SIP Demystified.Signalling in the Circuit-Switched Network

Аннотация

The telephone network, also known as the Public Switched Telephone Network (PSTN), reaches almost every country in the world. We can find telephone sets almost in every house, including simple analog phones, more advanced Integrated Services Digital Network (ISDN) phones, cordless phones, cellular phones, and even satellite phones. Among technologies, telephone systems are astonishingly widespread.