[Serusers] Calls between UA´s behind same NAT using nathelper/rtpproxy

Hello I am using avpops module to detect if source IP is the same as destination IP and then comunicate both UAS directly but it doesn't work, please see my configs: ----. if (!lookup("location")) { log(1,"unable to locate user \n"); # handle user which was not found route(4); break; }; ### Test if UAS are in the same NAT: # get the host part of the final uri (IP part) and store it in AVP ID 13 avp_write("$ruri/domain", "i:13"); if (avp_check("i:13","eq/$src_ip/i")) { log(1, "source IP is the same as destination IP\n"); route(3); break; }; avp_delete("i:13/g"); . . # -------------- Same NAT Call Routing (no force rtpproxy) ---- route[3]{ log(1," route[3]: UAs are in the same nat, NO force_rtp_proxy "); if(!t_relay()){ sl_reply_error(); }; } . . . any idea? thanks Rafael Risco