New subject: [Serusers] Please help in configuring SER tools

9 Nov 2005


      Hi,
 calls from a UA that is on public ip go through the pstn gw and terminate 
ok.
Calls from behind NAT get a 503 error from the GW when the INVITE message is 
sent from SER.
The invite messages for both cases are the same except from the VIA header 
which for the latter one contains the private ip of the UA.
Contact header is ok.
Could that be the reason that im getting calls rejected?
Is there a way to rewrite the VIA header?
Im including the configuration file i have and some packet dumps of the 
calls.Thanks!
debug=3
fork=no
log_stderror=yes
listen=213.207.***.*** # put your server IP address here
port=5060
children=8
dns=no
rev_dns=no
fifo="/tmp/ser_fifo"
fifo_db_url="mysql://ser:********@localhost/ser"
#KM added module
loadmodule "/usr/lib/ser/modules/exec.so"
loadmodule "/usr/lib/ser/modules/mysql.so"
loadmodule "/usr/lib/ser/modules/sl.so"
loadmodule "/usr/lib/ser/modules/tm.so"
loadmodule "/usr/lib/ser/modules/rr.so"
loadmodule "/usr/lib/ser/modules/maxfwd.so"
loadmodule "/usr/lib/ser/modules/usrloc.so"
loadmodule "/usr/lib/ser/modules/registrar.so"
loadmodule "/usr/lib/ser/modules/auth.so"
loadmodule "/usr/lib/ser/modules/auth_db.so"
loadmodule "/usr/lib/ser/modules/uri.so"
loadmodule "/usr/lib/ser/modules/uri_db.so"
loadmodule "/usr/lib/ser/modules/mediaproxy.so"
loadmodule "/usr/lib/ser/modules/nathelper.so"
loadmodule "/usr/lib/ser/modules/textops.so"
loadmodule "/usr/lib/ser/modules/avpops.so"
loadmodule "/usr/lib/ser/modules/domain.so"
loadmodule "/usr/lib/ser/modules/permissions.so"
modparam("auth_db|permissions|uri_db|usrloc",
"db_url", "mysql://ser:heslo@localhost/ser")
modparam("auth_db", "calculate_ha1", 1)
modparam("auth_db", "password_column", "password")
modparam("nathelper", "rtpproxy_disable", 1)
modparam("nathelper", "natping_interval", 0)
modparam("mediaproxy","natping_interval", 30)
modparam("mediaproxy","mediaproxy_socket", "/var/run/mediaproxy.sock")
modparam("mediaproxy","sip_asymmetrics","/usr/etc/ser/sip-clients")
modparam("mediaproxy","rtp_asymmetrics","/usr/etc/ser/rtp-clients")
modparam("usrloc", "db_mode", 2)
modparam("registrar", "nat_flag", 6)
modparam("rr", "enable_full_lr", 1)
#pstn part-----------------------------------------
modparam("tm", "fr_inv_timer", 27)
modparam("tm", "fr_inv_timer_avp", "inv_timeout")
modparam("permissions", "db_mode", 1)
modparam("permissions", "trusted_table", "trusted")
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;
};
# -----------------------------------------------------------------
# Record Route Section
# -----------------------------------------------------------------
if (method=="INVITE" && client_nat_test("3")) {
# INSERT YOUR IP ADDRESS HERE
record_route_preset("213.207.***.***:5060;nat=yes");
} else if (method!="REGISTER") {
record_route();
};
# -----------------------------------------------------------------
# Call Tear Down Section
# -----------------------------------------------------------------
if (method=="BYE" || method=="CANCEL") {
end_media_session();
};
# -----------------------------------------------------------------
# Loose Route Section
# -----------------------------------------------------------------
if (loose_route()) {
