3.0

3.0

1. GUIDED(WIRED)

   • TWISTED PAIR CABLE
     • 2 WIRES TWISTED
       • ONE RECIEVER THE OTHER A GROUNDER TWIST RATIO: # OF TWISTS PER METER. CHEAP, FLEXIBLE, HANDDLES FASTER NETWORKING, LOTS OF NOISE AND SHORT TRANSMISSION DATA
       • Unshielded
         • cheaper but more noise
       • Shielded
         • rare and costly but less noise
   • COAX CABLE
     • HIGHER FREQUENCY THAN TWISTED
       • USED MAINLY FOR RADIO, TV, RF
       • LESS NOISE THAN TWISTED
         • LESS FLEXIBLE
   • FIBER OPTIC
     • LED CENTER
       • MULTIMODE
         • STEP INDEX = CROSS X WITH A LINE
         • GRADED INDEX = SMOOTH SINE WITH LINE ACROSS
       • SINGLE MODE
       • LESS NOISE BUT VERY EXPENSIVE
         • HIGH SPEED FOR BACKBONE NETWORKING
         • REQUIRES CERTAIN EQUIPMENT TO SPLICE

2. UNGUIDED(UNWIRED

   • BROADCASTED ON FREE SPACE
     • RADIO WAVE
       • 3KHZ - 1GHZ
     • MICRO WAVES
       • 1GHZ-300GHZ
       • 5G RANGES FROM 30GHZ TO 300 GHZ
   • guided medium transport waves without using a physical conductor

3. QUIZ

   • 3.1
     • LAYER 1 PHYSICAL
       • HUB
         • ONLY LOOK AT BIT LEVEL NOTHING ELSE
           • AMPLIFY AND RE-TIME NETWORK FOR GREATER LENGTHS
             • SENDS DATA TO ALL PEOPLE CONNECTED TO HUB
               • DO NOT SEGMENT THE NETWORK
               • DOES NOT REDUCE NETWORK TRAFFIC
         • Segmentation is the breaking down of a single heavily populated network segment into smaller segments, or collision domains, populated by fewer nodes
         • Segment is part of a network that is divided logically or physically from the rest of the network
         • ices that “see” the traffic of other devices are said to be on the same collision domain
       • REPEATERS
     • LAYER 2 DATA LINK
       • BRIDGE
         • USES MAC ADRESSES
         • BREAKS LARGER NETWORKS INTO SMALLER SEGMENTS
           • ACTS LIKE A REPEATER
           • SUBDIVIDES NETWORK COMMUNICATIONS
           • REDUCES FRAME COLLISION
       • ETHERNET SWITCH
         • Switches combine the connectivity of a hub with the traffic regulation of a bridge on each port
           • learning of MAC address
           • Forwarding of frames
           • Avoiding loops
         • Switches increase available network bandwidth, thus increasing network performance
       • Broadcast stormWhen two or more stations engage in the transmission of excessive broadcast traffic
       • hen machines must share a wire and compete for available bandwidth with other machines, they experience Contention
       • MicrosegmentationPrevents communications between just two computers from being broadcast to every computer on the network or segment
     • LAYER 3
       • ROUTER
         • routers is a “layer 3 device”: creating signal in L1, checking MAC/physical address in L2, and checking IP addresses in L3
         • makes path selection decisions based on network address (for TCP/IP that’s the IP address)
         • routers are the backbone of the Internet
         • SLOWER THAN OTHER DEVICES TO ANILIZE DATA
   • 3.2
     • ANALOG SIGNAL
       • CONTINUOUS IN TIME AND VALUE
         • AMPLITUDE = STRENGTH
         • FREQUENCY = number of times amplitude cycles within one second
         • WAVELENGTH = tance between corresponding wave cycle points, expressed in metres/feet
         • PHASE = Wave’s progress over time in relationship to fixed point
     • ANALOG DATA
       • INFO THAT IS CONTINUOUS
     • DIGITAL DATA
       • INFO THAT HAS DISCRET STATES
     • DIGITAL SIGNAL
       • DISCRETE IN TIME AND VALUE
       • BINARY SYSTEM OF 1 AND 0
     • MODEM
       • ACCOMPLISHES TRANSLATIONS
         • echnology that uses analog signals to transmit digital data
     • CHANNEL = DISCTINCT COM PATHS BETWEEN NODES
   • 3.3
     • LAN
       • Ethernet LAN was developed in the 1970s by Robert Metcalfe and David Boggs at Xerox
     • ETHERNET
       • GIGABIT USES SWITCHES
       • 10GIGBIT USESES LAN AND MAN
       • IEEE 802.3 defined the Standard Ethernet (10Mbps)