check ice in sdp for requests

* ip replacement only if sdp doesn't have ice candidates
* don't do ip replacement from internal by default

(cherry picked from commit 1ff059c573)

kamailio/nat-traversal-role.cfg

@@ -15,13 +15,15 @@ modparam("nathelper", "sipping_from", "sip:registrar@MY_HOSTNAME")
 #!trydef KZ_NAT_FIX_SDP_REQUEST 1
 #!trydef KZ_NAT_FIX_SDP_REPLY 1
 #!trydef KZ_NAT_FIX_INTERNAL_SDP_REPLY 0
+#!trydef KZ_NAT_FIX_INTERNAL_SDP_REQUEST 0
 #!trydef KZ_NAT_SDP_TEST 8
 #!trydef KZ_NAT_SDP_FIX 10
 
 
 kazoo.nat_fix_sdp_request = KZ_NAT_FIX_SDP_REQUEST descr "performs request sdp replacement of private addresses"
 kazoo.nat_fix_sdp_reply = KZ_NAT_FIX_SDP_REPLY descr "performs reply sdp replacement of private addresses"
-kazoo.nat_fix_internal_sdp_reply = KZ_NAT_FIX_INTERNAL_SDP_REPLY descr "performs reply sdp replacement of private addresses"
+kazoo.nat_fix_internal_sdp_request = KZ_NAT_FIX_INTERNAL_SDP_REQUEST descr "performs internal request sdp replacement of private addresses"
+kazoo.nat_fix_internal_sdp_reply = KZ_NAT_FIX_INTERNAL_SDP_REPLY descr "performs internal reply sdp replacement of private addresses"
 
 ####### NAT Traversal Logic ########
 route[NAT_SDP]
@@ -41,8 +43,19 @@ route[NAT_SDP]
 
 route[NAT_DETECT]
 {
-   if($sel(cfg_get.kazoo.nat_fix_sdp_request) == 1) {
-       route(NAT_SDP);
+
+   if(isflagset(FLAG_INTERNALLY_SOURCED)) {
+	   if(is_request() && $sel(cfg_get.kazoo.nat_fix_internal_sdp_request) == 1) {
+	       if(!sdp_with_ice()) {
+	          route(NAT_SDP);
+	       }
+	   }
+   } else {
+	   if(is_request() && $sel(cfg_get.kazoo.nat_fix_sdp_request) == 1) {
+	       if(!sdp_with_ice()) {
+	          route(NAT_SDP);
+	       }
+	   }
    }
 
    if ($Rp == "5080") {