if (has_totag() && (method=="INVITE" || method=="ACK")) {
if (client_nat_test("3") || search("^Route:.*;nat=yes")) {
setflag(6);
use_media_proxy();
#log(1,"route:NATED caller in loose route \n");
};
};
route(1);
break;
};
# -----------------------------------------------------------------
# Call Type Processing Section
# -----------------------------------------------------------------
#Check if the target domain is one that the server is responsible for
if (!is_uri_host_local()) {
log(1,"Call type processing: Target domain is not in the domain pool \n");
#Check to see if the sender is in our own domain and allow messages from 
pstn,pgw
if (is_from_local() || allow_trusted()) {
log(1,"Call type processing: Caller is local or trusted \n");
route(4);
route(1);
} else {
log(1,"Call type processing: 403 error \n");
sl_send_reply("403", "Forbidden");
};
break;
};
if (method=="CANCEL") {
route(1);
break;
} else if (method=="INVITE") {
route(3);
break;
} else if (method=="REGISTER") {
route(2);
break;
};
lookup("aliases");
if (uri!=myself) {
route(4);
route(1);
break;
};
if (!lookup("location")) {
sl_send_reply("404", "User Not Found");
break;
};
route(1);
}
route[1] {
# -----------------------------------------------------------------
# Default Message Handler
# -----------------------------------------------------------------
t_on_reply("1");
if (!t_relay()) {
if (method=="INVITE" || method=="ACK") {
end_media_session();
};
sl_reply_error();
};
}
route[2] {
# -----------------------------------------------------------------
# REGISTER Message Handler
# ----------------------------------------------------------------
sl_send_reply("100", "Trying");
if (!search("^Contact:[ ]**") && client_nat_test("7")) {
setflag(6);
fix_nated_register();
force_rport();
};
if (!www_authorize("","subscriber")) {
www_challenge("","0");
break;
};
if (!check_to()) {
sl_send_reply("401", "Unauthorized");
break;
};
consume_credentials();
if (!save("location")) {
sl_reply_error();
};
}
route[3] {
# -----------------------------------------------------------------
# INVITE Message Handler
# -----------------------------------------------------------------
log (1,"------------route[3]:INVITE handler \n");
#if (allow_trusted()) {log(1,"------------route[3]:User is trusted\n");} ;
#check if NATed caller
if (!search("^Contact:[ ]**") && client_nat_test("7")) {
log (1,"------------route[3]:fixing NAT info \n");
setflag(6);
force_rport();
fix_nated_contact();
};
if (!allow_trusted()) {
if (!proxy_authorize("","subscriber")) {
#log (1,"route[3]:User did not authorise! \n");
proxy_challenge("","1");
#log (1,"route[3]:Sent error 401");
break;
} else if (!check_from()) {
log (1,"route[3]: 403 error \n");
sl_send_reply("403", "Use From=ID");
break;
};
log (1,"route[3]:Consuming credentials.....\n");
consume_credentials();
};
if (client_nat_test("3")) {
setflag(7);
force_rport();
};
#Strip prefix 00357 , 357
if (uri=~"^sip:00357[0-9]{8}@") {
strip(5);
}
else if ( uri=~"^sip:357[0-9]{8}@") {
strip(3);
};
lookup("aliases");
if (uri!=myself) {
route(4);
route(1);
break;
};
if (uri=~"^sip:00[1-9]*@") { # International PSTN 00*
route(4);
route(5);
break;
};
if (!lookup("location")) {
if (uri=~"^sip:[0-9]{8}@") { # Domestic PSTN 2???????
