Multimedia

Multimedia is media and content that uses a combination of different content forms. The term can be used as a noun (a medium with multiple content forms) or as an adjective describing a medium as having multiple content forms. The term is used in contrast to media which only use traditional forms of printed or hand-produced material. Multimedia includes a combination of text, audio, still images, animation, video, and interactivity content forms.
Multimedia is usually recorded and played, displayed or accessed by information content processing devices, such as computerized and electronic devices, but can also be part of a live performance. Multimedia (as an adjective) also describes electronic media devices used to store and experience multimedia content. Multimedia is distinguished from mixed media in fine art; by including audio, for example, it has a broader scope. The term "rich media" is synonymous for interactive multimedia. Hypermedia can be considered one particular multimedia application.

Perang Cyber

Perang cyber antara hacker Indonesia melawan hacker Australia telah dimulai. Hacker kedua negara sudah saling melakukan serangan Distributed denial of Service (DdoS)ke server-server negara lawan sejak pertengahan bulan ini.

Perihal saling serang ini diungkapkan Predator, seorang hacktivis dari kelompok hacker "Hiddenline" kepada detikcom, Kamis (28/11/2002). Menurutnya serangan DdoS hacker Australia ke sebuah ISP di Yogyakarta bisa jadi merupakan serangan balasan.

"Saya rasa itu mungkin balasan dari pihak Aussie atas aktivitas DdoS yang datang dari Yogyakarta.Anggota kami pertengahan bulan ini aktif menyerang 203 (prefiks nomor IP Australia - Red) secara DdoS", tulis Predator dalam emailnya.

Serangan tersebut menurut Preadator dilakukan dari Yogyakarta dan tercatat memiliki nomor IP dari daerah tersebut.

Seperti diberitakan detikcom sebelumnya, selama satu pekan terakhir, sebuah perusahaan internet service provider (ISP) di Yogyakarta berulang kali terkena serangan DdoS yang dilakukan melalui ISP Telstra Internet di Canberra, Australia.

Hacker tersebut melakukan serangan DdoS melalui port User Datagram Protocol (UDP). Akibat serangan ini, bandwith ISP tersebut menjadi penuh sesak dan para pelanggan tidak dapat melakukan akses internet sebagai mana mestinya.

Saling serang antara hacker Indonesia dan Australia dimulai dengan serangan mass defacing hacker Indonesia ke situs-situs internet Australia. Serangan cyber ini disulut aksi sweeping gaya Rambo yang dilakukan pihak kepolisian dan badan intelejen ASIO terhadap warga negara Indonesia di Australia akhir bulan lalu.

Perang cyber kali ini bukan yang pertama kali bagi kalangan hacker Indonesia. Pada 1998, sempat terjadi perang cyber melawan hacker-hacker Cina pasca kerusuhan Mei tahun itu. Pada 1999 terjadi perang cyber melawan Portugis sebelum jajak pendapat di Timor Timur.

Perang cyber melawan Portugis berubah menjadi perang cyber melawan Australia ketika negara tersebut mulai turut campur setelah terjadinya kerusuhan pasca jajak pendapat.

Jenayah Cyber

JENAYAH tidak hanya berlaku di alam nyata sebaliknya dalam perkembangan teknologi maklumat yang semakin pantas dan sentiasa berubah setiap masa ia dapat berlaku hanya dengan menaip di papan kekunci komputer.

Bagaimanapun ramai pengguna komputer tidak tahu bagaimana mendapat maklumat atau perlindungan sekiranya berlaku sesuatu mencurigakan seperti pencerobohan ke atas komputer, laman web atau emel.

Pertama kali diperkenalkan pada 1997 dan dikenali sebagai Malaysian Computer Emergency Response Team (MyCert) di bawah kendalian MIMOS Berhad (MIMOS) bertujuan mengawal selia pengguna internet di Malaysia.

Bagaimanapun, pada 24 Januari 1998 MyCERT diberi peranan yang lebih luas dan dijadikan sebagai National ICT Security and Emergency Response Centre (NISER) untuk mengawal ICT negara.

NISER dirasmikan oleh Perdana Menteri Datuk Seri Abdullah Ahmad Badawi pada 10 April 2001. NISER kemudian dikeluarkan dari MIMOS dan dijadikan entiti berasingan dan dikenali sebagai CyberSecurity Malaysia pada Mac 2007.

Pemangku Ketua Pegawai Eksekutif CyberSecurity Malaysia, Lt Kol (B) Husin Jazri, berkata agensi di bawah Kementerian Sains Teknologi dan Inovasi (MOSTI) itu akan menjadi pusat rujukan pakar keselamatan siber kepada mana-mana agensi kerajaan lain dan syarikat swasta, termasuk orang perseorangan bagi mendapatkan khidmat nasihat berkaitan dengan keselamatan dan pencegahan jenayah di alam siber.

“CyberSecurity Malaysia beroperasi sebagai syarikat kerajaan bukan berlandaskan keuntungan dan berada di kawalselia MOSTI.

“Agensi ini juga bukan badan penguatkuasa, sebaliknya agensi teknikal yang boleh membantu pengguna internet menangani ancaman siber serta memberi khidmat nasihat dan bertindak sebagai biro aduan awam bagi pengguna internet.

