Cell Phone Etiquette

1. Cell Phone Etiquette Please Turn Off All Cell Phones

2. Module 1 - Lesson 1 Local Exchange Components PAC Bell NOC • Class Reminders • Complete5 Activities, Starting • On Page 30. • Due Date – August 23, 2005 Class Thought No Question Is A Bad Question!

3. Design & Implementation of Voice Networks This lesson presents an overview of the structure of the telephone system, and introduces the elements of a typical local telephone exchange. • At the end of Lesson 1, you should be able to: • Describe The Telephone System Hierarchy • Explain What A CO Switch Is And What It Does • Describe The Purpose Of A Tandem CO Switch • Explain The Relationship Of The Customer Premise To The Public Telephone Network

4. Design & Implementation of Voice Networks The Original Telephone Hierarchy • The Public-Switched Telephone Network (PSTN) Is Organized As A Multilevel Hierarchy. • The Original Telephone System Used Five Numbered Levels, As Shown On The Original Telecommunications Hierarchy Diagram. Original Telecommunications Hierarchy

5. The Current Telephone Hierarchy • The Class 5 Offices, Or End Offices, Connect To Individual Subscribers, As Shown On The Current Telecommunications Hierarchy Diagram.

6. Class 5 Central Office: The Local Exchange • The Class 5 CO Is Also Called The End Office Or Local Office. • It Is The Local Workhorse For The Telephone And Data Communications Traffic In One Local Exchange.

7. All Customers Connect To Class 5 Central Offices - Businesses Class 5 Central Office Digital Local Loop T1 Demarc CSU Video PBX Digital/Data Analog/Voice Digital/Voice

8. CSUs – Federal Requirements • The Federal Communications Commission’s (FCC) • Part 68 Registration Rules For T-Carrier Circuits • Requires That Every T-Carrier Circuit Be • Terminated By A Channel Service Unit. Central Office Customer Premises Digital Transmission Media Channel Bank T1 Multiplexer Digital Cross Connect PBX Channel Bank T1 Multiplexer Digital Cross Connect PBX CSU CSU Copper Fiber or Microwave • CSUs Terminate Each End Of The T-Carrier.

9. CSUs – Key Functions • Channel Service Units Perform The Following • Functions: • Line Build Out (LBO) – LBO Simulates A Length • Of Wire Line That Adjusts The Line Signal Power • Before The Signal Is Sent Out Into The Network So • That The Signal Level Falls Within A Certain • Decibel Range. • Minimizes Crosstalk - By Controlling The Signal • Level On The T1 Transmitter-Pair, Thereby, • Minimizing The Possibility Of Cross Talk To A • Receiver-Pair In The Same Binder.

10. CSUs – Key Functions - Continued • Repeater Functionality – The Repeater Functionality • Adjusts Signals For Power Loss And Distortions • Caused By In-House Wiring. • CSUs Also Ensures That The User’s DTE Does Not • Send Signals That Could Possibly Disrupt The • Carrier’s Network. • For Example, Long Strings Of Zeros Do Not • Provide Timing Pulses In Order For The Span- • Line Repeaters To Maintain Synchronization. • The CSU Monitors The Data Stream From The • DTE So That The Ones Density Rule Is Not • Violated.

11. CSUs – Key Functions - Continued • Proactive Network Management - The CSUs Provide • Functionality To Troubleshoot Circuits And • Transmission Problems. • LEDs That Indicate The Status Of Both The • Network And Equipment Connections. • Monitors Alarm Thresholds Or Error Conditions. • Contains A Buffer That Stores Collected • Performance Information That Can Be Accessed • By The Customer And Carrier Technicians. • Provides The Ability For Remote Loopback Testing.

12. CSUs – Key Functions - Continued • Isolation – The CSU Also Provides Isolation Between • The DTE And The Network, In Order To Protect • Equipment Technicians From Harmful Line Voltages • And Lightning Surges.

13. All Customers Connect To Class 5 Central Offices - Residences Class 5 Central Office Analog Local Loop Demarc What kind of jack? Analog/Data Analog/Voice

14. Computer Communications - Analog PC Operations Serial Modem A/D Bytes Analog UART Bits • Answer the questions on the next Vu Graph as a part of your assignment for this lesson.

15. Computer Communications - Analog • Assignment Question 6: • Define a UART – What does the acronym stand for? • Explain the following functionalities – (1) Parallel-To Serial vis-a-vie Inbound/Outbound transmission, (2) Parity bit vis-a-vie Inbound/Outbound transmission, (3) Start/stop bits vis-a-vie Inbound/Outbound transmission, and (4) Interrupts.

16. Class 5 Central Office: The Local Exchange • If A Subscriber Places A Call To Another Subscriber Connected To The Same Class 5 Office, That Office Makes The Connection Directly, As Shown On The Call Within The Same Exchange Diagram. Call Within the Same Exchange

17. Local Calls • The Local Switching System General Requirements • (LSSGR) Contains All Requirements For Connecting CPE • To The Local Class 5 Switch. • Examples Of LSSGR Defined Supervisory Signals.

18. Local Calls • Study The Local-Call State Diagram Sheet

19. Class 5 Central Office: The Local Exchange • If The Caller’s Class 5 CO Is Directly Connected To The Destination Class 5 CO, The Calling CO Passes The Call Directly To The Destination CO, Which Completes The Call To The Destination Subscriber, As Shown On The Calling Handoff Diagram. Calling Handoff

20. Class 5 Central Office: The Local Exchange • If The Destination CO Is Not Directly Connected To The Calling CO, Or If That Connection Is Too Busy, The Caller’s Class 5 CO Passes The Call Up The Hierarchy To Its Parent Class 4 Office, As Shown On The Tandem Switching Diagram. Tandem Switching

21. Class 4 Central Office • Each Class 4 CO Connects To Multiple Class 5 Offices. Each Class 4 Office Also Connects To Nearby Class 4 Offices As Well As Its Parent Class 1 Office. • This Interconnection Provides Alternate Paths For Calls In The Event Of A Cable Outage Or, More Commonly, Congestion On The Network.