route(4);
route(5);
break;
};
sl_send_reply("404", "User Not Found");
break;
};
route(4);
route(1);
}
route[4] {
# -----------------------------------------------------------------
# NAT Traversal Section
# -----------------------------------------------------------------
if (isflagset(6) || isflagset(7)) {
use_media_proxy();
};
}
route[5] {
# -----------------------------------------------------------------
# PSTN Handler
# -----------------------------------------------------------------
#Change the destination so it points to PGW
rewritehost("213.207.***.***"); # INSERT YOUR PSTN GATEWAY IP ADDRESS
avp_write("i:45", "inv_timeout");
route(4);
route(1);
}
onreply_route[1] {
if ((isflagset(6) || isflagset(7)) && (status=~"(180)|(183)|2[0-9][0-9]")) {
if (!search("^Content-Length:[ ]*0")) {
use_media_proxy();
};
};
if (client_nat_test("1")) {
fix_nated_contact();
};
}
====================================================================================================
Packets for failed call behind NAT:
====================================================================================================
ΤΓ²΅&#0;&#0;&#0;&#0;&#0;&#0;&#0;&#0;&#0;&#0;??&#0;&#0;&#0;&#0;&#0;
½qC~ΐ
&#0;ζ&#0;&#0;ζ&#0;&#0;&#0;ώ-Bΰ&#0;LυE&#0;E&#0;Ψ&#0;D&#0;&#0;pΜΥΟ²ΥΟ³ΔΔΔ&INVITE 
sip:99389683@213.207.141.179 SIP/2.0
Via: SIP/2.0/UDP 192.168.1.6:5060;branch=z9hG4bKfmqE9mAxO4AVb1rE
Max-Forwards: 70
User-Agent: PA168S
From: "22000002" sip:22000002@213.207.141.179;tag=vW5KTCrnEpud7yyE
To: "99389683" sip:99389683@213.207.141.179
Call-ID: Ra1xPN5naYXRZN67@192.168.1.6
Contact: sip:22000002@192.168.1.6:5060
Proxy-Authorization: Digest username="22000002", realm="213.207.141.179", 
nonce="4371b5e37010200b061c47bdd2b9e553e3b7128a1", 
uri="sip:99389683@213.207.141.179", qop=auth, nc=00000001, 
cnonce="0a4f113b", response="805a849373492c421c9397d1621239b5"
CSeq: 2 INVITE
Content-Type: application/sdp
Content-Length: 292
v=0
o=22000002 80268421 80523176 IN IP4 192.168.1.6
s=SIP CALL
c=IN IP4 192.168.1.6
t=0 0
m=audio 11722 RTP/AVP 18 4 0 8 3 97
a=rtpmap:18 G729/8000
a=rtpmap:4 G723/8000
a=rtpmap:0 PCMU/8000
a=rtpmap:8 PCMA/8000
a=rtpmap:3 GSM/8000
a=rtpmap:97 telephone-event/8000
a=fmtp:97 0-15
½qCw
zzLυE&#0;ώ-Bΰ&#0;El&#0;?@&#0;@pγΥΟ³ΥΟ²ΔΔXΙnSIP/2.0 100 trying --  
your call is important to us
Via: SIP/2.0/UDP 
192.168.1.6:5060;branch=z9hG4bKfmqE9mAxO4AVb1rE;rport=5060;received=213.207.141.178
From: "22000002" sip:22000002@213.207.141.179;tag=vW5KTCrnEpud7yyE
