total number of point-to-point links in a network that is based upon the physical hierarchical topology will be one less than the total number of nodes in the network.

5.) If the nodes in a network that is based upon the physical hierarchical topology are required to perform any processing upon the data that is transmitted between nodes in the network, the nodes that are at higher levels in the hierarchy will be required to perform more processing operations on behalf of other nodes than the nodes that are lower in the hierarchy. Such a type of network topology is very useful and highly recommended.

source : www.wikipedia.com