check ice in sdp

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

kamailio/nat-traversal-role.cfg

@@ -14,12 +14,14 @@ 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_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"
 
 ####### NAT Traversal Logic ########
 route[NAT_SDP]
@@ -39,7 +41,6 @@ route[NAT_SDP]
 
 route[NAT_DETECT]
 {
-
    if($sel(cfg_get.kazoo.nat_fix_sdp_request) == 1) {
        route(NAT_SDP);
    }
@@ -78,17 +79,28 @@ route[NAT_DETECT]
    if(nat_uac_test(KZ_NAT_DETECT)) {
       xlog("L_DEBUG", "$ci|log|detected nat request\n");
       setflag(FLT_NATS);
-      if (!is_method("REGISTER")) {
-          if(is_first_hop()) set_contact_alias();
-      }
+   }
+
+   if (!is_method("REGISTER")) {
+      if(is_first_hop()) set_contact_alias();
    }
 
 }
 
 route[NAT_MANAGE]
 {
-   if( is_reply() && $sel(cfg_get.kazoo.nat_fix_sdp_reply) == 1) {
-       route(NAT_SDP);
+   if(!isflagset(FLAG_INTERNALLY_SOURCED)) {
+	   if(is_reply() && $sel(cfg_get.kazoo.nat_fix_internal_sdp_reply) == 1) {
+	       if(!sdp_with_ice()) {
+	          route(NAT_SDP);
+	       }
+	   }
+   } else {
+	   if( is_reply() && $sel(cfg_get.kazoo.nat_fix_sdp_reply) == 1) {
+	       if(!sdp_with_ice()) {
+	          route(NAT_SDP);
+	       }
+	   }
    }
 
    if ( is_request() && isflagset(FLAG_INTERNALLY_SOURCED)) {