To: "99389683" sip:99389683@213.207.141.179
Call-ID: Ra1xPN5naYXRZN67@192.168.1.6
CSeq: 2 INVITE
Server: Sip EXpress router (0.9.3 (i386/linux))
Content-Length: 0
Warning: 392 213.207.141.179:5060 "Noisy feedback tells: pid=8885 
req_src_ip=213.207.141.178 req_src_port=5060 
in_uri=sip:99389683@213.207.141.179 out_uri=sip:99389683@213.207.144.6 
via_cnt==1"
½qCρ
&#0;Δ&#0;&#0;Δ&#0;&#0;&#0;ΉR.&#0;ώ-Bΰ&#0;E?&#0;@&#0;@mDΥΟ³ΥΟΔΔΆΝ
INVITE sip:99389683@213.207.144.6 SIP/2.0
Record-Route: 
sip:99389683@213.207.141.179:5060;nat=yes;ftag=vW5KTCrnEpud7yyE;lr=on
Via: SIP/2.0/UDP 213.207.141.179;branch=z9hG4bK6f55.cba0c054.0
Via: SIP/2.0/UDP 
192.168.1.6:5060;rport=5060;received=213.207.141.178;branch=z9hG4bKfmqE9mAxO4AVb1rE
Max-Forwards: 16
User-Agent: PA168S
From: "22000002" sip:22000002@213.207.141.179;tag=vW5KTCrnEpud7yyE
To: "99389683" sip:99389683@213.207.141.179
Call-ID: Ra1xPN5naYXRZN67@192.168.1.6
Contact: sip:22000002@213.207.141.178:5060
CSeq: 2 INVITE
Content-Type: application/sdp
Content-Length: 316
v=0
o=22000002 80268421 80523176 IN IP4 192.168.1.6
s=SIP CALL
c=IN IP4 213.207.141.179213.207.141.179
t=0 0
m=audio 3506435064 RTP/AVP 18 4 0 8 3 97
a=rtpmap:18 G729/8000
a=rtpmap:4 G723/8000
a=rtpmap:0 PCMU/8000
a=rtpmap:8 PCMA/8000
a=rtpmap:3 GSM/8000
a=rtpmap:97 telephone-event/8000
a=fmtp:97 0-15
½qCy1
Δ&#0;&#0;Δ&#0;&#0;&#0;ΉR.&#0;ώ-Bΰ&#0;E?<@@mCΥΟ³ΥΟΔΔΆΝ
INVITE sip:99389683@213.207.144.6 SIP/2.0
Record-Route: 
sip:99389683@213.207.141.179:5060;nat=yes;ftag=vW5KTCrnEpud7yyE;lr=on
Via: SIP/2.0/UDP 213.207.141.179;branch=z9hG4bK6f55.cba0c054.0
Via: SIP/2.0/UDP 
192.168.1.6:5060;rport=5060;received=213.207.141.178;branch=z9hG4bKfmqE9mAxO4AVb1rE
Max-Forwards: 16
User-Agent: PA168S
From: "22000002" sip:22000002@213.207.141.179;tag=vW5KTCrnEpud7yyE
To: "99389683" sip:99389683@213.207.141.179
Call-ID: Ra1xPN5naYXRZN67@192.168.1.6
Contact: sip:22000002@213.207.141.178:5060
CSeq: 2 INVITE
Content-Type: application/sdp
Content-Length: 316
v=0
o=22000002 80268421 80523176 IN IP4 192.168.1.6
s=SIP CALL
c=IN IP4 213.207.141.179213.207.141.179
t=0 0
m=audio 3506435064 RTP/AVP 18 4 0 8 3 97
a=rtpmap:18 G729/8000
a=rtpmap:4 G723/8000
a=rtpmap:0 PCMU/8000
a=rtpmap:8 PCMA/8000
a=rtpmap:3 GSM/8000
a=rtpmap:97 telephone-event/8000
a=fmtp:97 0-15
½qCh 
΄&#0;&#0;΄&#0;&#0;&#0;ώ-Bΰ&#0;ΉR.&#0;E&#0;¦f~@&#0;ϋNoΥΟΥΟ³ΔΔ'^ 
SIP/2.0 100 Trying
Via: SIP/2.0/UDP 213.207.141.179;branch=z9hG4bK6f55.cba0c054.0
Via: SIP/2.0/UDP 
