Today, almost everything depends upon the Mobility. The fascination of mobility, accessibility and flexibility makes wireless technologies the dominant method of transferring all sorts of information. Satellite televisions, cellular phones and wireless Internet are well-known applications of wireless technologies. As in VANETs, the vehicles (Mobile nodes) communicate among each other while moving. They impart information about the warning alerts to the other vehicles in the network about the hazards when it happens and helps to reduce the accidents. The facility of free voice calling can also be provided to the moving vehicles using VoIP application. To realize the importance of voice calling, this book is focusing especially on various Voice CODECs. It is based on inter-vehicle communication over VANET. For this task, various voice CODECs behaviour was tested and analyzed the impact of varying traffic condition on the performance of QoS of VoIP.The analysis should help shed some light on this new and exciting networking environment, and should be especially useful to professionals in this field, or anyone else who may be considering utilizing voice calling in VANETs.