[Serusers] SER and B2BUA

Hello all, It seems many new comers like me have got problems configuring these two together. I haven't found any information in the list. The scenario is that I want to put B2bua(vovida) in line for a prepaid system. SER should route calls to B2BUA which will be eventually return back to SER to be routed to the final destination. The problem is how to configure SER to prevent routing loops. I have tried following but it seems it doesn't work and many calls will be generated to the same destination. if (!(src_ip==<b2bip> and src_port==5065) and method=="INVITE") { Forward to B2BUA for accounting forward(82.35.57.37,5065); sl_send_reply("181","Forwarding the call to B2BUA"); }; Thanking you in advance Regards Kiarash