192.168.1.6:5060;rport=5060;received=213.207.141.178;branch=z9hG4bKfmqE9mAxO4AVb1rE
From: "22000002" sip:22000002@213.207.141.179;tag=vW5KTCrnEpud7yyE
To: "99389683" sip:99389683@213.207.141.179;tag=1367353431
Call-ID: Ra1xPN5naYXRZN67@192.168.1.6
CSeq: 2 INVITE
Content-Length: 0
½qCο&#0;&#0;΄&#0;&#0;΄&#0;&#0;&#0;ώ-Bΰ&#0;ΉR.&#0;E&#0;¦f@&#0;ϋNnΥΟΥΟ³ΔΔ'^ 
SIP/2.0 100 Trying
Via: SIP/2.0/UDP 213.207.141.179;branch=z9hG4bK6f55.cba0c054.0
Via: SIP/2.0/UDP 
192.168.1.6:5060;rport=5060;received=213.207.141.178;branch=z9hG4bKfmqE9mAxO4AVb1rE
From: "22000002" sip:22000002@213.207.141.179;tag=vW5KTCrnEpud7yyE
To: "99389683" sip:99389683@213.207.141.179;tag=1367353431
Call-ID: Ra1xPN5naYXRZN67@192.168.1.6
CSeq: 2 INVITE
Content-Length: 0
½qCΎΊ&#0;ξ&#0;&#0;ξ&#0;&#0;&#0;ώ-Bΰ&#0;ΉR.&#0;E&#0;ΰf?@ϋN3ΥΟΥΟ³ΔΔΜ"SIP/2.0 
503 Service Unavailable
Via: SIP/2.0/UDP 213.207.141.179;branch=z9hG4bK6f55.cba0c054.0
Via: SIP/2.0/UDP 
192.168.1.6:5060;rport=5060;received=213.207.141.178;branch=z9hG4bKfmqE9mAxO4AVb1rE
From: "22000002" sip:22000002@213.207.141.179;tag=vW5KTCrnEpud7yyE
To: "99389683" sip:99389683@213.207.141.179;tag=1367353431
Call-ID: Ra1xPN5naYXRZN67@192.168.1.6
CSeq: 2 INVITE
Contact: sip:99389683@213.207.144.6:5060
Content-Length: 0
½qCe»""ΉR.&#0;ώ-Bΰ&#0;E.&#0;@&#0;@osΥΟ³ΥΟΔΔqΚΫACK 
sip:99389683@213.207.144.6 SIP/2.0
Via: SIP/2.0/UDP 213.207.141.179;branch=z9hG4bK6f55.cba0c054.0
From: "22000002" sip:22000002@213.207.141.179;tag=vW5KTCrnEpud7yyE
Call-ID: Ra1xPN5naYXRZN67@192.168.1.6
To: "99389683" sip:99389683@213.207.141.179;tag=1367353431
CSeq: 2 ACK
User-Agent: Sip EXpress router(0.9.3 (i386/linux))
Content-Length: 0
½qC>»RRLυE&#0;ώ-Bΰ&#0;E @@q«ΥΟ³ΥΟ²ΔΔΘΆSIP/2.0 503 Service 
Unavailable
Via: SIP/2.0/UDP 
192.168.1.6:5060;rport=5060;received=213.207.141.178;branch=z9hG4bKfmqE9mAxO4AVb1rE
From: "22000002" sip:22000002@213.207.141.179;tag=vW5KTCrnEpud7yyE
To: "99389683" sip:99389683@213.207.141.179;tag=1367353431
Call-ID: Ra1xPN5naYXRZN67@192.168.1.6
CSeq: 2 INVITE
Contact: sip:99389683@213.207.144.6:5060
Content-Length: 0
½qCn&#0;?&#0;&#0;?&#0;&#0;&#0;ώ-Bΰ&#0;LυE&#0;E&#0;&#0;E&#0;&#0;r 
ΥΟ²ΥΟ³ΔΔ"ACK sip:99389683@213.207.141.179 SIP/2.0
Via: SIP/2.0/UDP 192.168.1.6:5060;branch=z9hG4bKfmqE9mAxO4AVb1rE
Max-Forwards: 70
User-Agent: PA168S
From: "22000002" sip:22000002@213.207.141.179;tag=vW5KTCrnEpud7yyE
To: "99389683" sip:99389683@213.207.141.179;tag=1367353431
Call-ID: Ra1xPN5naYXRZN67@192.168.1.6
