About some good solutions in classic telephone techniques
Žarko Markov, Aleksandar Lebl, Dragan Mitić · Tehnika · 2012
Four characteristics are compared in modern (IP and mobile) telephone networks and in classic (analog, digital and ISDN) telephone networks. These characteristics are: bitrate of speech signal, inband signaling, loss of speech information and variable speech signal quality. It is shown that these features are better in classic telephone networks than in modern networks, especially regarding the loss of speech information.