Abstract :
Invented over 100 years ago, the telephone is perhaps the most widely used form of long distance communication invented. Yet few people have more than even the foggiest notion of how it actually works. The main purpose of this report is to describe how the call is actually placed after the caller enters the telephone number. The paper will describe how a call is routed, how multiple calls can be placed on the same telephone line, and the types of telephone switches used today and in the past
