[Serusers] RTP proxy between two subnetworks with private @s - sr-users

20 Sep 2005


      Hi,
I am trying to figure out how to solve the follwoing problem.
I have two subnetworks, A and B, with different private ip adressing
schemes (IP@A mailto:IP@A ) and (IP@B mailto:IP@B ).
SER is installed in a computer with network interfaces towards both
subnetworks.
SER's SIP signalling proxying operation works properly within the
subnetworks and when trying to set up a communication between users in A
and B. But in that last case, obviously there is no media at all
circulating among the subnetworks.
Portaone's RTP proxy has been installed and configured in the computer
with interfaces towards both subnetworks where SER is installed.
I am trying to configure SER so that, based on the nathelper module,
when communication between both subnetworks occurs, the RTP proxy is
involved and the communication (also media and not only signalling) is
possible. BUT I am making something wrong, becouse it does not work ...
Can anyone give me  a hand /hint?
Thanks a lot in advance / in any case.
My SER config file is the following:
#
# ----------- global configuration parameters ------------------------
/* Uncomment these lines to enter debugging mode
debug=7
fork=no
log_stderror=yes
*/
check_via=no # (cmd. line: -v)
dns=no # (cmd. line: -r)
rev_dns=no # (cmd. line: -R)
fifo="/tmp/ser_fifo"
fifo_mode=0662
alias=wirelessip.x.x.x
alias=sip..x.x.x
alias=x.x.x
log_stderror=no
debug=3
children=3
mhomed=1
# ------------------ module loading ----------------------------------
# Uncomment this if you want to use SQL database
loadmodule "/lib/ser/modules/mysql.so"
loadmodule "/lib/ser/modules/sl.so"
loadmodule "/lib/ser/modules/tm.so"
loadmodule "/lib/ser/modules/rr.so"
loadmodule "/lib/ser/modules/maxfwd.so"
loadmodule "/lib/ser/modules/usrloc.so"
loadmodule "/lib/ser/modules/textops.so"
loadmodule "/lib/ser/modules/registrar.so"
# Uncomment this if you want digest authentication
# mysql.so must be loaded !
loadmodule "/lib/ser/modules/auth.so"
loadmodule "/lib/ser/modules/auth_db.so"
# For NAT support / media proxying
loadmodule "/lib/ser/modules/nathelper.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)
# -- 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)
# For NAT
# We will use flag 6 to mark NATed contacts
modparam("registrar", "nat_flag", 6)
# Enable NAT pinging
modparam("nathelper", "natping_interval", 60)
# Ping only contacts that are known to be
# behind NAT
modparam("nathelper", "ping_nated_only", 1)
# ------------------------- 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;
};
# 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 used); also,
# the received test should, if complete, should check all
# vias for presence 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 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 smart enough to be symmetric. In some phones, like
# it takes a configuration option. With Cisco 7960, it is
# called NAT_Enable=Yes, with kphone it is called
# "symmetric media" and "symmetric signaling". (The latter
# not part of public released yet.)
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
record_route();
# loose-route processing
if (loose_route()) {
t_relay();
break;
};
lookup("aliases");
# 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("com.dtu.dk", "subscriber")) {
www_challenge("com.dtu.dk", "0");
break;
};
save("location");
break;
};
# native SIP destinations are handled using our USRLOC DB
if (!lookup("location")) {
sl_send_reply("404", "Not Found");
break;
};
};
# 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();
};
}
#
# Forcing media relay if necessary
#
route[1] {
#if (uri=~"[@:](192.168.|10.|172.16)" && !search("^Route:")){
# sl_send_reply("479", "We don't forward to private IP addresses");
# break;
#};
#if (isflagset(6)) {
force_rtp_proxy(); # I force everything through the proxy
t_on_reply("1");
append_hf("P-Behind-NAT: Yes\r\n");
#};
if (!t_relay()) {
sl_reply_error();
break;
};
}
onreply_route[1] {
if (status =~ "(183)|2[0-9][0-9]") {
fix_nated_contact();
force_rtp_proxy();
};
}