1. © 2008 Cisco Systems, Inc. All rights reserved.Cisco ConfidentialPresentation_ID 1 Chapter 4: Network Access Introduction to Networks

2. Presentation_ID 2 © 2008 Cisco Systems, Inc. All rights reserved.Cisco Confidential Chapter 4: Objectives Students will be able to:  Explain how physical layer protocols and services support communications across data networks.  Build a simple network using the appropriate.  Explain the role of the data link layer in supporting communications across data networks.  Compare media access control techniques and logical topologies used in networks.

3. Presentation_ID 3 © 2008 Cisco Systems, Inc. All rights reserved.Cisco Confidential Chapter 4 4.1 Physical Layer Protocols 4.2 Network Media 4.3 Data Link Layer Protocols 4.4 Media Access Control 4.5 Summary

4. Presentation_ID 4 © 2008 Cisco Systems, Inc. All rights reserved.Cisco Confidential Getting it Connected Connecting to the Network

5. Presentation_ID 5 © 2008 Cisco Systems, Inc. All rights reserved.Cisco Confidential Getting it Connected Connecting to the Network

6. Presentation_ID 6 © 2008 Cisco Systems, Inc. All rights reserved.Cisco Confidential Getting it Connected Network Interface Cards Connecting to the Wireless LAN with a Range Extender

7. Presentation_ID 7 © 2008 Cisco Systems, Inc. All rights reserved.Cisco Confidential Purpose of the Physical Layer The Physical Layer

8. Presentation_ID 8 © 2008 Cisco Systems, Inc. All rights reserved.Cisco Confidential Purpose of the Physical Layer Physical Layer Media

9. Presentation_ID 9 © 2008 Cisco Systems, Inc. All rights reserved.Cisco Confidential Purpose of the Physical Layer Physical Layer Standards Standard organization Networking Standards ISO ISO 8877: Officially adopted the RJ connectors (e.g., RJ-11, RJ-45) ISO 11801: Network cabling standard similar to EIA/TIA 568. EIA/TIA TIA-568-C: Telecommunications cabling standards, used by nearly all voice, video and data networks. TIA-569-B: Commercial Building Standards for Telecommunications Pathways and Spaces TIA-598-C: Fiber optic color coding TIA-942: Telecommunications Infrastructure Standard for Data Centers ANSI 568-C: RJ-45 pinouts. Co-developed with EIA/TIA ITU-T G.992: ADSL IEEE 802.3: Ethernet 802.11: Wireless LAN (WLAN) & Mesh (Wi-Fi certification) 802.15: Bluetooth

10. Presentation_ID 10 © 2008 Cisco Systems, Inc. All rights reserved.Cisco Confidential Fundamental Principles of Layer 1 Physical Layer Fundamental Principles Media Physical Components Frame Encoding Technique Signalling Method Copper cable UTP Coaxial Connectors NICs Ports Interfaces Manchester Encoding Non-Return to Zero (NRZ) techniques 4B/5B codes are used with Multi-Level Transition Level 3 (MLT-3) signaling 8B/10B PAM5 Changes in the electromagnetic field Intensity of the electromagnetic field Phase of the electromagnetic wave Fiber Optic cable Single-mode Fiber Multimode Fiber Connectors NICs Interfaces Lasers and LEDs Photoreceptors Pulses of light Wavelength multiplexing using different colors A pulse equals 1. No pulse is 0. Wireless media Access Points NICs Radio Antennae DSSS (direct-sequence spread- spectrum) OFDM (orthogonal frequency division multiplexing) Radio waves

11. Presentation_ID 11 © 2008 Cisco Systems, Inc. All rights reserved.Cisco Confidential Fundamental Principles of Layer 1 Bandwidth

12. Presentation_ID 12 © 2008 Cisco Systems, Inc. All rights reserved.Cisco Confidential Fundamental Principles of Layer 1 Throughput

13. Presentation_ID 13 © 2008 Cisco Systems, Inc. All rights reserved.Cisco Confidential Fundamental Principles of Layer 1 Types of Physical Media

14. Presentation_ID 14 © 2008 Cisco Systems, Inc. All rights reserved.Cisco Confidential Network Media Copper Cabling

15. Presentation_ID 15 © 2008 Cisco Systems, Inc. All rights reserved.Cisco Confidential Copper Cabling Characteristics of Copper Media

16. Presentation_ID 16 © 2008 Cisco Systems, Inc. All rights reserved.Cisco Confidential Copper Cabling Copper Media Shielded Twisted Pair (STP) cableUnshielded Twisted Pair (UTP) cable Coaxial cable

17. Presentation_ID 17 © 2008 Cisco Systems, Inc. All rights reserved.Cisco Confidential Copper Cabling Unshielded Twisted-Pair (UTP) Cable

18. Presentation_ID 18 © 2008 Cisco Systems, Inc. All rights reserved.Cisco Confidential Copper Cabling Shielded Twisted-Pair (STP) Cable Foil Shields Braided or Foil Shield

