A cooperative SIP infrastructure for highly reliable telecommunication services

Voice over IP (VoIP) has been a promising technology for several years. Although it has become very popular, the vision to substitute the "good old" Public Switched Telephone Network (PSTN) is still far from being true. Several issues, such as security, reliability and emergency calls are slowing down the integration of VoIP. Currently, there is a mixture of technologies where VoIP is often used for reducing costs, while still keeping the PSTN...