ABSTRACT
Skype is a well-known free voice over IP service that has picked up millions of users within the last few years. Unlike many of its competitors, it has achieved almost household name status. Machines with more powerful CPUs, more memory, and more network bandwidth are also preferred. Skype uses the public Internet as its transport medium. Unlike traditional carriers, it sees the whole world as its marketplace, and this has been reflected in its rapid growth. Skype transmits voice frequencies between 50 Hz and 8 kHz, twice the bandwidth of ordinary Public Switched Telephone Network calls, and the improved quality is quite noticeable over even a low-rate broadband connection. Skype’s cost base is a log-in server cluster, perhaps a few PC bootstrap super nodes, and the salaries and expenses of its few executives and programmers. The operational infrastructure for the millions of Skype users consists of their already existing computers and broadband Internet connections.
