[Freeswitch-users] Route calls based on the Nb they are divert by

Hi everyone I was wondering if it is possible route calls based on the numbers they were divert by, perhaps using "sip_redirected_by". Let's assume I own two phone numbers of my old fixed telephone lines and one VoIP Account/Number. If I redirect the two fixnet numbers to the same VoIP number, is it possible to "demultiplex" the incoming calls based on the number they were redirected by? I am not sure about the available meta data provided by SIP, however I am certain that my ISDN phone is sometimes showing "xxxx is calling, redirected by yyyyy" Best Wishes Andreas