Table of Contents
List of Examples
Table of Contents
This module provides C-API functions to enable Kamailio to be used as an outbound Edge Proxy (see RFC5626 section 5).
The path and rr modules will bind to this module if it is loaded before they are.
Outbound Edge Proxies MUST support STUN NAT keep-alives on their SIP UDP ports. Kamailio supports this though the “stun” module.
The maximum interval at which a User Agent must send a keep-alive may be specified by the Registrar using the Flow-Timer: header in 2xx responses to REGISTERs.
When using TCP or TLS as the SIP transport care should be taken to set the “tcp_connection_lifetime” on the Edge Proxy to a value slightly larger than the interval the Registrar is using for flow timer. Setting “tcp_connection_lifetime” to less than the interval could cause connections to be lost, and setting it to a value much larger than the interval will keep connections open far longer than is required (which is wasteful).
Application-layer keep-alives are optional when the underlying transport already has a keep-alive mechanism. The WebSocket transport has a transport-layer keep-alive. When using the WebSocket transport the “keepalive_timeout” should be set to a value a little greater than the Registrar flow timer interval and a little less than the “tcp_connection_lifetime”.
Example 1.1. Edge Proxy Configuration
#!KAMAILIO
#
# Edge proxy configuration
#
#!subst "/REGISTRAR_IP/192.168.122.3/"
#!subst "/REGISTRAR_PORT/5060/"
#!substdef "/FLOW_TIMER/20/"
####### Global Parameters #########
debug=2
log_stderror=no
log_facility=LOG_LOCAL0
fork=yes
children=4
alias="example.com"
mpath="/usr/lib64/kamailio/modules"
tcp_connection_lifetime=30 # FLOW_TIMER + 10
force_rport=yes
####### Modules Section ########
loadmodule "tm.so"
loadmodule "sl.so"
loadmodule "outbound.so"
loadmodule "rr.so"
loadmodule "path.so"
loadmodule "pv.so"
loadmodule "maxfwd.so"
loadmodule "xlog.so"
loadmodule "sanity.so"
loadmodule "ctl.so"
loadmodule "textops.so"
loadmodule "siputils.so"
loadmodule "stun.so"
# ----------------- setting module-specific parameters ---------------
# ----- tm params -----
modparam("tm", "failure_reply_mode", 3)
# ----- rr params -----
modparam("rr", "append_fromtag", 0)
####### Routing Logic ########
request_route {
route(REQINIT);
if (is_method("CANCEL")) {
if (t_check_trans()) {
route(RELAY);
}
exit;
}
route(WITHINDLG);
t_check_trans();
if (is_method("REGISTER")) {
remove_hf("Route");
add_path();
$du = "sip:REGISTRAR_IP:REGISTRAR_PORT";
} else {
if (is_method("INVITE|SUBSCRIBE"))
record_route();
if (@via[2] == "") {
# From client so route to registrar...
if ($rU == $null) {
sl_send_reply("484", "Address Incomplete");
exit;
}
remove_hf("Route");
$du = "sip:REGISTRAR_IP:REGISTRAR_PORT";
} else {
# From registrar so route using "Route:" headers...
if (!loose_route()) {
switch($rc) {
case -2:
sl_send_reply("403", "Forbidden");
exit;
default:
xlog("L_ERR", "in request_route\n");
sl_reply_error();
exit;
}
}
t_on_failure("FAIL_OUTBOUND");
}
}
route(RELAY);
}
route[RELAY] {
if (!t_relay()) {
sl_reply_error();
}
exit;
}
route[REQINIT] {
if (!mf_process_maxfwd_header("10")) {
sl_send_reply("483","Too Many Hops");
exit;
}
if(!sanity_check("1511", "7"))
{
xlog("Malformed SIP message from $si:$sp\n");
exit;
}
}
route[WITHINDLG] {
if (has_totag()) {
if (!loose_route()) {
switch($rc) {
case -2:
sl_send_reply("403", "Forbidden");
exit;
default:
if (is_method("ACK")) {
if ( t_check_trans() ) {
route(RELAY);
exit;
} else {
exit;
}
}
sl_send_reply("404","Not Found");
}
} else {
if (is_method("NOTIFY")) {
record_route();
}
route(RELAY);
}
exit;
}
}
onreply_route {
if (!t_check_trans()) {
drop;
}
if ($rm == "REGISTER" && $rs >= 200 && $rs <= 299) {
remove_hf("Flow-Timer");
if ($(hdr(Require)[*])=~"outbound")
insert_hf("Flow-Timer: FLOW_TIMER\r\n", "Call-ID");
}
}
failure_route[FAIL_OUTBOUND] {
if (t_branch_timeout() || !t_branch_replied()) {
send_reply("430", "Flow Failed");
}
}
Example 1.2. Registrar Configuration
MAILIO
#
# Registrar configuration
#
####### Global Parameters #########
debug=2
log_stderror=no
log_facility=LOG_LOCAL0
fork=yes
children=4
alias="example.com"
mpath="/usr/lib64/kamailio/modules"
####### Modules Section ########
loadmodule "tm.so"
loadmodule "tmx.so"
loadmodule "sl.so"
loadmodule "rr.so"
loadmodule "pv.so"
loadmodule "maxfwd.so"
loadmodule "xlog.so"
loadmodule "sanity.so"
loadmodule "ctl.so"
loadmodule "textops.so"
loadmodule "siputils.so"
loadmodule "usrloc.so"
loadmodule "registrar.so"
# ----------------- setting module-specific parameters ---------------
# ----- tm params -----
modparam("tm", "failure_reply_mode", 3)
modparam("tm", "restart_fr_on_each_reply", 0)
modparam("tm", "contact_flows_avp", "tm_contact_flows")
modparam("tm", "contacts_avp", "tm_contacts")
# ----- rr params -----
modparam("rr", "append_fromtag", 0)
# ----- registrar params -----
modparam("registrar", "use_path", 1)
modparam("registrar", "gruu_enabled", 1)
modparam("registrar", "outbound_mode", 1)
####### Routing Logic ########
request_route {
route(REQINIT);
if (is_method("CANCEL")) {
if (t_check_trans()) {
route(RELAY);
}
exit;
}
route(WITHINDLG);
t_check_trans();
remove_hf("Route");
if (is_method("INVITE|SUBSCRIBE"))
record_route();
route(REGISTRAR);
if ($rU==$null) {
xlog("L_INFO", "Address Incomplete\n");
send_reply("484","Address Incomplete");
exit;
}
route(LOCATION);
}
route[RELAY] {
if (!t_relay()) {
xlog("L_ERR", "t_relay() failed\n");
sl_reply_error();
}
exit;
}
route[REQINIT] {
if (!mf_process_maxfwd_header("10")) {
xlog("L_INFO", "Too Many Hops\n");
send_reply("483","Too Many Hops");
exit;
}
if(!sanity_check("1511", "7"))
{
xlog("Malformed SIP message from $si:$sp\n");
exit;
}
}
route[WITHINDLG] {
if (has_totag()) {
if (loose_route()) {
if (is_method("NOTIFY")) {
record_route();
}
route(RELAY);
} else {
if (is_method("ACK")) {
if (t_check_trans()) {
route(RELAY);
exit;
} else {
exit;
}
}
xlog("L_INFO", "Not Found");
send_reply("404","Not Found");
}
exit;
}
}
route[REGISTRAR] {
if (is_method("REGISTER"))
{
if (!save("location")) {
xlog("L_ERR", "Unable to save location\n");
sl_reply_error();
}
exit;
}
}
route[LOCATION] {
if (!lookup("location")) {
$var(rc) = $rc;
t_newtran();
switch ($var(rc)) {
case -1:
case -3:
send_reply("404", "Not Found");
exit;
case -2:
send_reply("405", "Method Not Allowed");
exit;
}
}
if (!t_load_contacts() || !t_next_contacts()) {
xlog("L_ERR", "t_(load|next)_contacts() failed\n");
sl_reply_error();
exit;
}
t_on_failure("FAIL_TRANSACTION");
t_on_branch_failure("FAIL-BRANCH");
route(RELAY);
exit;
}
onreply_route {
if (!t_check_trans()) {
drop;
}
}
failure_route[FAIL_TRANSACTION] {
if (!t_check_status("6[0-9][0-9]")) {
if (t_next_contacts()) {
t_relay();
exit;
}
}
if (t_check_status("430")) {
t_reply("480", "Temporarily Unavailable");
exit;
}
}
event_route[tm:branch-failure:FAIL-BRANCH] {
if (t_check_status("403|430")
|| (t_branch_timeout() && !t_branch_replied())) {
unregister("location", "$tu", "$T_reply_ruid");
if (t_next_contact_flow()) {
t_on_branch_failure("FAIL-BRANCH");
t_relay();
}
}
}
The following modules must be loaded before this module:
None
The following modules are required to make proper use of this module:
stun.
The following libraries must be installed before running Kamailio with this module loaded:
A flag which, if set for a request, will force path and rr to add flow tokens to Path: and Record-Route: headers regardless of the request contents.
Default value is -1.
Example 1.3. Set force_outbound_flag parameter
...
modparam("outbound", "force_outbound_flag", 1)
...