Background Noise Influence on VoIP Traffic Profile
Modern audio codecs used in VoIP can improve the listening quality by transmitting the main characteristics of the background noise signal during the silence periods. This traffic has been traditionally neglected in the codec mean bit-rate estimation. Nevertheless, when considering an IP environment, the packet overhead increases significantly the required mean transmission bit-rate. Hence, the transmission of the background noise signal can result into either a poor network resource dimensioning in network planning or in the violation of the SLA traffic specifications in a DiffServ scenario.
Based on the study of SIP,the paper presents the overlay method to implement the mapping between SIP protocol state machine and IN call state model BCSM,and analyses the implementation concretely.The method has resolved the key technology in interworking of Internet and IN.