1. Principles of Voice & Data Lesson 1: Telephony Essentials Bellevue Community College Bob Young, Instructor

2. Terms & Explanations PSTN Public Switched Telephone Network

3. Terms & Explanations POTS "Plain Old Telephone Service" as in, "POTS line."

4. Terms & Explanations Phone Parts Transmitter - Mouthpiece Receiver - Earpiece

5. Terms & Explanations Full Duplex - voice can be sent in both directions at the same time. Half Duplex - voice can be sent in one direction at a time.

6. Terms & Explanations C.O. or CO Central Office

7. Terms & Explanations CPE Customer Premise Equipment CPE may be owned by the telco or by the customer

8. Terms & Explanations The "Last Mile" From the CO to the CPE

9. Terms & Explanations Outside Plant Telco equipment between the CO and the customer Poles, lines, vaults, etc.

10. Terms & Explanations On Hook The phone's handset is in the cradle. Open loop condition - no loop current.

11. Terms & Explanations Off Hook The phone's handset is out of the cradle. Closed loop condition - loop current is present.

12. Terms & Explanations RBOC Regional Bell Operating Company 1984 - Divestiture of AT&T Formation of 7 RBOC's

13. The Seven RBOCS: 1)Ameritech 2)Bell Atlantic 3)BellSouth 4)NYNEX 5)Pacific Bell 6)Southwestern Bell 7)US WEST

14. RBOC Map, 1984

15. Terms & Explanations BOC Bell Operating Company Smaller, regional companies within the RBOC's – (22 BOC's)

16. Terms & Explanations IXC Interexchange Carrier After divestiture, IXC's handled long distance calls

17. Terms & Explanations LEC Local Exchange Carrier

18. Terms & Explanations LATA Local Access and Transport Area

19. Terms & Explanations ILEC Incumbent Local Exchange Carrier

20. Terms & Explanations CLEC Competing (or Competitive) Local Exchange Carrier

21. Terms & Explanations British Terms GPO - General Post Office BPO - British Post Office BT - British Telecom

22. Terms & Explanations ITU International Telecommunications Union

23. Terms & Explanations ITU-T International Telecommunications Union - Telecommunications Standardization Sector

24. Terms & Explanations Tandem Office A central office unit used primarily as an intermediate switching point for traffic between local central offices within the tandem area

25. Terms & Explanations Toll Tandem A central office unit used as the switching point between local CO traffic and toll (long distance) traffic

26. Terms & Explanations EO End Office A Central Office that connects directly to subscribers

27. Terms & Explanations Switches - Class 5 An End Office switch Provides local loop connections Call signaling and control - setup and knockdown

28. Terms & Explanations Switches - Class 4 A tandem switch Capable of connecting Class 5 switches

29. Terms & Explanations Switches - Class 3 A toll traffic switch Connects LEC's Capable of connecting Class 4 & 5 switches

30. Terms & Explanations PCM Pulse Code Modulation   -law (North America & Japan)  A-law (all other countries)  8 KHz sampling rate

31. Terms & Explanations PCM Issues Unrepresentative Sample Lack of Information Too Much Information

32. Terms & Explanations POP, PoP Point of Presence POI Point of Interconnection

33. Terms & Explanations FX Foreign Exchange FXO - Foreign Exchange Office FXS - Foreign Exchange Station

34. Terms & Explanations PBX Private Branch Exchange

35. Terms & Explanations KSU Key Service Unit or Key Switching Unit

36. Terms & Explanations DID Direct Inward Dialing as in, "DID Trunk"

37. Terms & Explanations DOD Direct Outward Dialing as in, "DOD Trunk"

38. Terms & Explanations Centrex Service A telco service in which the PBX hardware and functionality is provided and maintained by the telco

39. Terms & Explanations Analog Loop Start The call is originated by going off hook. Loop current initiates the call sequence.

40. Terms & Explanations E & M Trunks Voice and signaling are carried on separate wires E = "Ear" M = "Mouth"

41. Terms & Explanations Ground-Start Trunks The call sequence is initiated by grounding either the tip (from CO) or the ring wire (from PBX)

42. Terms & Explanations DSH Digital Signal Hierarchy DS0, DS1, DS3 T1, T3 T1 = 1.544 Mbps

43. Terms & Explanations SF & ESF Super Frame (D4) Extended Super Frame

44. Terms & Explanations E-Carrier Europe uses E1's instead of T1's E1 = 2.048 Mbps

45. Terms & Explanations SONET Synchronous Optical Network North American Standard Compare with SDH STS-1 = 51.84 Mbps

46. Terms & Explanations STS & OC Synchronous Transport Signal Optical Carrier Exact same data rates Know both terms

47. Terms & Explanations STS-1 = OC-1 = 51.84 Mbps STS-2 = OC-2 = 103.68 Mbps STS-3 = OC-3 = 155.52 Mbps etc.

48. SONET Physical Hierarchy

49. SONET Architecture

50. SONET Ring

51. Terms & Explanations SONET & OSI Model OSI Layer 1 Standard (Physical Layer)

52. Terms & Explanations More SONET Info SONET can be used for: ATM Gigabit Ethernet

53. Terms & Explanations SDH Synchronous Digital Hierarchy International Standard Don't confuse with DSH STM-1 = 155.52 Mbps

54. Terms & Explanations 155.52 Mbps STS-3 OC-3 STM-1

55. Terms & Explanations A & B Bit Signaling Digital equivalent of analog line signals Status of bits indicates idle or busy (on-hook, off-hook)

56. Stratum Clocks

57. Terms & Explanations Types of Timing Asynchronous Synchronous Plesiosynchronous

58. Terms & Explanations CSU/DSU Channel Service Unit Data Service Unit

59. Terms & Explanations SWC, WC Service Wire Center Wire Center

60. Terms & Explanations Distribution Frame Permanent wiring set up for easy cross connection

61. Terms & Explanations MDF Main Distribution Frame Typically at CO or large PBX

62. Terms & Explanations IDF Intermediate Distribution Frame Typically outside plant or customer premise

63. Terms & Explanations CDF Combined Distribution Frame Vertical blocks - CO lines Horizontal blocks - inside lines

64. Terms & Explanations MPOE Minimum Point of Entry Demarcation Point (Demarc)

65. Terms & Explanations NID Network Interface Device

66. Terms & Explanations Load Coils Reduces line loss Matches impedance Analog circuits only - Can't use in digital circuits

67. Terms & Explanations Bridge Tap Allows a cable to be run to more than one location Each circuit can only be used at one location

68. Terms & Explanations Call Processing Call setup Call maintenance Call completion (knockdown)

69. Call Signaling Dial tone - 350 Hz and 440 Hz at –12 dBm Pulse dialing - (10 pps standard) 40msec make, 60msec break, 600msec pause DTMF - (23 pps standard) Ring - (80-90 VAC at 20 Hz) Ringback - 440 Hz and 480 Hz at –20dBm, 0.2 sec on, 0.4 sec off Busy - 480 Hz and 620 Hz, 0.5 sec on, 0.5 sec off

70. Analog Problems Loss Echo Noise Crosstalk Delay

71. Terms & Explanations Echo Cancellation Acoustic Echo Control (wireless networks) Far End Echo Cancellation (long distance, satellite)