I config a OP with public IP.And I encount a problem.Two UAs can't invite each other from a same OP.
ua1(private ip)--->nat--->OP1---->register1
ua2(public ip)----->OP1-->register1
 
ua1---invite---->OP1
When ua1 invite ua2,OP1 return 483.The same from ua2 to ua1.
What's wrong? Is my configure file something wrong? Can somebody here help me? 
 
#
# $Id: ser.cfg,v 1.24 2003/11/11 15:32:36 andrei Exp $
#
# simple quick-start config script
#
 
# ----------- global configuration parameters ------------------------
 
#debug=3         # debug level (cmd line: -dddddddddd)
#fork=yes
#log_stderror=no # (cmd line: -E)
 
/* Uncomment these lines to enter debugging mode
*/
#log_stderror=yes
#debug=4
debug =3
fork=yes
log_stderror=yes
check_via=no # (cmd. line: -v)
dns=no           # (cmd. line: -r)
rev_dns=no      # (cmd. line: -R)
port=5070
listen="222.44.22.60"
children=4
fifo="/tmp/ser_fifo"
 
# ------------------ module loading ----------------------------------
 

loadmodule "/home/ser-0.9.3/modules/sl/sl.so"
loadmodule "/home/ser-0.9.3/modules/tm/tm.so"
loadmodule "/home/ser-0.9.3/modules/rr/rr.so"
loadmodule "/home/ser-0.9.3/modules/maxfwd/maxfwd.so"
loadmodule "/home/ser-0.9.3/modules/usrloc/usrloc.so"
loadmodule "/home/ser-0.9.3/modules/textops/textops.so"
loadmodule "/home/ser-0.9.3/modules/nathelper/nathelper.so"
loadmodule "/home/ser-0.9.3/modules/uri/uri.so"
 
# ----------------- setting module-specific parameters ---------------
 
# -- usrloc params --
 
modparam("usrloc", "db_mode",   0)
 
modparam("nathelper", "natping_interval", 30) # Ping interval 30 s
modparam("nathelper", "ping_nated_only", 1)   # Ping only clients behind NAT
modparam("nathelper", "rtpproxy_sock", "/var/run/rtpproxy.sock")
 
modparam("rr", "enable_full_lr", 1)
 
# -------------------------  request routing logic -------------------
 
route{
 
        # -----------------------------------------------------------------
        # Sanity Check Section
        # -----------------------------------------------------------------
        if (!mf_process_maxfwd_header("10")) {
                sl_send_reply("483", "Too Many Hops");
                break;
        };
 
        if (msg:len > max_len) {
                sl_send_reply("513", "Message Overflow");
                break;
        };
        #---------------
  if (method == "REGISTER" || ! search("^Record-Route:"))
   {
   append_hf("Alex-hint: NAThelper\r\n");
   fix_nated_register();
   fix_nated_contact();
 
      if (method == "INVITE")
      {
       append_hf("Alex-hint: SDP rewritten\r\n");
       force_rtp_proxy();
         };
   force_rport();   
   setflag(6);
         };
        #---------------
        # -----------------------------------------------------------------
        # Record Route Section
        # -----------------------------------------------------------------
  if(method != "REGISTER")
  {
   record_route();
  };
 
        if (method=="BYE" || method=="CANCEL") {
                unforce_rtp_proxy();
        }
 
        # -----------------------------------------------------------------
        # Loose Route Section
        # -----------------------------------------------------------------
        if (loose_route()) {
 
                if (has_totag() && (method=="INVITE" || method=="ACK")) {
                        if (nat_uac_test("19")) {
                                setflag(6);
                                force_rport();
                        };
                    force_rtp_proxy("l");
                };
    append_hf("Alex-hint: Loose Route\r\n");
 
                route(1);
                break;
        };
 
        # -----------------------------------------------------------------
        # Call Type Processing Section
        # -----------------------------------------------------------------
 
        if (uri!=myself) {
                route(1);
                break;
        };
 
        if (uri==myself) {
 
                if (method=="CANCEL") {
                        route(3);
                        break;
                } else if (method=="INVITE") {
                        route(3);
                        break;
                } else  if (method=="REGISTER") {
                        route(2);
                        break;
                };
 
                if (uri!=myself) {
                        route(1);
                        break;
                };
        };
 
        route(1);
}
 
route[1] {
 
        # -----------------------------------------------------------------
        # Default Message Handler
        # -----------------------------------------------------------------
 
        t_on_reply("1");
 
        if (!t_relay()) {
                if (method=="INVITE" && isflagset(6)) {
                  unforce_rtp_proxy();
                };
                sl_reply_error();
        };
}
 
route[2] {
 
        # -----------------------------------------------------------------
        # REGISTER Message Handler
        # ----------------------------------------------------------------
 
        if (!search("^Contact:\ +\*") && nat_uac_test("19")) {
                setflag(6);
                fix_nated_register();
                force_rport();
        };
 
        sl_send_reply("100", "Trying");
}
 
route[3] {
 
        # -----------------------------------------------------------------
        # CANCEL and INVITE Message Handler
        # -----------------------------------------------------------------
 
        if (nat_uac_test("19")) {
                setflag(6);
        };
 
        if (uri!=myself) {
                route(1);
                break;
        };
 
        if (isflagset(6)) {
                force_rport();
                #fix_nated_contact();
                force_rtp_proxy();
        };
 
        t_on_reply("1");
 
        if (!t_relay()) {
                if(isflagset(6)) {
                        unforce_rtp_proxy();
                }
                sl_reply_error();
        };
}
 
onreply_route[1] {
 
 if (isflagset(6) || status=~"(180)|(183)|2[0-9][0-9]") {
  if (!search("^Content-Length:\ +0")) {
   force_rtp_proxy();
 
   append_hf("NAT: 1\r\n");
  };
 };
}