diff --git a/kamailio/dbtext/address b/kamailio/dbtext/address
new file mode 100644
index 0000000..6d5674f
--- /dev/null
+++ b/kamailio/dbtext/address
@@ -0,0 +1,2 @@
+id(int,auto) grp(int) ip_addr(string) mask(int) port(int) tag(string,null)
+0:1:10.10.10.10:32:0:Known Gateway
diff --git a/kamailio/dbtext/trusted b/kamailio/dbtext/trusted
new file mode 100644
index 0000000..4ff5902
--- /dev/null
+++ b/kamailio/dbtext/trusted
@@ -0,0 +1 @@
+id(int,auto) src_ip(string) proto(string) from_pattern(string,null) tag(string,null) 
diff --git a/kamailio/dbtext/version b/kamailio/dbtext/version
new file mode 100644
index 0000000..4f6be33
--- /dev/null
+++ b/kamailio/dbtext/version
@@ -0,0 +1,3 @@
+table_name(string) table_version(int)
+address:6
+trusted:5
diff --git a/kamailio/default.cfg b/kamailio/default.cfg
index f4f214c..fef2497 100644
--- a/kamailio/default.cfg
+++ b/kamailio/default.cfg
@@ -28,6 +28,8 @@ flags
 #!define FLB_NATSIPPING 2
 #!define FLB_UAC_REDIRECT 3
 
+#!define TRUSTED_ADR_GROUP 1
+
 ####### Global Parameters #########
 fork = yes
 children = 25
@@ -164,6 +166,9 @@ modparam("mi_fifo", "fifo_name", "/tmp/kamailio_fifo")
 ######## UAC Redirection module ########
 loadmodule "uac_redirect.so"
 
+######## DoS prevention mdule ########
+loadmodule "pike.so"
+
 ####### Role Configurations ##########
 #!ifdef DISPATCHER-ROLE
 include_file "dispatcher-role.cfg"
@@ -183,6 +188,13 @@ include_file "nat-traversal-role.cfg"
 loadmodule "db_kazoo.so"
 #!endif
 
+loadmodule "db_text.so"
+loadmodule "permissions.so"
+modparam("db_text", "db_mode", 1)
+modparam("permissions", "db_url", "text:///etc/kamailio/dbtext")
+modparam("permissions", "db_mode", 1)
+
+
 ####### Routing Logic ########
 route
 {
@@ -198,6 +210,8 @@ route
     route(DISPATCHER_CLASSIFY_SOURCE);
     #!endif
 
+    route(DOS_PREVENTION);
+
     route(HANDLE_OPTIONS);
 
     route(HANDLE_MOVE_REQUEST);
@@ -231,7 +245,12 @@ route[SANITY_CHECK]
 {
     if (!mf_process_maxfwd_header("10")) {
         xlog("L_WARN", "$ci|end|Too much hops, not enough barley");
-        sl_send_reply("483", "Too Many Hops");
+        send_reply("483", "Too Many Hops");
+        exit;
+    }
+
+    if ( msg:len > 6144 ) {
+        send_reply("513", "Message too large");
         exit;
     }
 
@@ -246,6 +265,10 @@ route[HANDLE_OPTIONS]
     if (is_method("OPTIONS")) {
         if (isflagset(FLAG_INTERNALLY_SOURCED)) {
             route(INTERNAL_TO_EXTERNAL_RELAY);
+        }
+        else 
+        if ($rd=~ "[0-9]{1,3}\.[0-9]{1,3}.[0-9]{1,3}\.[0-9]{1,3}") {
+            xlog("L_ERR", "Possible attack- Options: to $ru from $fu, UA $ua, IP $si\n");
         } else {
             sl_send_reply("200", "Rawr!!");
         }
@@ -373,6 +396,37 @@ route[EXTERNAL_TO_INTERNAL_RELAY]
     t_relay();
 }
 
