Applying different codecs in a VoIP system in a calling state and in a call connecting state

摘要

A system and method to change codec information to provide a coloring ring back service in a Voice over Internet Protocol (VoIP) terminal uses different compression methods (codecs) depending on a calling state and a call connecting state between the VoIP terminals so that a more efficient coloring service is provided. The system for changing codec information includes a gateway adapted to compress ring back tone data in a calling state and to compress voice signal data in a call connecting state between communication terminals according to preset different compression information and to transmit both data to a receiving terminal.