... Telecommunications, Winter 2000 Lecture-25 Telephone System The Telephone System: (Ref: Ch-4, Page-113 of your Text book) The telephone system remains as the backbone of low-cost telecommunications ... connected to a class 2 etc. The telephone system was originally designed as an analog system, but today, most trunk lines are digital. Lecture25 .doc Page 3 (6) CSN200 Introduction to Telecommunications, ... Pulse Dial Tone dialLecture25 .doc Page 2 (6) CSN200 Introduction to Telecommunications, Winter 2000 Lecture-25 Telephone System Telephone Switching Facilities: • Switching...