19. Presentation_ID 19 © 2008 Cisco Systems, Inc. All rights reserved.Cisco Confidential Copper Cabling Coaxial Cable

20. Presentation_ID 20 © 2008 Cisco Systems, Inc. All rights reserved.Cisco Confidential Copper Cabling Cooper Media Safety

21. Presentation_ID 21 © 2008 Cisco Systems, Inc. All rights reserved.Cisco Confidential UTP Cabling Properties of UTP Cabling

22. Presentation_ID 22 © 2008 Cisco Systems, Inc. All rights reserved.Cisco Confidential UTP Cabling UTP Cabling Standards

23. Presentation_ID 23 © 2008 Cisco Systems, Inc. All rights reserved.Cisco Confidential UTP Cabling UTP Connectors

24. Presentation_ID 24 © 2008 Cisco Systems, Inc. All rights reserved.Cisco Confidential UTP Cabling Types of UTP Cable

25. Presentation_ID 25 © 2008 Cisco Systems, Inc. All rights reserved.Cisco Confidential UTP Cabling Testing UTP Cables

26. Presentation_ID 26 © 2008 Cisco Systems, Inc. All rights reserved.Cisco Confidential UTP Cabling Testing UTP Cables

27. Presentation_ID 27 © 2008 Cisco Systems, Inc. All rights reserved.Cisco Confidential Fiber Optic Cabling Properties of Fiber Optic Cabling

28. Presentation_ID 28 © 2008 Cisco Systems, Inc. All rights reserved.Cisco Confidential Fiber Optic Cabling Fiber Media Cable Design

29. Presentation_ID 29 © 2008 Cisco Systems, Inc. All rights reserved.Cisco Confidential Fiber Optic Cabling Types of Fiber Media

30. Presentation_ID 30 © 2008 Cisco Systems, Inc. All rights reserved.Cisco Confidential Fiber Optic Cabling Network Fiber Connectors

31. Presentation_ID 31 © 2008 Cisco Systems, Inc. All rights reserved.Cisco Confidential Fiber Optic Cabling Testing Fiber Cables

32. Presentation_ID 32 © 2008 Cisco Systems, Inc. All rights reserved.Cisco Confidential Fiber Optic Cabling Fiber versus Copper Implementation issuesCopper mediaFibre-optic Bandwidth supported 10 Mbps – 10 Gbps10 Mbps – 100 Gbps Distance Relatively short (1 – 100 meters) Relatively High (1 – 100,000 meters) Immunity to EMI and RFI Low High (Completely immune) Immunity to electrical hazards Low High (Completely immune) Media and connector costs LowestHighest Installation skills required LowestHighest Safety precautions LowestHighest

33. Presentation_ID 33 © 2008 Cisco Systems, Inc. All rights reserved.Cisco Confidential Wireless Media Properties of Wireless Media

34. Presentation_ID 34 © 2008 Cisco Systems, Inc. All rights reserved.Cisco Confidential IEEE 802.11 standards Commonly referred to as Wi-Fi. Uses CSMA/CA Variations include: 802.11a: 54 Mbps, 5 GHz 802.11b: 11 Mbps, 2.4 GHz 802.11g: 54 Mbps, 2.4 GHz 802.11n: 600 Mbps, 2.4 and 5 GHz 802.11ac: 1 Gbps, 5 GHz 802.11ad: 7 Gbps, 2.4 GHz, 5 GHz, and 60 GHz IEEE 802.15 standard Supports speeds up to 3 Mbps Provides device pairing over distances from 1 to 100 meters. IEEE 802.16 standard Provides speeds up to 1 Gbps Uses a point-to-multipoint topology to provide wireless broadband access. Wireless Media Types of Wireless Media

35. Presentation_ID 35 © 2008 Cisco Systems, Inc. All rights reserved.Cisco Confidential Wireless Media Wireless LAN Cisco Linksys EA6500 802.11ac wireless router

36. Presentation_ID 36 © 2008 Cisco Systems, Inc. All rights reserved.Cisco Confidential Wireless Media 802.11 Wi-Fi Standards 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 GHz 802.11b/g/n 802.11ad 7 Gbps (7000 Mbps) 2.4 GHz, 5 GHz and 60 GHz 802.11b/g/n/ac

37. Presentation_ID 37 © 2008 Cisco Systems, Inc. All rights reserved.Cisco Confidential Purpose of the Data Link Layer The Data Link Layer

38. Presentation_ID 38 © 2008 Cisco Systems, Inc. All rights reserved.Cisco Confidential Purpose of the Data Link Layer Data Link Sublayers Network Data Link LLC Sublayer MAC Sublayer Physical 802.3 Ethernet 802.3 Ethernet 802.11 Wi-Fi 802.11 Wi-Fi 802.15 Bluetooth 802.15 Bluetooth

39. Presentation_ID 39 © 2008 Cisco Systems, Inc. All rights reserved.Cisco Confidential Purpose of the Data Link Layer Media Access Control

40. Presentation_ID 40 © 2008 Cisco Systems, Inc. All rights reserved.Cisco Confidential Purpose of the Data Link Layer Providing Access to Media

