NETWORK TOPOLOGY

Network Topology Diagram Software

It is a new, rapid and powerful topology diagram software with diversified examples and templates. Therefore it has become so easy to draw network topology diagrams, network mapping, home network, wireless network diagram, Cisco network topologies, network cable diagrams, logical network diagrams, network wiring diagrams, LAN network diagrams, activity network diagrams, network topology diagrams, local network area diagrams, network physical diagrams, network security diagrams, network wan diagrams, network wiring cable diagrams, network cabling diagrams, and network voip diagrams.

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Network topologies are categorized into the following basic types: 

• Star Topology
• Ring Topology
• Bus Topology
• Tree Topology
• Mesh Topology
• Hybrid Topology

More complex networks can be built as hybrids of two or more of the above basic topologies.

Star Topology Many home networks use the star topology. A star network features a central connection point called a "hub" that may be a hub, switch or router. Devices typically connect to the hub with Unshielded Twisted Pair (UTP) Ethernet.

Compared to the bus topology, a star network generally requires more cable, but a failure in any star network cable will only take down one computer's network access and not the entire LAN. (If the hub fails, however, the entire network also fails.)

See the illustration of Star Network Topology.

Advantages of a Star Topology 

• Easy to install and wire.
• No disruptions to the network then connecting or removing devices.
• Easy to detect faults and to remove parts.

Disadvantages of a Star Topology 

• Requires more cable length than a linear topology. 
• If the hub or concentrator fails, nodes attached are disabled. 
• More expensive than linear bus topologies because of the cost of the concentrators.

The protocols used with star configurations are usually Ethernet or LocalTalk. Token Ring uses a similar topology, called the star-wired ring.

Star-Wired Ring

A star-wired ring topology may appear (externally) to be the same as a star topology. Internally, the MAU of a star-wired ring contains wiring that allows information to pass from one device to another in a circle or ring . The Token Ring protocol uses a star-wired ring topology.

Ring Topology In a ring network, every device has exactly two neighbors for communication purposes. All messages travel through a ring in the same direction (either "clockwise" or "counterclockwise"). A failure in any cable or device breaks the loop and can take down the entire network.

To implement a ring network, one typically uses FDDI, SONET, or Token Ring technology. Ring topologies are found in some office buildings or school campuses.

See the illustration of Ring Topology.

Bus Topology Bus networks (not to be confused with the system bus of a computer) use a common backbone to connect all devices. A single cable, the backbone functions as a shared communication medium that devices attach or tap into with an interface connector. A device wanting to communicate with another device on the network sends a broadcast message onto the wire that all other devices see, but only the intended recipient actually accepts and processes the message.

Ethernet bus topologies are relatively easy to install and don't require much cabling compared to the alternatives. 10Base-2 ("ThinNet") and 10Base-5 ("ThickNet") both were popular Ethernet cabling options many years ago for bus topologies. However, bus networks work best with a limited number of devices. If more than a few dozen computers are added to a network bus, performance problems will likely result. In addition, if the backbone cable fails, the entire network effectively becomes unusable.

See the illustration of Bus Network Topology.

Advantages of a Linear Bus Topology

1. Easy to connect a computer or peripheral to a linear bus.
2. Requires less cable length than a star topology.

Disadvantages of a Linear Bus Topology

1. Entire network shuts down if there is a break in the main cable.
2. Terminators are required at both ends of the backbone cable.
3. Difficult to identify the problem if the entire network shuts down.
4. Not meant to be used as a stand-alone solution in a large building.
   

Tree Topology Tree topologies integrate multiple star topologies together onto a bus. In its simplest form, only hub devices connect directly to the tree bus, and each hub functions as the "root" of a tree of devices. This bus/star hybrid approach supports future expandability of the network much better than a bus (limited in the number of devices due to the broadcast traffic it generates) or a star (limited by the number of hub connection points) alone.

See the illustration of Tree Network Topology.

Advantages of a Tree Topology

1. Point-to-point wiring for individual segments.
2. Supported by several hardware and software venders.

Disadvantages of a Tree Topology

1. Overall length of each segment is limited by the type of cabling used.
2. If the backbone line breaks, the entire segment goes down.
3. More difficult to configure and wire than other topologies.

Mesh Topology involve the concept of routes. Unlike each of the previous topologies, messages sent on a mesh network can take any of several possible paths from source to destination. (Recall that even in a ring, although two cable paths exist, messages can only travel in one direction.) Some WANs, most notably the Internet, employ mesh routing.

A mesh network in which every device connects to every other is called a full mesh. As shown in the illustration below, partial mesh networks also exist in which some devices connect only indirectly to others.

See the illustration of Mesh Network Topology.

Hybrid Topology

A combination of any two or more network topologies. Note 1: Instances can occur where two basic network topologies, when connected together, can still retain the basic network character, and therefore not be a hybrid network. For example, a tree network connected to a tree network is still a tree network. Therefore, a hybrid network accrues only when two basic networks are connected and the resulting network topology fails to meet one of the basic topology definitions. For example, two star networks connected together exhibit hybrid network topologies. Note 2: A hybrid topology always accrues when two different basic network topologies are connected

DATA COMMUNICATIONS

WHAT IS DATA COMMUNICATIONS?






Data communication refers to the exchange of data between a source and a receiver. Data communication is said to be local if communicating devices are in the same building or a similarly restricted geographical area.The meanings of source and receiver are very simple.The device that transmits data is known as source and the device that receives the transmited data is known as receiver.Data communication aims at the transer of data and maintenance of the data during the process but not the actual generation of the information at the source and receiver.



ELEMENTS OF DATA COMMUNICATIONS:

i) Information/data
ii) digital encoded
iii) sender or receiver
iv) medium

ELEMENTS OF NETWORK:

i) hardware equipments
ii) software
iii) communication channels
iv) information/data/resource
v) protocols

     Data Transmissions process between sender and receiver is refer to data communication and deployed physical environment (software/hardware/protocols/channels) is network.

TYPE OF DATA TRANSMISSION

 

 

 

 

 

SIGNAL is electronic or electromagnetic representation of data possibility analog or digital

 

REFLEKSI MINGGU 2 (KOMUNIKASI DATA)

Assalamualikum...

Saya Nuraliyyah Ainah bt Sajani merupakan mahasiswa dalam Ijazah Sarjana Muda Teknologi serta Pendidikan(Kemahiran Hidup) di sebuah universiti awam.Ini merupakan catatan saya yang pertama setelah mempelajari cara untuk membuat sebuah blog dan juga salah satu medium pembelajaran bagi saya.Pada sebelum ini saya tidak mengetahui bagaimana untuk membuat blog dan tidak tahu kegunaan blog secara terperinci.

Bagi refleksi pada minggu ke-2,saya telah mempelajari satu tajuk iaitu komunikasi data dalam subjek telekomunikasi dan rangkaian (SPPM 1013) yang diajar oleh Encik Abdul Razak bin Idris.Saya tidak faham apa yang dimaksudkan dengan komunikasi data dan semua yang berkaitan dengan data itu sendiri.Pelbagai medium yang saya gunakan untuk memahami komunikasi data dengan cara membuat pencarian melalui google.Daripada itu,saya dapat mengetahui serba sedikit tentangnya.Apabila masuk ke dalam kelas saya boleh memahami istilah yang digunakan dan pensyarah yang mengajar sangat membantu saya dalam memahami lebih jauh lagi tentang komunikasi data.
Sekian.Terima Kasih.