Contact: sip:22000002@192.168.1.6:5060
Proxy-Authorization: Digest username="22000002", realm="213.207.141.179", 
nonce="4371be370510200b061c47bdd2b9e553e3b7128a1", 
uri="sip:99389683@213.207.141.179", qop=auth, nc=00000001, 
cnonce="0a4f113b", response="805a849373492c421c9397d1621239b5"
CSeq: 2 ACK
Content-Length: 0
½qCΕ8
&#0;RRLυE&#0;ώ-Bΰ&#0;E &#0;@&#0;@q?ΥΟ³ΥΟ²ΔΔΘΆSIP/2.0 503 
Service Unavailable
Via: SIP/2.0/UDP 
192.168.1.6:5060;rport=5060;received=213.207.141.178;branch=z9hG4bKfmqE9mAxO4AVb1rE
From: "22000002" sip:22000002@213.207.141.179;tag=vW5KTCrnEpud7yyE
To: "99389683" sip:99389683@213.207.141.179;tag=1367353431
Call-ID: Ra1xPN5naYXRZN67@192.168.1.6
CSeq: 2 INVITE
Contact: sip:99389683@213.207.144.6:5060
Content-Length: 0
½qCγέ
&#0;?&#0;&#0;?&#0;&#0;&#0;ώ-Bΰ&#0;LυE&#0;E&#0;&#0;F&#0;&#0;rΥΟ²ΥΟ³ΔΔ"ACK 
sip:99389683@213.207.141.179 SIP/2.0
Via: SIP/2.0/UDP 192.168.1.6:5060;branch=z9hG4bKfmqE9mAxO4AVb1rE
Max-Forwards: 70
User-Agent: PA168S
From: "22000002" sip:22000002@213.207.141.179;tag=vW5KTCrnEpud7yyE
To: "99389683" sip:99389683@213.207.141.179;tag=1367353431
Call-ID: Ra1xPN5naYXRZN67@192.168.1.6
Contact: sip:22000002@192.168.1.6:5060
Proxy-Authorization: Digest username="22000002", realm="213.207.141.179", 
nonce="4371be370105200b061c47bdd2b9e553e3b7128a1", 
uri="sip:99389683@213.207.141.179", qop=auth, nc=00000001, 
cnonce="0a4f113b", response="805a849373492c421c9397d1621239b5"
CSeq: 2 ACK
Content-Length: 0
½qC3G
RRLυE&#0;ώ-Bΰ&#0;E @@q©ΥΟ³ΥΟ²ΔΔΘΆSIP/2.0 503 Service 
Unavailable
Via: SIP/2.0/UDP 
192.168.1.6:5060;rport=5060;received=213.207.141.178;branch=z9hG4bKfmqE9mAxO4AVb1rE
From: "22000002" sip:22000002@213.207.141.179;tag=vW5KTCrnEpud7yyE
To: "99389683" sip:99389683@213.207.141.179;tag=1367353431
Call-ID: Ra1xPN5naYXRZN67@192.168.1.6
CSeq: 2 INVITE
Contact: sip:99389683@213.207.144.6:5060
Content-Length: 0
½qC.κ
&#0;?&#0;&#0;?&#0;&#0;&#0;ώ-Bΰ&#0;LυE&#0;E&#0;&#0;G&#0;&#0;rΥΟ²ΥΟ³ΔΔ"ACK 
sip:99389683@213.207.141.179 SIP/2.0
Via: SIP/2.0/UDP 192.168.1.6:5060;branch=z9hG4bKfmqE9mAxO4AVb1rE
Max-Forwards: 70
User-Agent: PA168S
From: "22000002" sip:22000002@213.207.141.179;tag=vW5KTCrnEpud7yyE
To: "99389683" sip:99389683@213.207.141.179;tag=1367353431
Call-ID: Ra1xPN5naYXRZN67@192.168.1.6
Contact: sip:22000002@192.168.1.6:5060
Proxy-Authorization: Digest username="22000002", realm="213.207.141.179", 
nonce="4371be370102005b061c47bdd2b9e553e3b7128a1", 
uri="sip:99389683@213.207.141.179", qop=auth, nc=00000001, 