22. Tandem Central Offices • The Number Of Connections Becomes Unmanageable As The Number Of Offices Grows, As Shown On The Direct Connections Diagram. Direct Connections

23. Tandem Central Offices • As You Can See From The Switching Hierarchy Diagram, Six Direct Connections Are Needed To Link Four Offices; Each Office Also Needs A Separate Connection To Its Parent Class 4 Office. Switch Hierarchy

24. Tandem Central Offices • Toll Tandem Offices, Also Called InterExchange Tandem Offices, Connect Class 5 COs To The Class 4 Offices Of The IXCs. • As You Can See On The Tandem Central Offices Diagram, Tandem Offices Provide A More Efficient Way To Connect Multiple Class 5 COs To One Another And InterExchange Carrier Switches.

25. Tandem Central Offices Tandem Central Offices

26. Class 1 Offices • Class 1 Offices, Or Regional Toll Telephone Offices, Formed The Backbone Of The Telecommunications System And Appear In Only A Few Places In The Country. • A Class 1 Office Is Also Known As An “Office Of Last Resort.”

27. Class 5 Central Office Components • A Class 5 CO May Be Called Many Things Including: • The CO • Serving CO • End Office • Local Exchange Carrier (LEC) CO • LEC Switch • CO Switch • Switch

28. Class 5 Central Office Components • A Single CO Serves A Roughly Circular Geographic Area, Called A “Wire Center.” • Each Pair Of Wires That Connects A Single Telephone To The Co Is Called A “Local Loop.” • Each CO Building Contains: • A CO Switching System • Backup Power Systems • Connections To Other COs • Administrative Offices

29. Class 5 Central Office Components • Multiple Computers And Associated Electronic Equipment Perform The Following Key Functions Of A Class 5 CO: • Switching And Routing Calls • Semipermanent Circuit Connections • IXC Point Of Presence (POP) • Billing

30. Switching and Routing • The Main Objective Of A CO Telecommunications System Is To Create Temporary Connections Between Thousands Of Pairs Of Users.

31. Semipermanent Circuit Connections • A DACS Establishes A Semipermanent Path For Voice Or Data Signals. • This Path Is Created By A Programmed Order Or Administrative Action, Known As “Provisioning.” • Once Created, A Path (Private Line) Remains Connected Until It Is Disconnected Or Changed, As Shown On The Digital Access Cross-Connect System Diagram.

32. Semipermanent Circuit Connections Digital Access Cross-Connect System

33. Semipermanent Circuit Connections • The DACS Eliminates Most Of The Labor Associated With Wire Rearrangement. • This System Eliminates Extra Analog-To-Digital Conversions, And Offers A High Degree Of Flexibility In Rerouting Circuits.

34. IXC Point of Presence (POP) • The Handoff Point Between The LEC And IXC Is Called The Carrier’s POP. • A POP Is A CO Switch. • An IXC POP Is Located In The Same Building As The LEC CO Known As A CO-Location.

35. Billing • Billing Is A Critical CO Function. • The CO Switch Creates A Call Detail Report (CDR) That Itemizes Each Call And Its Duration.

36. Customer Premises • The Telephone Hierarchy Branches Outward Like A Tree, From The Main Trunks Of The IXCs To The Small Branches Of Each Local Exchange. • The “Leaves” Of Each Branch Are Formed By Individual Telephone Customers, Located At Each “Customer Premises.” • Customer-provided Equipment, Or Customer Premises Equipment (CPE), Originally Referred To Equipment On A Customer Premises That Was Purchased From A Vendor Other Than The Local Telephone Company.

37. Local Exchange Calling Options • Some Of The Ways Service Can Be Provided Within A Local Exchange: • Local Exchange Carrier (LEC) Does It All • Competitive Local Exchange Carrier (CLEC) Serves As Reseller • CLECs Switch And ILECs Wire • CLEC Does It All

38. Local Exchange Carrier (LEC) Does It All • In The Simplest Case, An ILEC (Probably An RBOC) Provides All Local Service. This Was The Situation Before The Introduction Of Competition. • The Customer Is Connected To The LEC Co. • The Customer Is Billed By The LEC. • The LEC Provides All Services.

39. Competitive Local Exchange Carrier (CLEC) Serves as Reseller • In This Option, A CLEC Merely Resells A LEC’s Services. The CLEC Bills Its Customers, Or Has The LEC Print Special Bills For The CLEC. The CLEC Provides Customer Sales And Support. • The Customer’s Telephone Is Still Connected To LEC Co. • The LEC Bills The CLEC, And The CLEC Bills The Customer. • The CLEC Provides One-Stop Shopping: Sales, Support, And Billing. • The CLEC Coordinates Services Through The LEC.

40. CLECs Switch and ILECs Wire • A CLEC Has Its Own Class 5 CO Switch. • The Unbundled Local Loop Diagram Shows The CLEC Provides Switching To The Call Destination And Provides Sales/Support/Billing And Other Services To The Customer. Unbundled Local Loop

41. CLEC Does It All • A CLEC Can Also Provide End-To-End Local Service, By Providing All Of Its Own Switches And Loops. • A CLEC That Provides Complete Local Service Still Must Rely On The Services Of An IXC And Distant LEC Or CLEC To Process Many Calls.