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
VoiceIP-USA Incorporation a company incorporated in USA ,whose registered address is World Trade Centre Delaware, 802 West Street, Suite 105, Wilmington, Delaware 19801