+route[DOS_PREVENTION]
+{
+    # allow request from internal network or from whitelist
+    if (isflagset(FLAG_INTERNALLY_SOURCED) || allow_source_address(TRUSTED_ADR_GROUP)) {
+        xlog("L_DBG", "Request from trusted IP $rm $si\n");
+        return;
+    }
+
+    #  drop requests with no To domain or IP To domain (friendly-scanner)
+    if (is_method("REGISTER|SUBSCRIBE|OPTIONS") && 
+        ($td == $null || $td=~ "[0-9]{1,3}\.[0-9]{1,3}.[0-9]{1,3}\.[0-9]{1,3}")) {
+        xlog("L_ERR", "Possible attack- wrong td: $rm to $ru from $fu, UA $ua, IP $si\n");
+        exit;
+    }
+
+    # drop Invite with IP auth realm
+    if (is_method("INVITE") && is_present_hf("Proxy-Authorization") && 
+        $ar =~ "[0-9]{1,3}\.[0-9]{1,3}.[0-9]{1,3}\.[0-9]{1,3}" ) {
+        xlog("L_ERR", "Possible attack- Invite realm $ar: to $ru from $fu, UA $ua, IP $si\n");
+        exit;
+    }
+
+    # use pike check for the others
+    if (!pike_check_req()) {
+        if( $rc == -2) {
+            xlog("L_ERR", "DOS attack: $rm to $ru from $fu, UA $ua, IP $si\n");
+        }
+        exit;
+    }
+}
+
 onreply_route[EXTERNAL_REPLY] 
 {
     xlog("L_INFO", "$ci|log|external reply $T_reply_code");
@@ -467,4 +521,4 @@ onsend_route {
     xlog("L_INFO", "$ci|pass|$sndfrom(ip):$sndfrom(port) -> $sndto(ip):$sndto(port)");
 }
 
-## vim:set tabstop=4 softtabstop=4 shiftwidth=4 expandtab
+# vim: tabstop=4 softtabstop=4 shiftwidth=4 expandtab
diff --git a/kamailio/dispatcher-role.cfg b/kamailio/dispatcher-role.cfg
index 713ac74..b9fd1fd 100644
--- a/kamailio/dispatcher-role.cfg
+++ b/kamailio/dispatcher-role.cfg
@@ -40,12 +40,49 @@ route[DISPATCHER_FIND_ROUTES]
         return;
     }
 
-    if (!ds_select_dst("1", "0")) {
-        xlog("L_ERR", "$ci|end|no servers avaliable");
+    if (is_method("SUBSCRIBE")) {
+        $var(ds_group) = 20;
+    } else
+    if (is_method("REGISTER")) {
+        $var(ds_group) = 30;
+    } else {
+        $var(ds_group) = 1;
+    }
+
+    if (!ds_select_dst("$var(ds_group)", "0")) {
+        xlog("L_ERR", "$ci|end|no servers avaliable in group $var(ds_group)");
+
+        # if we selected from group 1, try again in group 2
+        if ($var(ds_group) == 1 ) {
+
+                if (!ds_select_dst("2", "0")) {
+                    xlog("L_ERR", "$ci|end|no servers avaliable in group 2");
+                    sl_send_reply("480", "All servers busy");
+                    exit;
+                }
+
+        } else {
+
+            sl_send_reply("480", "All servers busy");
+            exit;
 
-        sl_send_reply("480", "All servers busy");
+        }
+    } else {
+
+        # if we selected from group 1 and there are less than 3 available servers, choose from group 2
+        if ($var(ds_group) == 1 && $var(ds_cnt)< 3) {
+
+            # clear $avp(ds_dst) and search in group 2
+            $(avp(ds_dst)[*]) = $null;
+
+            if (!ds_select_dst("2", "0")) {
+                xlog("L_ERR", "$ci|end|no servers avaliable in group 2");
+                sl_send_reply("480", "All servers busy");
+                exit;
+            }
+
+        }
 
