Thanks for the reply Philip.
However, before I try STUN and totally abandon nathelper and rtpproxy,I just want to see if anyone know how to solve the below problem. I would suspect since the person who posted the original thread didnt reply after Klaus suggested that he include force_rtp_proxy that he managed to make it work. What I dont understand is where the force_rtp_proxy should be included since it was already in the original config file as shown below.
Any pointers appreciated. (I also tried changing fix_nated_sdp ("1") to ("3") but that didnt work)
Regards, Aisling.
---- Original Message ---- From: lintenhofer@aon.at To: ashling.odriscoll@cit.ie Subject: Re: [Serusers] no audio if clients are behind different nat Date: Mon, 31 Jan 2005 18:22:58 +0100
Ashling O'Driscoll schrieb:
Hi,
I have the exact same problem as described in the below email which
I
found on the serusers mailing archives. That is clients behind the same nat can ring each other and transmit audio but if a client
tries
to ring a client behind another nat no audio is transmitted. According to the below email this is because the sdp is not
rewritten
correctly. The below solution mentions calling force_rtpproxy but that function is called in the original config (see below)...Is
there
a specific plce that it should be invoked?
Thank you, Aisling.
You have to call force_rtpproxy -> this will rewrite the IP address and port with the one of the rtpproxy.
klaus
Sun Yen-Rong (Dan) wrote:
Hi Klaus, Firstly, thanks for your help. I used ethereal to capture the SIP messages, and found out that the SDP in the forwarded INIVITE and
200 OK
message are not rewritten correctly. As a result, the client with a public IP address is sending RTP packets to the private IP address
of
the other client who is behind a NAT. One seruser suggested me to
use
fix_nated_sdp("3") instead of fix_nated_sdp("1"), however, it
didn't
solve my problem. Do I also need to add a parameter to other
nathelper
functions as well?
Regards, Dan.
-----Original Message----- From: Klaus Darilion [mailto:klaus.mailinglists at pernau.at] Sent: Thursday, May 06, 2004 9:45 PM To: Sun Yen-Rong (Dan) Cc: serusers at iptel.org Subject: Re: [Serusers] no audio problem if clients behind NATs
use a packet sniffer (ethereal or ngrep) and watch the SIP messages
at
the SIP proxy. Take a look at the sdp in the forwarded INVITE and
200 OK
message and verify that the IP address and port in the SDP are
rewritten
correctly and points to the rtpproxy.
regards, klaus
Sun Yen-Rong (Dan) wrote:
Hi all,
I am using ser 0.8.12 with nathelper and rtpproxy. When I tried to
make
a call between two clients which are behind the same NAT,
everything
work fine. However, when I try to make a call between clients
which
are
behind different NATs, niether client can hear each other's audio.
my
configuration file is shown in the end of this message. Can
someone
help
me, please?
Thanks,
Dan.
