Tuesday, March 27, 2012

Week 4

Chapter: Network hardware


Today, my entry will be on network hardware. But on top of that, let's just browse through the network architecture. There are two major types of network architecture:
a) Peer-to-peer

  • workstations connected to each other but do not have servers.
  • files can be shared between workstations and also the printers. 

b) client/server network

  • consists of two kinds of computers
  • clients are the workstations, servers are powerful computers and held in central locations.
  • need client software and server software
let's skip the architecture part and went straight to the hardware. what are the equipments available in network hardware?

1. Client - servers configuration
  • server - controls the communication of information between the nodes on a network. 
  • client/ workstations - all computers connected to the file server on a network
2. Network Interface Card
  • provides the physical connection between the network and the workstation
  • necessary to determine the speed and performance of network
3. Repeaters
  • connectors that take signals that is being transferred on a network and re-transmits the information.
  • allow signal to travel farther along a network
  • do not operate efficiently when they have to transfer large amount of information.
4. Hub/Switch
  • device that provides a central connection point for cables from workstations, servers and peripherals. 
  • multislot concentrators 
  • passive hubs - do not process information, connect wires to the network
  • active hubs - amplify signals to eliminate errors on the network.
5. Bridges
  • allows computer on individual networks or separate parts of a network to exchange information.
  • can only transfer information from one network to another. 
  • split an overloaded network into smaller parts.
6. Routers
  • link different networks together. 
  • analyse the information passing through to prevent looping problems. 
  • determine the best route for information
7. Gateways
  • link two different network types together. 
  • a hardware device that connect to the network physically and transfer information between them.
8. Modems

  • allow computers on a network to exchange information.
  • translates information into a form that can be transmitted over telephone lines
  • inexpensive way of communication


UTP Cable connectors
  • unshielded twisted pair cabling is an RJ-45 connector.
  • a plastic connector that looks like a large telephone-style connector. 
Coaxial cable connector
  • familiar from TV cable and VCR. 
Fibre optic connector

  • common used in fibre optic connector is the ST connector.

    Thursday, March 15, 2012

    Week 3

    few of my friends actually told me that my blog looks really simple. to me, the content of the blog should be precise and packed but in a brief way explained. I have another blog before, and believe me people hate to read long posts. so I choose to make my content simple yet precise.

    this week's chapter: Computer Networking and Network Topology

    we actually learn a bit about computer networking in the previous class, so i was just going to recall what we have learn.

    Computer Network: connecting computer to computer / devices
    It also enable communication between:
    a) Computer devices/equipment
    b) Transmission media to send/control data/signals
    c) Communication devices to transmit/send data from sources to destinations
    d) Softwares

    Many types of network exist, but the most common types are:
    a) Local Area Network (LAN)
    b) Wide Area Network (WAN)
    c) Metropolitan Area Network (MAN)
    d) Personal Area Network (PAN)

    the next chapter that we learn is the topology. topology is one way that the networks are being categorized. It specifies the geometric arrangement of the network. It has both logical and physical level in its structure.

    Physical level:
    - the way that devices on a network are arranged

    Logical level
    - the way the signals act on the network media/ the way that the data passes through

    we will go through one by one of this topology. first is the BUS NETWORK STRUCTURE.

    - a continuous length of cable that connects two or more devices together.
    - it can only transfer information one at a time.
    - each end of the cable on the bus network must have  a terminator ( a device that absorbs signal transmitted on a network cable)

    -consists of individual computer connected to a centre point of the network.
    -each computer is connected to a central network connector, called a hub.
    -It is commonly used as if there are error in one of the computers or cable, the rest of the network will be unaffected.

    -consists of individual computers connected to a single length of cable arranged in a ring.
    -information travels in one direction only
    -must be attached to a single ring cable

    -a mixture of many different kinds of network structure. It can incorporate structures such as ring, star, and bus network in one large network.

    that's all for now. It's a long entry. Well, we do learn a lot right? see you in my next entry! XD

    Tuesday, March 13, 2012

    Week 2~

    week 2: Data Communications

    my last post have been quite long huh? the days have been very busy and i completely forgot about my blog. i'll try and catch up very soon.

    our second chapter is the DATA COMMUNICATION. it is a collection and distribution of the electronic representation of information. it uses electrical transmission systems. Eg: Telephone lines, satellites or coaxial cable.

    first we learn about analog VS digital signal.

    this is the analog and digital signal    
    analog signals: signals like sound wave/image and it is continuous
    Eg: Standard phones, fax machines and modems.

    Digital signals: transmission of signals to a binary digit. It is also a series of on/off signals.

    p/s : process of changing analogue to digital is called modulation. the process of turning back is called demodulation.

    next, we will go to the data flow as known as the transmission directions.

    A) Simplex
    -one way communication (alarm, door bell, radio)

    B) Half-duplex
    -flow in two directions, but never in the same time. (walkie-talkie)

    C)Full duplex
    -can transmits and receive simultaneously (Internet connections, telephones)

    Monday, March 5, 2012

    introduction to telecommunication.

    this is my second entry of my new assignment blog. luckily i remember doing it. if i didn't, i'll be procrastinating a lot more.

    first chapter : Introduction to Telecommunication

    what is communication? to me, communication is an act of exchanging information with another parties. but that is only my opinion. the correct definition will be : an act of communicating that includes all of the procedures by which one mind may affect another.

    the communication process

    what is telecommunication then?

    most of my friends will answer, it is an act of communication using technology. i believed the same though. but that is not the how we are supposed to define it. it is a process of transmitting or receiving information over a distance by any electric or electromagnetic medium. it is also of process of communicating over a long distances. without telecommunication, how are we supposed to locate our friends? how can we contact our family that is so far away?

    it is all possible using telecommunications. while I was browsing through YouTube, i found this video about what happen when ICT is introduced and the result from the introduction.

    Leadership in telecommunications is also essential, since we are now in the age of e-commerce.
    Michael Oxley