[Serusers] nathelper ERROR: extract_mediaip: no `c=' in SDP

Thu Feb 17 18:47:48 CET 2005

Thanks Marian's help and answer. I can make a call from domainA to
domainB via PDT module.

But I got another error message from nathelper or rtpproxy.
It is "ERROR: extract_mediaip: no `c=' in SDP" from /var/log/messages.
I also find this message at source code of nathelper. So I think it
should happen from this module.

It seems voice channel can't pass throught it. 
I make a call from UA_A ( under NAT ) from domainA and using PDT to
redirect to UA_B via domainB. UA_B has ring and it can answer. I can
hear the UA_A's sound from UA_B. The sound of UA_B is failed to UA_A.

UA_A(NAT) ==> domainA(PDT) ==> domainB(nathelper+rptproxy) ==> UA_B(NAT)
SOUND_A ==========================================> UA_B
UA_A       <===== XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX === SOUND_B

Do I put the prefix2domain() in a wrong place?? Or Is it a bug ofi
nathelper & rtpproxy?

And my ser.cfg as below:

#
# $Id: ser.cfg,v 1.25 2004/11/30 16:28:24 andrei Exp $
#
# simple quick-start config script
#

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

debug=8         # debug level (cmd line: -dddddddddd)
fork=yes
log_stderror=no	# (cmd line: -E)

/* Uncomment these lines to enter debugging mode 
fork=no
log_stderror=yes
*/

listen=xxx.xxx.xxx.xxx

alias=ser.xxx.net
alias=ser
alias=xxx.xxx.xxx.xxx

check_via=no	# (cmd. line: -v)
dns=no           # (cmd. line: -r)
rev_dns=no      # (cmd. line: -R)
port=5060
children=4
fifo_mode=0666
fifo="/tmp/ser_fifo"
fifo_db_url="mysql://ser:heslo@localhost/ser"

# ------------------ module loading ----------------------------------

# Uncomment this if you want to use SQL database
loadmodule "/usr/local/lib/ser/modules/mysql.so"

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"

# Uncomment this if you want digest authentication
# mysql.so must be loaded !
loadmodule "/usr/local/lib/ser/modules/auth.so"
loadmodule "/usr/local/lib/ser/modules/auth_db.so"

# !! Nathelper
loadmodule "/usr/local/lib/ser/modules/nathelper.so"

loadmodule "/usr/local/lib/ser/modules/exec.so"
loadmodule "/usr/local/lib/ser/modules/avpops.so"
loadmodule "/usr/local/lib/ser/modules/domain.so"
loadmodule "/usr/local/lib/ser/modules/group.so"
loadmodule "/usr/local/lib/ser/modules/uri.so"
loadmodule "/usr/local/lib/ser/modules/uri_db.so"
loadmodule "/usr/local/lib/ser/modules/permissions.so"
loadmodule "/usr/local/lib/ser/modules/speeddial.so"
loadmodule "/usr/local/lib/ser/modules/acc.so"
loadmodule "/usr/local/lib/ser/modules/pdt.so"

# ----------------- setting module-specific parameters ---------------

# -- usrloc params --

#modparam("usrloc", "db_mode",   0)

# Uncomment this if you want to use SQL database 
# for persistent storage and comment the previous line
#modparam("usrloc", "db_mode", 2)
modparam("usrloc", "db_mode", 1)

# -- auth params --
# Uncomment if you are using auth module
#
modparam("auth_db", "calculate_ha1", yes)
#
# If you set "calculate_ha1" parameter to yes (which true in this config), 
# uncomment also the following parameter)
#
modparam("auth_db", "password_column", "password")

# -- rr params --
# add value to ;lr param to make some broken UAs happy
modparam("rr", "enable_full_lr", 1)

# -- nathelper params --
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

# -- db_url params --
modparam("acc|auth_db|domain|group|permissions|speeddial|uri_db|usrloc|pdt",
"db_url", "mysql://ser:heslo@localhost/ser")

# -- use_domain params --
modparam("auth_db|group|registrar|speeddial|uri_db|usrloc", "use_domain", 0)

# -- permissions params --
modparam("permissions", "db_mode", 1)
modparam("permissions", "trusted_table", "trusted")

# -- accounting params --
modparam("acc", "db_flag", 1)
modparam("acc", "db_missed_flag", 1)
modparam("acc", "log_fmt", "cdfimorstup")
modparam("acc", "log_level", 1)
modparam("acc", "failed_transactions", 1)
modparam("acc", "report_cancels", 1)
modparam("acc", "report_ack", 0)

# -- domain params --
modparam("domain", "db_mode", 1)

# -- avp params --
modparam("avpops", "avp_url", "mysql://ser:heslo@localhost/ser")
modparam("avpops", "avp_table", "usr_preferences")
#modparam("avpops", "use_domain", "1")
modparam("avpops", "uuid_column", "uuid")
modparam("avpops", "username_column", "username")
modparam("avpops", "domain_column", "domain")
modparam("avpops", "attribute_column", "attribute")
modparam("avpops", "value_column", "value")
modparam("avpops", "type_column", "type")
modparam("avpops", "avp_aliases",
"voicemail=i:500;calltype=i:700;fwd_no_answer_type=i:701;fwd_busy_type=i:702")
# To use more than one tables example
#modparam("avpops", "db_scheme",
"scheme1:table=subscriber;uuid_column=uuid;value_column=first_name")

# -- tm params --
modparam("tm", "fr_timer", 15)
modparam("tm", "fr_inv_timer", 22)
modparam("tm", "wt_timer", 5)
modparam("tm", "fr_inv_timer_avp", "inv_timeout")

# -- pft params --
modparam("pdt", "db_table", "prefix_domain")
modparam("pdt", "prefix", "")
#modparam("pdt", "start_range", 2000)
#modparam("pdt", "terminator", 0)
modparam("pdt", "hsize_2pow", 2)
modparam("pdt", "sync_time", 300)
modparam("pdt", "clean_time", 600)

# -------------------------  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;
	};

	if (method=="INVITE" || method=="BYE") {
		setflag(1);
	};

	# !! 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("SER: 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") {
				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;
	};

	prefix2domain();

	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("ser.xxx.net", "subscriber")) {
				www_challenge("ser.xxx.net", "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 USRLOC DB
		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();
	};
}

On Thu, 17 Feb 2005 12:49:10 +0100, Marian Dumitru
<marian.dumitru at voice-sistem.ro> wrote:
> Hi Charles,
> 
> You have to use interdomain prefixes. Set on domainA a prefix for
> recognizing dialed numbers in domainB.
> The logic is like:
>   PrefixToB+numberInB at domainA -> numberinB at domainB
> 
> you can do this directly from script or by using PDT module.
> 
> Best regards,
> Marian