keywords:
Bookmark and Share



Front Back
DATA COMMUNICATION
PEOPLE ARE LINKED BY WIRE OR AIR (WIRELESS) CARRYING DATA, VOICE, VIDEO AND COMPUTER SIGNALS VIA THE TELECOMMUNICATIONS SYSTEMS
TELECOMMUNICATIONS
ANY SYSTEM FOR COMMUNICATING OVER A LONG DISTANCE
COMPUTER NETWORK
THE LINKAGE OF COMPUTER SYSTEMS BY MEANS OF COMMUNICATION LINES OR CHANNELS (FIBER OPTIC, MICROWAVE, SATELLITE, TELEPHONE)
AUTOMATIC DATA COLLECTION (POLLING)
GATHERING DATA DAILY FROM EACH RESTAURANTS POINT OF SALE SYSTEM WITH THE HELP OF WAN
COMPUTER NETWORK
REFERS TO A COLLECTION OF COMPUTERS AND NETWORK HARDWARE INTERCONNECTED BY COMMUNICATION CHANNELS THAT ALLOW SHARING OF RESOURCES AND INFORMATION SUCH AS PRINTERS, APPLICATIONS, AND DATABASES
LOCAL AREA NETWORK (LAN)
LINKAGE OF COMPUTERS IN A SPECIFIC GEOGRAPHICAL AREA SUCH AS IN HOTELS, RESTAURANTS OR COUNTRY CLUBS USING A TRANSMISSION MEDIUM SUCH AS TWISTED PAIR WIRE OR COAXIAL CABLE
NOS
NETWORK OPERATING SYSTEM
SERVERS
DEVICES THAT SHARE THEIR RESOURCES
CLIENTS (NODES)
NETWORK OPERATING PROGRAMS THAT GIVE THE ABILITY TO USE THOSE SHARED RESOURCES
WORKSTATION
A COMPUTER THAT CAN REQUEST RESOURCES FROM THE NETWORK WHILE A CLIENT IS ANY NETWORK ENTITY SUCH AS A PRINTER OR FAX THAT CAN REQUEST RESOURCES FROM THE NETWORK.  (WORKSTATIONS CAN BE CLIENTS, BUT NOT ALL ARE WORKSTATIONS)
SERVER
PROVIDES RESOURCES TO THE CLIENTS ON THE NETWORK. USUALLY POWERFUL COMPUTERS THAT RUN NETWORK OPERATING SOFTWARE (NOS) SUCH AS LINUX, NOVELL OR WINDOWS SERVER 2012 THAT CONTROLS AND MAINTAINS THE NETWORK.
HOSTS
IN LAN ENVIRONMENTS, ALL OTHER NETWORKING DEVICES
NETWORK INTERFACE CARD (NIC)
PIECE OF COMPUTER HARDWARE DESIGNED TO ALLOW COMPUTERS TO COMMUNICATE OVER A COMPUTER NETWORK
MEDIA ACCESS CONTROL (MAC)
EACH NIC HAS THIS UNIQUE ADDRESS. USED IN SWITCHES TO RECOGNIZE THE STATIONS ATTACHED TO A NETWORK
SWITCH
A COMPUTER NETWORKING DEVICE THAT CONNECTS NETWORK SEGMENTS. BUILDS A TABLE OF ALL MEDIA ACCESS CONTROL ADDRESSES OF ALL STATIONS AND SENDS THE REQUESTS FOR DATA TRANSMISSION TO APPROPRIATE STATIONS, CLIENTS OR NODES.
HUB
SIMILAR JOB TO A SWITCH HOWEVER A HUB TRANSMITS ALL DATA TO ALL NODES REGARLESS OF THE SOURCE AND DESTINATION. A SWITCH TRANSMITS THE DATA ONLY TO THE DESTINATION COMPUTER
HUBS HAVE 2 CONTRAINTS
CLOGS THE NETWORK SINCE IT SENDS DATA TO ALL STATIONS THERE IS MORE TRAFFIC.
POSES SECURITY RISK SINCE IT DOES SEND DATA TO ALL STATIONS THERE IS A HIGH CHANCE OF UNAUTHORIZED USERS TO ACCESS SENSITIVE DATA
CABLE
A WIRED LAN REQUIRES CABLES TO CONNECT THE COMPUTERS TOGETHER
TPC
TWISTED PAIR CABLES: CONSISTS OF MULTIPLE INDIVIDUALLY INSULATED WIRES THAT ARE TWISTED TOGETHER IN PAIRS. RATED CAT 1, 2, 3, 4, 5, 5e (ENHANCED), 6, 7. CAT 5 AND HIGHER ARE ETHERNET CABLES. CAT 5 AND 5e ARE MOST COMMON IN LAN's.
