[Kamailio-Users] exchanging CDR data between Asterisk servers

Hi! I have the following setup: PSTN<------>Asterisk<-----SIP-->Asterisk GW/LCR \ \ ... \ \ ... \ --SIP-->Asterisk \ ... ------->Asterisk The GW-Asterisk just does the gatewaying stuff and writes the CDRs for the billing system. The other Asterisk servers handle all the services (IVR, REGISTER, ...) Some scenarios require to write some additional data to the CDRs. For outgoing calls this is not a problem (I signal the extra data in a SIP header and set a CDR() variable in the GW asterisk). My problem are incoming calls. The "extra data" is only known to the service Asterisk, but the CDR is written by the GW Asterisk. Does anybody know a method how to signal the "extra data" during the call from the server Asterisk back to the GW Asterisk und put it into a CDR() variable? Regards Klaus