cnonce="0a4f113b", response="805a849373492c421c9397d1621239b5"
CSeq: 2 ACK
Content-Length: 0
½qCd
RRLυE&#0;ώ-Bΰ&#0;E @@q¨ΥΟ³ΥΟ²ΔΔΘΆSIP/2.0 503 Service 
Unavailable
Via: SIP/2.0/UDP 
192.168.1.6:5060;rport=5060;received=213.207.141.178;branch=z9hG4bKfmqE9mAxO4AVb1rE
From: "22000002" sip:22000002@213.207.141.179;tag=vW5KTCrnEpud7yyE
To: "99389683" sip:99389683@213.207.141.179;tag=1367353431
Call-ID: Ra1xPN5naYXRZN67@192.168.1.6
CSeq: 2 INVITE
Contact: sip:99389683@213.207.144.6:5060
Content-Length: 0
½qCA&#0;?&#0;&#0;?&#0;&#0;&#0;ώ-Bΰ&#0;LυE&#0;E&#0;&#0;H&#0;&#0;rΥΟ²ΥΟ³ΔΔ"ACK 
sip:99389683@213.207.141.179 SIP/2.0
Via: SIP/2.0/UDP 192.168.1.6:5060;branch=z9hG4bKfmqE9mAxO4AVb1rE
Max-Forwards: 70
User-Agent: PA168S
From: "22000002" sip:22000002@213.207.141.179;tag=vW5KTCrnEpud7yyE
To: "99389683" sip:99389683@213.207.141.179;tag=1367353431
Call-ID: Ra1xPN5naYXRZN67@192.168.1.6
Contact: sip:22000002@192.168.1.6:5060
Proxy-Authorization: Digest username="22000002", realm="213.207.141.179", 
nonce="4371be370102005b061c47bdd2b9e553e3b7128a1", 
uri="sip:99389683@213.207.141.179", qop=auth, nc=00000001, 
cnonce="0a4f113b", response="805a849373492c421c9397d1621239b5"
CSeq: 2 ACK
Content-Length: 0
====================================================================================================
Packets for successful call from public IP:
====================================================================================================
ΤΓ²΅&#0;&#0;&#0;&#0;&#0;&#0;&#0;&#0;&#0;&#0;??&#0;&#0;&#0;&#0;&#0;½qCjlΏ&#0;&#0;Ώ&#0;&#0;&#0;ώ-Bΰ&#0;ΪβΗ&#0;Eh±%*ϊΟ΅ΥΟ?ΥΟ³ΔΔίINVITE 
sip:22372673@213.207.141.179 SIP/2.0
Via: SIP/2.0/UDP 213.207.141.181:5060;branch=z9hG4bK-896914ce
From: Kyriakos sip:22000001@213.207.141.179;tag=2f2e13766c08ee3ao0
To: sip:22372673@213.207.141.179
Call-ID: fa843926-7b99844a@213.207.141.181
CSeq: 102 INVITE
Max-Forwards: 70
Proxy-Authorization: Digest 
username="22000001",realm="213.207.141.179",nonce="4371be42f095d84938c2b65fb9b1d879749453b6e",uri="sip:22372673@213.207.141.179",algorithm=MD5,response="cf863bab65ffbaf6376746eb76cd127c",qop=auth,nc=00000001,cnonce="32d92d6b"
Contact: Kyriakos sip:22000001@213.207.141.181:5060
Expires: 240
User-Agent: Sipura/SPA841-3.1.1(a)
Content-Length: 403
Allow: ACK, BYE, CANCEL, INFO, INVITE, NOTIFY, OPTIONS, REFER
Content-Type: application/sdp
v=0
o=- 8038585 8038585 IN IP4 213.207.141.181
s=-
c=IN IP4 213.207.141.181
t=0 0
m=audio 16460 RTP/AVP 0 2 4 8 18 96 97 98 101
