1. Chapter 4 Intro to Routing & Switching

2.  Upon completion of this chapter, you should be able to:  Describe the purpose of the physical layer  Identify characteristics of copper cabling  Make a UTP cable  Describe fiber optic cabling & its advantages  Describe wireless media  Select the appropriate media to connect devices  Describe the data link layer, its purpose & structure of a frame  Compare logical & physical topologies  Describe media access control

3.  What does the data link layer do to help send data?  What does the physical layer do to help send the data?  What does the physical layer do to help receive data?  What does the data link layer do to help receive data?

4. 4.1.1

5.  Connect wired or wirelessly  Switch, WAP, or ISR

6.  How do you connect to a wired network?  NIC  How do you connect to a wireless network?  WLAN NIC  What are disadvantages of wireless?  Distance from WAP (can use extender)  Sharing of wireless signal (more=slower)

7. 4.1.2

9.  Copper  Electrical pulses  Fiber  Light  Wireless  Radio waves  All follow standards so they can communicate together  ISO (RJ-45), EIA/TIA (568B), IEEE (802.3, 802.11), and others

10.  Identify network devices & cabling

13. 4.1.3

14.  Physical components  Cabling, NICs, connectors, ports/interfaces  Encoding  Pattern of voltage for 1’s & 0’s Differentiates data from control bit info The patterns indicate start & end of frame  Signaling  It’s what represents a 0 or 1/like Morse code  Volts/no volts; short pulse of light/long; type of radio wave  Random timing between signals (Asynchronous) or set time (clock) between signals (synchronous)

15.  Speed/capacity a media can handle  Like size of a hose  Bigger hose= more water through it

16.  Measure of transfer of bits over a time  Varies on amount & type of traffic, latency (delay)  Can only be as fast as the slowest link

17.  The measure of usable data transferred over a given period of time.  Throughput - traffic overhead  Example: Ethernet is 100Mbps Throughput is 85Mbps If traffic overhead is 15Mbps, then goodput is 70Mbps

18.  What’s the difference?  Type of copper cabling  Bandwidth it can handle  Type of connectors used  Wiring order & colors  Max distance

20.  GCIT’s Ethernet is 1000Mbps. It’s throughput is 800Mbps. If overhead is 10Mbps, what is the goodput?  790Mbps  Why are encoding methods (patterns for the bits) used by the physical layer?  So the code can be recognized  Distinguishes data from control bits  Tells where frame starts and ends  An asynchronous signal means what?  No clock signal sent

21.  Morse code & the timing between the bits is known as what?  Signaling  The speed or capacity of your media is what?  Bandwidth  The actual amount of bits/data that can actually pass over a period of time is what?  Throughput  The more bandwidth you have, the more __________________ you should have.  Throughput

22. 4.2.1

23.  Inexpensive & easy to install  Look up a box of Cat 5e 500ft spool  Electrical pulses  Distance limit (attenuation)  Interference from EMI/RFI, crosstalk  To avoid problems, select the right cable for the right situation

24.  UTP, STP, Coaxial

25.  Most common  RJ-45 connectors  8 wires, 4 twisted pairs  Twisting prevents crosstalk  Color coded

26.  Better EMI/RFI protection  More expensive to buy & install  RJ-45  8 wires, 4 twisted pair wrapped in foil

27.  Used in very early Ethernet & now for TV  Wireless antenna connections  Cable Internet  Shielding  Thicker cable  BNC or F-connector

28.  Flammable  Electrical hazard; attracts lightning

30.  What in the ceiling could “mess up” the electrical signal in an UTP cable?  Lights, electrical boxes/equipment  Radio waves cause what kind of interference?  RFI  An electrical motor near a UTP cable causes what kind of interference?  EMI  Signals from one cable jump into another. What problem is this?  Crosstalk

31.  Excessively long cable runs cause what problem?  Attenuation, signal gets weaker  What is the solution to prevent crosstalk?  Twisting of the pairs  Which cables have shielding?  STP & coaxial  What kind of connector is on UTP & STP?  RJ45

32. 4.2.1

33.  What does the twisting do?  No shielding so it relies on cancellation  Wires are paired for this & twisted a certain distance apart  RJ45 connector

34.  Cat 3, 5/5e, 6  Based on bandwidth rates

35.  Straight-through  We’re going to make them  Crossover  We’re going to make them  Rollover (Cisco’s)  Connect to console port  568B to reverse

36.  TIA/EIA 568A & 568B

37.  568B to 568B  Connect unlike devices  Computer to Hub/Switch  Switch to router port  On the PC NIC  Pins 1 & 2 transmit  Pins 3 & 6 receive

38.  Straight-through  568B to 568B  White-Orange  Orange  White-Green  Blue  White-Blue  Green  White-Brown  Brown

39.  568A to 568B  Like Devices  Switch/hub port to switch/hub port  Router port to router port  PC to router port  PC to PC

40.  Crossover  568B to 568A  Change Oranges & Greens on ONE SIDE!  White-Green  Green  White-Orange  Blue  White-Blue  Orange  White-Brown  Brown

41.  What is the 568B color order?  Wor/Or, WGr/Bl, WBl/Gr, WBr/Br  For speeds of 1000Mbps or more, what Category cable should be used?  Cat 6  What cable…  Goes between same devices? Crossover  Goes from PC to switch? Straight through  Goes from serial to console port? Rollover

42.  What colors do you change for a crossover cable?  Oranges & greens  What pairs transmit?  1 & 2  What pairs receive?  3 & 6