41. Presentation_ID 41 © 2008 Cisco Systems, Inc. All rights reserved.Cisco Confidential Data Link Layer Layer 2 Frame Structure

42. Presentation_ID 42 © 2008 Cisco Systems, Inc. All rights reserved.Cisco Confidential Layer 2 Frame Structure Creating a Frame

43. Presentation_ID 43 © 2008 Cisco Systems, Inc. All rights reserved.Cisco Confidential Data Link Layer Layer 2 Standards

44. Presentation_ID 44 © 2008 Cisco Systems, Inc. All rights reserved.Cisco Confidential Layer 2 Standards Data Link Layer Standards Standard organization Networking Standards IEEE 802.2: Logical Link Control (LLC) 802.3: Ethernet 802.4: Token bus 802.5: Token passing 802.11: Wireless LAN (WLAN) & Mesh (Wi-Fi certification) 802.15: Bluetooth 802.16: WiMax ITU-T G.992: ADSL G.8100 - G.8199: MPLS over Transport aspects Q.921: ISDN Q.922: Frame Relay ISO HDLC (High Level Data Link Control) ISO 9314: FDDI Media Access Control (MAC) ANSI X3T9.5 and X3T12: Fiber Distributed Data Interface (FDDI)

45. Presentation_ID 45 © 2008 Cisco Systems, Inc. All rights reserved.Cisco Confidential Topologies Controlling Access to the Media

46. Presentation_ID 46 © 2008 Cisco Systems, Inc. All rights reserved.Cisco Confidential Topologies Physical and Logical Topologies

47. Presentation_ID 47 © 2008 Cisco Systems, Inc. All rights reserved.Cisco Confidential WAN Topologies Common Physical WAN Topologies

48. Presentation_ID 48 © 2008 Cisco Systems, Inc. All rights reserved.Cisco Confidential WAN Topologies Physical Point-to-Point Topology

49. Presentation_ID 49 © 2008 Cisco Systems, Inc. All rights reserved.Cisco Confidential WAN Topologies Logical Point-to-Point Topology

50. Presentation_ID 50 © 2008 Cisco Systems, Inc. All rights reserved.Cisco Confidential WAN Topologies Half and Full Duplex

51. Presentation_ID 51 © 2008 Cisco Systems, Inc. All rights reserved.Cisco Confidential LAN Topologies Physical LAN Topologies

52. Presentation_ID 52 © 2008 Cisco Systems, Inc. All rights reserved.Cisco Confidential LAN Topologies Logical Topology for Shared Media

53. Presentation_ID 53 © 2008 Cisco Systems, Inc. All rights reserved.Cisco Confidential LAN Topologies Contention-Based Access CharacteristicsContention-Based Technologies Stations can transmit at any time Collision exist There are mechanisms to resolve contention for the media CSMA/CD for 802.3 Ethernet networks CSMA/CA for 802.11 wireless networks

54. Presentation_ID 54 © 2008 Cisco Systems, Inc. All rights reserved.Cisco Confidential LAN Topologies Multi-Access Topology

55. Presentation_ID 55 © 2008 Cisco Systems, Inc. All rights reserved.Cisco Confidential LAN Topologies Controlled Access CharacteristicsControlled Access Technologies Only one station can transmit at a time Devices wishing to transmit must wait their turn No collisions May use a token passing method Token Ring (IEEE 802.5) Fiber Distributed Data Interface (FDDI)

56. Presentation_ID 56 © 2008 Cisco Systems, Inc. All rights reserved.Cisco Confidential LAN Topologies Ring Topology

57. Presentation_ID 57 © 2008 Cisco Systems, Inc. All rights reserved.Cisco Confidential Data Link Frame The Frame

58. Presentation_ID 58 © 2008 Cisco Systems, Inc. All rights reserved.Cisco Confidential Data Link Frame The Header

59. Presentation_ID 59 © 2008 Cisco Systems, Inc. All rights reserved.Cisco Confidential Data Link Frame Layer 2 Address

60. Presentation_ID 60 © 2008 Cisco Systems, Inc. All rights reserved.Cisco Confidential Data Link Frame The Trailer

61. Presentation_ID 61 © 2008 Cisco Systems, Inc. All rights reserved.Cisco Confidential Data Link Frame LAN and WAN Frames

62. Presentation_ID 62 © 2008 Cisco Systems, Inc. All rights reserved.Cisco Confidential Data Link Frame Ethernet Frame

63. Presentation_ID 63 © 2008 Cisco Systems, Inc. All rights reserved.Cisco Confidential Data Link Frame Point-to-Point Protocol Frame

64. Presentation_ID 64 © 2008 Cisco Systems, Inc. All rights reserved.Cisco Confidential Data Link Frame 802.11 Wireless Frame

65. Presentation_ID 65 © 2008 Cisco Systems, Inc. All rights reserved.Cisco Confidential Network Access Summary Physical Layer Protocols Network Media Data Link Layer Protocols Media Access Control

66. Presentation_ID 66 © 2008 Cisco Systems, Inc. All rights reserved.Cisco Confidential