Internet telephony using regular telephone sets is implemented through gateways that interface between the public-switched telephone network and the Internet. Gateways receive incoming calls over the public telephone network, digitize and compress the voice transmissions into electronic data packets. These digitized data packets are then sent over the Internet to a destination gateway, which converts the call to its original analog format and sends it out to the public telephone network for call termination.

THE INTERNET TELEPHONY PROCESS

A Network Operations Center (NOC) monitors the operations and provides real-time, real-traffic network management information. In addition, the NOC houses the main gatekeepers, which help the function of routing packets from the origination gateway to the termination gateway, as well as the billing and network management systems.

All network elements are monitored 24 hours per day, seven days per week, and alarms are activated when a failure is detected. Performance and availability data are constantly updated allowing for exception handling, including re-routing to private IP networks and alternate use of the PSTN, if necessary. Stability and availability of gateways, gatekeepers and routers, quality of the Internet and PSTN links, and call detail record analysis in order to assess the call-completion rate are all functions performed by the Globalnova NOC's in Brazil and USA. NOC engineers are always on-duty to promptly restore service and minimize, as much as possible, network downtime.