COAXIAL CABLE
CONTAINS A CENTER CONDUCTOR MADE OF COPPER SURROUNDED BY A PLASTIC JACKET WITH A BRAIDED SHIELD OVER THE JACKET. USUALLY FOUND IN OLDER NETWORKS
FIBER OPTIC CABLE
GLASS OR PLASTIC FIBER THAT CARRIES LIGHT ALONG ITS LENGTH. THE FASTEST AND MOST EXPENSIVE TRANSMISSION MEDIUM IN THE WORLD TODAY.
ADVANTAGES OF FIBER OPTIC CABLE
  • SUPERIOR SYSTEM PERFORMANCE
  • GREATLY INCREASED BANDWIDTH AND CAPACITY
  • LOWER SIGNAL LOSS
  • IMMUNITY TO ELECTRICAL NOISE
  • IMMUNITY TO NOISE (ELECTROMAGNETIC INTERFERENCE AND RADIO FREQUENCY INTERFERENCE)
  • LOWER BIT ERROR RATES
  • SIGNAL SECURITY
  • DIFFICULT TO TAP
  • LIGHTWEIGHT
DISADVANTAGES OF FIBER OPTIC CABLE
  • COST
  • SENSITIVE, THEY DO NOT HANDLE EXTENSIVE BENDING
 
NETWORK TOPOLOGY
THE MANNER IN WHICH WORKSTATIONS ARE CONNECTED TOGETHER PHYSICALLY AND LOGICALLY
BUS TOPOLOGY
THIS PERMITS THE CONNECTION OF WORKSTATIONS AND PERIPHERAL DEVICES ALONG A CENTRAL CABLE. SIMPLE AND CHEAP TO SET UP HOWEVER THERE ARE OFTEN PROBLEMS WHEN TWO CLIENTS WANT TO TRASMIT AT THE SAME TIME ON THE SAME BUS.
ADVANTAGES OF BUS TOPOLOGY
  • EASY TO IMPLEMENT AND EXTEND
  • REQUIRES LESS CABLE LENGTH THAN A STAR TOPOLOGY
  • WELL SUITED FOR TEMPORARY OR SMALL NETWORKS NOT REQUIRING HIGH SPEEDS
  • CHEAPER THAN OTHER TOPLOGIES
DISADVANTAGES OF BUS TOPOLOGY
  • LIMITED CABLE LENGTH AND NUMBER OF STATIONS
  • IF THERE IS A PROBLEM WITH THE CABLE, THE ENTIRE NETWORK GOES DOWN
  • MAINTENANCE COSTS MAY BE HIGHER IN THE LONG RUN
  • PERFORMANCE DEGRADES AS ADDITIONAL COMPUTERS ARE ADDED OR ON HEAVY TRAFFIC
  • PRPER TERMINATION IS REQUIRED (LOOP MUST BE IN CLOSED PATH)
  • SIGNIFICANT CAPACITIVE LOAD (EACH BUS TRANSACTION MUST BE ABLE TO STRETCH TO MOST DISTANT LINK)
  • WORKS BEST WITH LIMITED NUMBER OF NODES
RING TOPOLOGY
PERMITS WORKSTATIONS TO BE CONNECTED TO EACH OTHER FORMING A CLOSED LOOP. REQUIRES LESS CABLE THAN A STAR NETWORK AND IS LESS SENSITIVE TO DISTANCE THAN A BUS TOPOLOGY SINCE EACH WORKSTATION IN THE RING REGENERATES THE SIGNAL. PRIMARY DISADVANTAGE OF A RING NETWORK IS THAT A FAILED WORKSTATION MIGHT BREAK THE RING. MAY BE USED IN DEPARTMENTS THAT HANDLE SENSITIVE DATA, SUCH AS ACCOUNTING AND HUMAN RESOURCES
STAR TOPOLOGY
MOST COMMON NETWORK. CONSISTS OF ONE CENTRAL SWITCH, HUB, OR COMPUTER WHICH ACTS AS A CONDUIT TO TRANSMIT MESSAGES.
WIDE AREA NETWORK (WAN)
LINKS COMPUTERS IN A LAN SET UP OVER A GREAT DISTANCE USING TELEPHONE LINES, FIBER OPTIC, SATELLITES, MICROWAVE STATIONS, CELLULAR BROADBAND TECHNOLOGY OR A COMBINATION OF THESE TRANSMISSION MEDIA. AT LEAST 2 LANs SHOULD BE CONNECTED TO EACH OTHER TO BE ABLE TO CREATE A WAN.
PRIVATE LINE
LEASED FROM THE CARRIER USUALLY ON A MONTHLY BASIS. THE CHARGE IS BASED ON BOTH THE CHANNEL CAPACITY (BITS PER SECOND) AND THE DISTANCE
FRAME RELAY
A VARIATION OF A PRIVATE LINE. A TELECOMMUNICATION SERVICE DESIGNED FOR COST EFFICIENT DATA TRANSMISSION FOR INTERMITTENT TRAFFIC BETWEEN LAN AND BETWEEN ENDPOINTS IN A WAN UTILIZING EXISTING T-1 AND T-3 LINES.
x of y cards