[Freeswitch-users] passing originating IP when configured as a B2BUA

Hello list, we have an FS server configured as a call-distributor (using "mod_distributor") to a bank/farm of Asterisk servers. However, since the FS is acting like a B2BUA, it's not passing the originating IP (network_addr) from the originating switch/gateway to the Asterisk farm (as expected). However, we need to have this information in the Asterisk servers. How can we achieve this? Do we need to create/insert a custom SIP header when passing on the call or set a variable or any other way? Any help on the issue will be much appreciated Thanks in advance, RR