a=rtpmap:0 PCMU/8000
a=rtpmap:2 G726-32/8000
a=rtpmap:4 G723/8000
a=rtpmap:8 PCMA/8000
a=rtpmap:18 G729a/8000
a=rtpmap:96 G726-40/8000
a=rtpmap:97 G726-24/8000
a=rtpmap:98 G726-16/8000
a=rtpmap:101 telephone-event/8000
a=fmtp:101 0-15
a=ptime:30
a=sendrecv
½qCoOOΪβΗ&#0;ώ-Bΰ&#0;EA&#0;'@&#0;@qΥΟ³ΥΟ?ΔΔ-ΙFSIP/2.0 100 
trying -- your call is important to us
Via: SIP/2.0/UDP 213.207.141.181:5060;branch=z9hG4bK-896914ce
From: Kyriakos sip:22000001@213.207.141.179;tag=2f2e13766c08ee3ao0
To: sip:22372673@213.207.141.179
Call-ID: fa843926-7b99844a@213.207.141.181
CSeq: 102 INVITE
Server: Sip EXpress router (0.9.3 (i386/linux))
Content-Length: 0
Warning: 392 213.207.141.179:5060 "Noisy feedback tells: pid=8885 
req_src_ip=213.207.141.181 req_src_port=5060 
in_uri=sip:22372673@213.207.141.179 out_uri=sip:22372673@213.207.144.6 
via_cnt==1"
½qC[oAAΉR.&#0;ώ-Bΰ&#0;E3&#0;"@&#0;@lΎΥΟ³ΥΟΔΔΝ?INVITE 
sip:22372673@213.207.144.6 SIP/2.0
Record-Route: sip:213.207.141.179;ftag=2f2e13766c08ee3ao0;lr=on
Via: SIP/2.0/UDP 213.207.141.179;branch=z9hG4bKc56.673dbf01.0
Via: SIP/2.0/UDP 213.207.141.181:5060;branch=z9hG4bK-896914ce
From: Kyriakos sip:22000001@213.207.141.179;tag=2f2e13766c08ee3ao0
To: sip:22372673@213.207.141.179
Call-ID: fa843926-7b99844a@213.207.141.181
CSeq: 102 INVITE
Max-Forwards: 16
Contact: Kyriakos sip:22000001@213.207.141.181:5060
Expires: 240
User-Agent: Sipura/SPA841-3.1.1(a)
Content-Length: 403
Allow: ACK, BYE, CANCEL, INFO, INVITE, NOTIFY, OPTIONS, REFER
Content-Type: application/sdp
v=0
o=- 8038585 8038585 IN IP4 213.207.141.181
s=-
c=IN IP4 213.207.141.181
t=0 0
m=audio 16460 RTP/AVP 0 2 4 8 18 96 97 98 101
a=rtpmap:0 PCMU/8000
a=rtpmap:2 G726-32/8000
a=rtpmap:4 G723/8000
a=rtpmap:8 PCMA/8000
a=rtpmap:18 G729a/8000
a=rtpmap:96 G726-40/8000
a=rtpmap:97 G726-24/8000
a=rtpmap:98 G726-16/8000
a=rtpmap:101 telephone-event/8000
a=fmtp:101 0-15
a=ptime:30
a=sendrecv
½qCΏα&#0;&#0;&#0;&#0;&#0;&#0;ώ-Bΰ&#0;ΉR.&#0;E&#0;zf@&#0;ϋNΥΟΥΟ³ΔΔf"QSIP/2.0 
100 Trying
Via: SIP/2.0/UDP 213.207.141.179;branch=z9hG4bKc56.673dbf01.0
Via: SIP/2.0/UDP 213.207.141.181:5060;branch=z9hG4bK-896914ce
From: Kyriakos sip:22000001@213.207.141.179;tag=2f2e13766c08ee3ao0
To: sip:22372673@213.207.141.179;tag=1367353431
Call-ID: fa843926-7b99844a@213.207.141.181
CSeq: 102 INVITE
Content-Length: 0

[Serusers] Calls from UAs behind NAT getting a 503 error...

Packets for failed call behind NAT:

Packets for successful call from public IP: