[Serusers] Forwarding to backup gateway - sr-users

1 Dec 2004


      Hi,
At work are planning to use SER to route traffic between a pstn gateway,
Asterisk, and direct lookups.  We would like to set up the routing to try a
second gateway if it cannot contact the primary gateway.  Below is the
config file and attached is the output from a sample session.
Ideally, we would like to see
If( ! forward to GW2)
Forward(GW1);
}
...
From what I've read in the archives, forward() cannot be used (yes, I tried
it anyway:-) ).  The config below does get to the failure_route but at that
point two errors appear:
1(21749) ERROR: t_forward_nonack: no branched for fwding
1(21749) ERROR: failure_route: t_relay_to failed
Any tips/pointers?
David
# ----------- global configuration parameters ------------------------
listen=XXX.XXX.XXX.XXX
alias=XXX.com
alias=XXX.XXX.com
#debug=3         # debug level (cmd line: -dddddddddd)
#fork=yes
#log_stderror=no            # (cmd line: -E)
/* 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)
#port=5060
#children=4
fifo="/tmp/ser_fifo"
# ------------------ 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"
# 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"
# ----------------- 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)
# -- tm params --
#modparam("tm", "fr_timer", 10)
modparam("tm", "fr_inv_timer", 15)
# -------------------------  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;
};
# 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;
};
# 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;
};
if (method=="INVITE") {
# local user ids
if
(uri=~"^sip:1[0-9][0-9][0-9][0-9][0-9][0-9]@") {
forward("sip.dotality.com");
break;
};
# Phone #s
if
(uri=~"^sip:[2-9][0-9][0-9][0-9][0-9][0-9][0-9]@") {
log("---> TRYING GW2
<---\n");
t_on_failure("1");
t_relay_to_udp("gw2","5060");
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();
};
};
};
}
# Fallback route for pstn gateways.
failure_route[1] {
log("---> TRYING GW1 <---\n");
t_relay_to_udp("GW1","5060");
break;
}