Telefoonivõrkudes
Telefoonivõrkudes are telephone networks. These networks are a system of interconnected telephones, switching centers, and transmission lines that enable voice communication between users. Historically, telephone networks evolved from simple manual switchboards connecting a few individuals to complex, automated systems capable of handling millions of calls simultaneously. Modern telephone networks can be broadly categorized into public switched telephone networks (PSTN) and private branch exchanges (PBX). PSTNs are the vast, interconnected infrastructure used by the general public, allowing calls to be made to virtually any other phone number globally. PBXs are smaller, private systems often used by businesses to manage internal calls and provide external lines.
The technology behind telephone networks has undergone significant transformation. Early systems relied on analog signals transmitted