“CyberSecurity Malaysia adalah agensi teknikal dan menjadi biro pengaduan kepada pengguna dalam menyelesaikan masalah keselamatan internet di Malaysia,’ katanya.

CyberSecurity Malaysia ialah pusat koordinasi setempat untuk keselamatan pengguna siber kebangsaan dan ditubuhkan dengan objektif untuk melindungi, membimbing, promosi di samping merangka strategi dalam menangani isu keselamatan siber di Malaysia.

Peranan CyberSecurity Malaysia membabitkan pencegahan jenayah di samping mempromosikan standard dan pengalaman terbaik keselamatan maklumat, membantu mangsa jenayah siber, juruperunding kepada Kerajaan dan mengurangkan pencerobohan ke atas sistem dan rangkaian teknologi maklumat di Malaysia.

Menerusi CyberSecurity Malaysia lima perkhidmatan diperkenalkan kepada orang ramai iaitu ‘Cyber999 atau Tindakbalas Kecemasan Komputer’, ‘Forensik Siber’, ‘Jaminan Keselamatan Maklumat’, ‘Pengurusan Keselamatan Maklumat ’ dan ‘Latihan dan Pembudayaan”.

Orang ramai yang berdepan dengan masalah keselamatan siber boleh mendapatkan khidmat daripada CyberSecurity yang beroperasi bermula jam 8.30 pagi hingga 5.30 petang hari Isnin hingga Jumaat. CyberSecurity Malaysia juga membuka komunikasi kecemasan 24 jam melalui emel, sms dan telefon.

Differencess between internet,intranet,extranet

Internet: Is now the World Wide Web (WWW) network of computers that is dispersedly managed with minimal restriction. It is what you have asked this question over.
Intranet: Operates much the same as the Internet but is restricted to a single corporate entity that has full control and management over it. Able to maximize restrictions over users.
Extranet: is an extension of an Intranet over the Internet for remote users. Typically it is heavily restricted for security reasons to a virtual private network (VPN) connection for Telecommuters or other offsite users.
Ethernet is the standard cable for computers to hook up to the network. It is also used for network devices (Routers, modems & switches) to interface with each other.

Bus topology

A bus topology connects each computer (nodes) to a single segment trunk (a communication line, typically coax cable, that is referred to as the 'bus'. The signal travels from one end of the bus to the other. A terminator is required at each to absorb the signal so as it does not reflect back across the bus. A media access method called CSMA/MA is used to handle the collision that occur when two signals placed on the wire at the same time. The bus topology is passive. In other words, the computers on the bus simply 'listen' for a signal; they are not responsible for moving the signal along.

Star topology

Star networks are one of the most common computer network topologies. In its simplest form, a star network consists of one central switch, hub or computer, which acts as a conduit to transmit messages.[1] Thus, the hub and leaf nodes, and the transmission lines between them, form a graph with the topology of a star. If the central node is passive, the originating node must be able to tolerate the reception of an echo of its own transmission, delayed by the two-way transmission time (i.e. to and from the central node) plus any delay generated in the central node. An active star network has an active central node that usually has the means to prevent echo-related problems.

The star topology reduces the chance of network failure by connecting all of the systems to a central node. When applied to a bus-based network, this central hub rebroadcasts all transmissions received from any peripheral node to all peripheral nodes on the network, sometimes including the originating node. All peripheral nodes may thus communicate with all others by transmitting to, and receiving from, the central node only. The failure of a transmission line linking any peripheral node to the central node will result in the isolation of that peripheral node from all others, but the rest of the systems will be unaffected. [2]

It is also designed with each node (file servers, workstations, and peripherals) connected directly to a central network hub, switch, or concentrator.

Data on a star network passes through the hub, switch, or concentrator before continuing to its destination. The hub, switch, or concentrator manages and controls all functions of the network. It is also acts as a repeater for the data flow. This configuration is common with twisted pair cable. However, it can also be used with coaxial cable or optical fibre cable.

Contents [hide]
1 Advantages
2 Disadvantages
3 References
4 See also

Ring topology

A ring network is a network topology in which each node connects to exactly two other nodes, forming a single continuous pathway for signals through each node - a ring. Data travels from node to node, with each node along the way handling every packet.

Because a ring topology provides only one pathway between any two nodes, ring networks may be disrupted by the failure of a single link[1]. A node failure or cable break might isolate every node attached to the ring. FDDI networks overcome this vulnerability by sending data on a clockwise and a counterclockwise ring: in the event of a break data is wrapped back onto the complementary ring before it reaches the end of the cable, maintaining a path to every node along the resulting "C-Ring". 802.5 networks -- also known as IBM Token Ring networks -- avoid the weakness of a ring topology altogether: they actually use a star topology at the physical layer and a Multistation Access Unit (MAU) to imitate a ring at the datalink layer.

Many ring networks add a "counter-rotating ring" to form a redundant topology. Such "dual ring" networks include Spatial Reuse Protocol, Fiber Distributed Data Interface (FDDI), and Resilient Packet Ring.