43. 4.2.3

44.  Transmits pulses of light  Laser or LED  Used for long distance  Glass or plastic  No EMI/RFI; no lightning attraction  High speed  LAN backbone  Connect ISP to Internet  2 fibers cables used  Transmit & receive

45.  Multimode  LED  Many paths of light  Used in LANs/Campuses 2000 meters  Less $, used more  Single Mode  Laser light  Single path of light  Connects backbone/NOCs 3000 meters  More $, faster speed

47. IssueUTPFiber Optic Bandwidth Distance Immunity to EMI/RFI Immunity to Electrical Hazards Media/Connector cost Installation Skill/Cost Safety Precautions

49.  Which cable is more expensive, copper or fiber?  Fiber  Which cable allows data to travel further, copper or fiber?  Fiber  Why are two strands of fiber used for communication?  Light can only travel in one direction at a time. This will allow for full-duplex.

50.  What signal travel on a single-mode cable?  Laser  Which cable would be used to go further distances?  Single mode  Why would you use fiber between buildings rather than copper?  Fiber does not attract lightning

51. 4.2.4

52.  Many devices use wireless  Cordless Phones 2.4GHz Interference  Microwave Ovens Interference  Range  Solid Walls a problem  Not as fast as, or reliable as, wired  Security  Wireless is east to access & can be intercepted Authentication & Encryption now used

53.  Specifies data speed, range, RF spectrum  IEEE standards, Wi-Fi  802.11a, 802.11b, 802.11g and 802.11n  Wi-Fi Alliance tests devices from manufacturer  Will work with other devices w/ same logo

54.  1999  2.4GHz  11Mbps  150ft range indoors  300 ft range outdoors

55.  1999  5GHz  Unused at that time  Less congestion  54Mbps (faster than B)  NOT compatible with b/g/n  75ft-150ft range  Originally too expensive  Now hard to find

56.  2003  2.4GHz  54Mbps  150ft range indoors  300 ft range outdoors  Compatible with 802.11b

57.  2.4Ghz  100-600Mbps  Up to 750ft range  Backwards compatible b/g

58.  Access Point (AP)  Connects wireless devices to wired network  Wireless NIC adapter  Gives wireless to a host

59. Standard Maximum Speed Frequency Backwards compatible 802.11a 802.11b 802.11g 802.11n 802.11ac

60. Standard Maximum Speed Frequency Backwards compatible 802.11a 54 Mbps5 GHzNo 802.11b 11 Mbps2.4 GHzNo 802.11g 54 Mbps2.4 GHz802.11b 802.11n 600 Mbps2.4 GHz or 5 GHz802.11b/g 802.11ac 1.3 Gbps (1300 Mbps) 2.4 GHz and 5.5 GHz802.11b/g/n 802.11ad 7 Gbps (7000 Mbps) 2.4 GHz, 5 GHz and 60 GHz 802.11b/g/n/ac

61.  Maybe???  Doesn’t really show wireless

62.  You’d like to add wireless with speeds up to 1.3Gbps. Which spec should you buy?  802.11ac  What is the max speed of G?  54Mbps  What connects wireless devices to a wired network?  AP  What wireless spec is no compatible with others?  802.11a

63.  What could interfere with a wireless signal?  Cordless phones, microwaves, solid walls  What are 2 other concerns with wireless networks?  Security and distance  802.11b, g, and n all operate on what frequency?  2.4GHz

64. 4.3.1

65.  TCP/IP equivalent?  Data link layer jobs:  Takes layer 3 packets & encapsulates into frames  Controls access to the media/encapsulates for the media being used  MAC addressing

66.  LLC  Closer to layer 3  Identifies what layer 3 protocol is being used  MAC  Closer to layer 1; rules for accessing media  MAC address  Ready for convert to any type of bits/media

67.  Encapsulates data into a frame  Adds frame header & trailer  Signifies beginning and end of packet

68.  What layer of the OSI generates the electrical signals?  Physical layer  What layer decides the best path?  Network layer  What layer handles the encapsulation for the proper media going to be used?  Data link layer  What are the 2 sublayers of the Data Link layer?  LLC & MAC

69.  What signifies the beginning & end of a frame?  Header & trailer  Which sublayer identifies the network protocol being used?  LLC

70. 4.4.1

71.  Rules of the rode way  Depends on:  Topology  Media sharing Point-to-point WAN connection (between 2 routers) Shared connection (LAN)

74.  Full duplex  Half duplex

76.  Either all complete for the line or take turns  This is MAC (Media Access Control) at Layer 2  CSMA/CD (ETHERNET)  Listen for silence, transmit  Collision= all backoff random time, listen for silence, retransmit  CSMA/CA (WIRELESS)  Listen for silence, notify all you are sending, gets clearance to send, transmits  Token Passing (OLD for Token Ring/FDDI)  Wait for your turn/have the token  Logical ring topology

77.  Ethernet’s collision detection system is known as what?  CSMA/CD  Describe CSMA/CD.  802.11 wireless networks use what for avoiding collisions?  CSMA/CA  What is the main difference between CSMA/CA & CD?  CA notifies all that you are sending

78. 4.4.4

82.  How is the FCS helpful in a frame?  Determines if there are errors  What is in the frame header?  Start frame & MAC addresses  The data in a frame can be how many bytes?  46-1500 bytes

83.  Complete the study guide handout  Take the quiz on netacad.com  Jeopardy review

84. In this chapter, you learned:  Devices

87. Chapter 4 Intro to Routing & Switching