Concerning practical implementation, the VoIP gateways have proven to be the best. Many companies are successfully using the IP telephony thanks to its two main characteristics
Decrease in international and long distance call cost expenditures
Stable communications between company’s offices throughout different cities and counties
IceHook provides modular, cloud based applications to telecom service providers that: manage rates, automate the offsite storage of CDR''s, and provide near real time routing analysis.