# # $Id: nathelper.cfg,v 1.1.2.1 2003/11/24 14:47:18 janakj Exp $ # # simple quick-start config script including nathelper support
# This default script includes nathelper support. To make it work # you will also have to install Maxim's RTP proxy. The proxy is
enforced
# if one of the parties is behind a NAT. # # If you have an endpoing in the public internet which is known to # support symmetric RTP (Cisco PSTN gateway or voicemail, for
example),
# then you don't have to force RTP proxy. If you don't want to
enforce
# RTP proxy for some destinations than simply use t_relay()
instead
of
# route(1) # # Sections marked with !! Nathelper contain modifications for
nathelper
# # NOTE !! This config is EXPERIMENTAL ! # # ----------- global configuration parameters
debug=3 # debug level (cmd line: -dddddddddd) fork=yes log_stderror=no # (cmd line: -E)
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"
# ------------------ module loading
",# # $Id: nathelper.cfg,v 1.2 2003/04/15 20:35:29 jiri Exp $ # # example script showing use of nathelper module # (incomplete for sake of brevity) #
# ----------- global configuration parameters
# ------------------ 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/textops.so"
# !! Nathelper loadmodule "/usr/local/lib/ser/modules/nathelper.so"
# ----------------- setting module-specific parameters
# -- usrloc params --
modparam("usrloc", "db_mode", 0)
# -- rr params -- # add value to ;lr param to make some broken UAs happy 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
# main 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; };
# !! Nathelper# 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 if (nat_uac_test("3")) { # 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:")){
log("LOG: Someone trying to register from privateIP,
rewriting\n");
# This will work only for user agents that supportsymmetric
# communication. We tested quite many of them andmajority is
# smart enough to be symmetric. In some phones ittakes 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 sourceIP of
signalling if (method == "INVITE") { 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 if (!method=="REGISTER") record_route();
# subsequent messages withing a dialog should take the # path determined by record-routing if (loose_route()) { # mark routing logic in request append_hf("P-hint: rr-enforced\r\n"); route(1); break; };
if (!uri==myself) { # mark routing logic in request append_hf("P-hint: outbound\r\n"); route(1); 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) if (uri==myself) {
if (method=="REGISTER") {# Uncomment this if you want to use digest authentication # if (!www_authorize("iptel.org", "subscriber")) { # www_challenge("iptel.org", "0"); # break; # };
save("location"); break; }; lookup("aliases"); if (!uri==myself) { append_hf("P-hint: outbound alias\r\n"); route(1); break; }; # native SIP destinations are handled using our USRLOCDB
if (!lookup("location")) { sl_send_reply("404", "Not Found"); break; };}; append_hf("P-hint: usrloc applied\r\n"); route(1); }
route[1] { # !! Nathelper if (uri=~"[@:](192.168.|10.|172.(1[6-9]|2[0-9]|3[0-1]).)"
&&
!search("^Route:")){ sl_send_reply("479", "We don't forward to private IP
addresses");
break; };# if client or server know to be behind a NAT, enable relay if (isflagset(6)) { force_rtp_proxy(); };
# NAT processing of replies; apply to all transactions (for
example,
# re-INVITEs from public to private UA are hard to identify as # NATed at the moment of request processing); look at replies t_on_reply("1");
# send it out now; use stateful forwarding as it works reliably # even for UDP2TCP if (!t_relay()) { sl_reply_error(); }; }
# !! Nathelper onreply_route[1] { # NATed transaction ? if (isflagset(6) && status =~ "(183)|2[0-9][0-9]") { fix_nated_contact(); force_rtp_proxy(); # otherwise, is it a transaction behind a NAT and we did not # know at time of request processing ? (RFC1918 contacts) } else if (nat_uac_test("1")) { fix_nated_contact(); }; }
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Serusers mailing list Serusers@iptel.org http://mail.iptel.org/mailman/listinfo/serusers
If it is not symmetric NAT, try to ask a STUN Server outside in the internet. You just need a client which supports STUN (and it works)! The clients learn about the NAT (kind of NAT and outbound address) and change their SDP therefore. A good software choice is XTen lite. A STUN Server is at sip.technikum-wien.at (Ports 3478, 3479)
regards, Philipp
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The above electronic mail transmission is confidential and intended only for the person to whom it is addressed. Its contents may be protected by legal and/or professional privilege. Should it be received by you in error please contact the sender at the above quoted email address. Any unauthorised form of reproduction of this message is strictly prohibited. The Institute does not guarantee the security of any information electronically transmitted and is not liable if the information contained in this communication is not a proper and complete record of the message as transmitted by the sender nor for any delay in its receipt.
-------------------Legal Disclaimer---------------------------------------
The above electronic mail transmission is confidential and intended only for the person to whom it is addressed. Its contents may be protected by legal and/or professional privilege. Should it be received by you in error please contact the sender at the above quoted email address. Any unauthorised form of reproduction of this message is strictly prohibited. The Institute does not guarantee the security of any information electronically transmitted and is not liable if the information contained in this communication is not a proper and complete record of the message as transmitted by the sender nor for any delay in its receipt.
-
Ashling O'Driscoll