-        exit;
     }
 
     $var(contact_uri) = $(ct{tobody.user}) + "@" + $(ct{tobody.host});
diff --git a/kamailio/registrar-role.cfg b/kamailio/registrar-role.cfg
index ef267ba..24d0697 100644
--- a/kamailio/registrar-role.cfg
+++ b/kamailio/registrar-role.cfg
@@ -2,6 +2,7 @@
 
 ######## Generic Hash Table container in shared memory ########
 modparam("htable", "htable", "auth_cache=>size=16;autoexpire=7200")
+modparam("htable", "htable", "failed_auth_hash=>size=14;autoexpire=180;")
 
 ####### Authentication Interface module ##########
 loadmodule "auth.so"
@@ -37,6 +38,9 @@ modparam("registrar", "received_avp", "$avp(AVP_RECV_PARAM)")
 route[HANDLE_REGISTER]
 {
     if (is_method("REGISTER")) {
+
+        route(DOMAIN_FORMAT_CHECK);
+
         #!ifdef NAT-TRAVERSAL-ROLE
         if (nat_uac_test("3")) {
             xlog("L_INFO", "$ci|log|Correcting NATed contact in registration\n");
@@ -50,11 +54,18 @@ route[HANDLE_REGISTER]
         #!endif
 
         if (is_present_hf("Authorization")) {
+
+           if (!route(PREVENT_BRUTEFORCE)) {
+                auth_challenge("$fd", "0");
+                exit;
+            }
+
             if ($sht(auth_cache=>$Au) != $null && pv_auth_check("$fd", "$sht(auth_cache=>$Au)", "0", "0")) {
                 xlog("L_INFO", "$ci|log|Authenticated $Au via cached SIP creds\n");
             } else {
                 ## RABBITMQ - Credentials fetch
                 if (!auth_check("$fd", "subscriber", "1")) {
+                    route(FAILED_AUTH_COUNT);
                     auth_challenge("$fd", "0");
                     xlog("L_INFO", "$ci|log|Issued new auth challenge to failed registration attempt\n");
                     exit;
@@ -77,4 +88,42 @@ route[HANDLE_REGISTER]
     }
 }
 
-## vim:set tabstop=4 softtabstop=4 shiftwidth=4 expandtab
+# AUTH: check to see if user if present in failed_auth_hash
+route[PREVENT_BRUTEFORCE]
+{
+    if($sht(failed_auth_hash=>$Au::count) >= 2) {
+        $var(exp) = $Ts - 120;
+        if($sht(failed_auth_hash=>$Au::last) > $var(exp)){
+            xlog("L_ERR", "Possible password brute force, from $ct on user $Au");
+            return(-1);
+        } else {
+            $sht(failed_auth_hash=>$Au::count) = 0;
+        }
+    }
+    return(1);
+}
+
+
+#AUTH: add to failed_auth_hash in case of authentication password error
+route[FAILED_AUTH_COUNT]
+{
+    if ($rc == -2) {
+        if($sht(failed_auth_hash=>$Au::count) == $null) {
+            $sht(failed_auth_hash=>$Au::count) = 0;
+        }
+        $sht(failed_auth_hash=>$Au::count) = $sht(failed_auth_hash=>$Au::count) + 1;
+        $sht(failed_auth_hash=>$Au::last) = $Ts;
+    }
+}
+
+route[DOMAIN_FORMAT_CHECK]
+{
+    if ($rd =~ "([0-9]{1,3})\.([0-9]{1,3})\.([0-9]{1,3})\.([0-9]{1,3})" ||
+        $td =~ "([0-9]{1,3})\.([0-9]{1,3})\.([0-9]{1,3})\.([0-9]{1,3}" ) {
+        send_reply("403", "Forbidden");
+        exit;
+    }
+
+}
+
+# vim:tabstop=4 softtabstop=4 shiftwidth=4 expandtab