TRANSFER OF DATA IN ICT SYSTEMS

TRANSFER OF DATA IN ICT SYSTEMS

1. TYPES OF NETWORK

   • LAN - LOCATED IN ONE BUILDING OR ONE SITE AND ORGANISATIONS OWN THE EQUIPMENT
   • WAN - LINKED ACROSS LARGE GEOGRAPHICAL AREAS E.G. COUNTRIES/CONTINENTS AND ARE USUALLY COMMUNICATION NETWORKS

2. COMMUNICATION DEVICES

   • NIC - NETWORK INTERFACE CARDS ARE VITAL TO ALLOW A CONNECTION BETWEEN THE CABLE AND THE COMPUTER. IT CONVERTS THE DATA TO A FORMAT, WHICH CAN BE TRANSMITTED THROUGH THE NETWORK MEDIA.
   • HUB - JOINS TWO COMPUTERS TOGETHER SO THEY CAN SHARE FILES AND AN INTERNET CONNECTION.
   • SWITCH - JOINS MULTIPLE COMPUTERS TOGETHER AND INSPECTS PACKETS OF DATA SO THEY ARE FORWARDED APPROPRIATELY
   • ROUTERS - JOIN SEVERAL WIRED/WIRELESS NETWORKS TOGETHER. OFTEN USED BY HOME COMPUTERS WITH A SINGLE CONNECTION

3. DATA TRANSFER MEDIA

   • UNSHIELDED TWISTED PAIR - CANCEL INTERFERENCES, EASIER TO INSTALL. OFTEN USED FOR SMALL NETWORKS.
   • SHIELDED TWISTED PAIR - PROTECTS DATA SIGNALS FROM INTERFERENCE, MORE EXPENSIVE WITH GREATER TRANSMISSION SPEED.
   • FIBRE OPTIC CABLE - DATA BEING PASSED IS ENCODED INTO PULSES OF LIGHT THROUGH A THIN GLASS TUBE
     • ADVANTAGES: SPEED, SMALL SIZE, LACK OF ELECTRICAL INTERFERENCE
     • DISADVANTAGES: COST

4. NETWORK TOPOLOGIES

   • RING - DATA IS SENT BY ONE COMPUTER AND PASSED TO THE REST UNTIL IT REACHES THE CORRECT COMPUTER.
     • ADVANTAGES: EASY TO ADD OTHER COMPUTERS, EACH COMPUTER HAS THE SAME ACCESS
     • DISADVANTAGES: THE WHOLE NETWORK FAILS IF THERE IS A SINGLE BREAKAGE, FAULTS ARE DIFFICULT TO LOCATE, ONLY ONE PATH FOR THE DATA TO FOLLOW.
   • BUS - ALL DEVICES ARE CONNECTED TO A SHARED CABLE. SIGNALS ARE PASSED IN EITHER DIRECTION.
     • ADVANTAGES: COST EFFECTIVE, EASY INSTALLATION, EASY TO ADD OTHER DEVICES.
     • DISADVANTAGES: NETWORK FAILS IF THERE IS A BREAKAGE IN THE CABLE, THE PERFORMANCE DEGRADES IF 12 OR MORE COMPUTERS ARE CONNECTED.
   • STAR - USES A CENTRAL CONNECTION POINT TO CONNECT ALL DEVICES TOGETHER.
     • ADVANTAGES: