Charging method and charging system based on SIP message body

The invention relates to a charging method and a charging system based on an SIP message body. According to the charging method and the charging system, application/charging information defined by the invention can be carried in an SIP INFO message after an SIP dialogue is established or in a 183 dialogue procedure before the SIP dialogue is established to realize the new and integral process and the system during the message interactive conversion of SIP and ISUP charging information. In addition, the invention also provides an SIP charging method and an SIP charging system when an SIP proxy server plays a role needing to confirm a charging rate and transferring the charging rate to a charging confirmation point of a charging generating point for processing charging.