[Serusers] nat_uac_test

[C.K]

Hello,

The following is my configuration.

UA1 -> NAT1 -> INTERNET -> NAT2 -> asterisk -> NAT2 ->
INTERNET -> NAT1/3 -> UA2. 

When I run it with the following configuration, the
nat_uac_test doesn't detect that I am behind the NAT,
could any help ? 


# ------------------- global configuration parameters
------------------------

debug=3         # debug level (cmd line: -dddddddddd)
fork=yes
log_stderror=no # (cmd line: -E)

#debug=7
#fork=no
#log_stderror=yes

check_via=no    # (cmd. line: -v)
dns=no           # (cmd. line: -r)
rev_dns=no      # (cmd. line: -R)
port=5060
children=4
fifo="/tmp/ser_fifo"

alias=detone
alias=detone.ghl.com
alias=202.129.171.223
# ------------------- module loading
------------------
loadmodule "/usr/local/lib/ser/modules/sl.so"
loadmodule "/usr/local/lib/ser/modules/tm.so"
loadmodule "/usr/local/lib/ser/modules/rr.so"
loadmodule "/usr/local/lib/ser/modules/maxfwd.so"
loadmodule "/usr/local/lib/ser/modules/usrloc.so"
loadmodule "/usr/local/lib/ser/modules/registrar.so"
loadmodule "/usr/local/lib/ser/modules/exec.so"
loadmodule "/usr/local/lib/ser/modules/xlog.so"
loadmodule "/usr/local/lib/ser/modules/mysql.so"
loadmodule "/usr/local/lib/ser/modules/auth.so"
loadmodule "/usr/local/lib/ser/modules/auth_db.so"
loadmodule "/usr/local/lib/ser/modules/nathelper.so"
loadmodule "/usr/local/lib/ser/modules/textops.so"
# ----------------- setting module-specific parameters
---------------
modparam("usrloc", "db_mode", 2)
modparam("auth_db", "calculate_ha1", yes)
modparam("auth_db", "password_column", "password")

modparam("usrloc", "db_mode", 0)
modparam("rr", "enable_full_lr", 1)

# ------------------ NAThelper ----------------
modparam("registrar", "nat_flag", 6)
modparam("nathelper", "natping_interval", 30) # Ping
interval 30 s
modparam("nathelper", "ping_nated_only", 1)   # Ping
only clients behind NAT

# -------------------------  request routing logic
-------------------
route{

        # initial sanity checks -- messages with
        # max_forwards==0, or excessively long
requests

        if (!mf_process_maxfwd_header("10")) {
                sl_send_reply("483","Too Many Hops");
                break;
        };
        if ( msg:len > max_len ) {
                sl_send_reply("513", "Message too
big");
                break;
        };

	# Special handling for NATed clients; first, NAT test
is
        # executed: it looks for via!=received and
RFC1918 addresses
        # in Contact (may fail if line-folding is
used); also, 
        # the received test should, if completed,
should check all
        # vias for rpesence of received
	xlog("L_NOTICE", "Checking...behind the NAT ?\n");
	if (nat_uac_test("1")) {
		xlog("L_NOTICE", "nat_uac_test=1\n");
	}
	if (nat_uac_test("2")) {
		xlog("L_NOTICE", "nat_uac_test=2\n");
	}
        if (nat_uac_test("3")) {
		xlog("L_NOTICE", "nat_uac_test == 3\n");
                # Allow RR-ed requests, as these may
indicate that
                # a NAT-enabled proxy takes care of
it; unless it is
                # a REGISTER
                
                if (method == "REGISTER" || !
search("^Record-Route:")) { 
                    xlog("L_NOTICE", "Someone trying
to register from private IP, rewriting\n");

                    # This will work only for user
agents that support symmetric
                    # communication. We tested quite
many of them and majority is
                    # smart enough to be symmetric. In
some phones it takes a configuration
                    # option. With Cisco 7960, it is
called NAT_Enable=Yes, with kphone it is
                    # called "symmetric media" and
"symmetric signalling".
                    
                    fix_nated_contact(); # Rewrite
contact with source IP of signalling
                    if (method == "INVITE") { 
			xlog("L_NOTICE", "invite behind NAT.\n");
                        fix_nated_sdp("1"); # Add
direction=active to SDP
                    };
                    force_rport(); # Add rport
parameter to topmost Via
                    setflag(6);    # Mark as NATed
                };
        };
 
	# we record-route all messages -- to make sure that
        # subsequent messages will go through our
proxy; that's
        # particularly good if upstream and downstream
entities
        # use different transport protocol
        record_route();
 
        # loose-route processing
        if (loose_route()) {
		xlog("L_NOTICE", "loose route.\n");
	#	append_hf("P-hint: rr-enforced\r\n");
                t_relay();
                break;
        };


        if
(uri=~"^sip:[0-9][0-9][0-9]*@202.129.171.223") {
		xlog("L_NOTICE", "forward to asterisk.\n");
                forward(10.38.38.14, 5070);
                break;
        };

	# if the request is for other domain use UsrLoc
        # (in case, it does not work, use the
following command
        # with proper names and addresses in it)

	xlog("L_NOTICE", "uri==myself?\n");
	if (uri==myself){

           if (method=="REGISTER") {
	      xlog("L_NOTICE", "register but no NAT.\n");
              sl_send_reply("200", "ok");
              save("location");
              break;
            };

            # native SIP destinations are handled
using our USRLOC DB
            xlog("L_NOTICE", "lookup for USRLOC.\n");
            if (!lookup("location")) {
                sl_send_reply("404", "Not Found");
                break;
            };
        };

	xlog("L_NOTICE", "checking....INVITE\n");
        if (method == "INVITE") {
	  xlog("L_NOTICE", "Invite from not NAT.\n");
          record_route();
	  if (isflagset(4) && isflagset(5)) {
             xlog("L_NOTICE", "UA behind different NAT
devices, forcing rtpproxy\n");
             force_rtp_proxy();
             t_on_reply("2");
          } else {
             xlog("L_NOTICE", "UAs behind same NAT
devicea\n");
             t_on_reply("3");
          }
# for other conditions route here...
        }

        # forward to current uri now; use stateful
forwarding; that
        # works reliably even if we forward from TCP
to UDP
        if (!t_relay()) {
           sl_reply_error();
        };

}

onreply_route[1] {
  if (status =~ "[12][0-9][0-9]"){
      fix_nated_contact();
      force_rtp_proxy();
  }
}


onreply_route[2] {
  if (status == "200" || status == "183"){
     if (isflagset(5)) {
         fix_nated_contact();
      };
      force_rtp_proxy();
  }
}

onreply_route[3] {
  if (status == "200" || status == "183"){
     if (isflagset(5)) {
         fix_nated_contact();
      };
      force_rtp_proxy();
  }
}