IT Schweber Chap Questions, 30 Class Periods, 30 Answers It wasn’t unusual for a student to drop into my office,...but this student’s reason for dropping in was unique. The student began by saying, “I thought you would be interested in knowing how your class has helped me. I enjoyed studying the Book of Mormon, but I also had some problems I needed help with. So I came up with a plan. I wrote down a question for each class period. Then I prayed about the question and went to your...class.” The young man showed me the questions he had written down: 30 questions, 30 class periods, 30 answers. I noticed that many of the answers to his questions had nothing to do with the material I had been teaching! But this student had sought the Lord in prayer and had come in faith to my class, expecting the answers. And he had received an answer to every question! I realized that the Spirit had led him to find the answers to his questions. from Ralph E. Rigby Religion Instructor, BYU The Ensign, March 1999, p. 39

IT Schweber Chap 162

The Phone System Patented by Alexander Graham Bell in 1876 Means “far” (tele) “sound” (phone) Defined expectations for communication forever after 5-9’s reliability (up % of the time, or down only 1 hour out of 100,000). BTW, 100k Hrs ≈ 11 years Acceptable quality and understandability Digital voice defined by phone system

The Phone System: Origins Bell calling Chicago from New York (1892) Switchboard, c. 1890Phone, c. 1890

The Phone System: about 1930 Switchboard Operators, c. 1930

The Phone System: about 1930

The Phone System: about 1950 Central Office

The Phone System: about 1950

Leased, Conditioned, or Dedicated Lines (vs POTS)

DTMF

Features

Echo Cancellation