diff --git a/includes/polling/netstats-icmp.inc.php b/includes/polling/netstats-icmp.inc.php
index 9bb3929182..0136611120 100755
--- a/includes/polling/netstats-icmp.inc.php
+++ b/includes/polling/netstats-icmp.inc.php
@@ -35,7 +35,7 @@ if ($device['os'] != "Snom")
     {
        $value = $data_array[0][$oid];
     } else {
-      $value = "0";
+      $value = "U";
     }
     $rrdupdate .= ":$value";
   }
diff --git a/includes/polling/netstats-ip.inc.php b/includes/polling/netstats-ip.inc.php
index c505be5cc7..90b1b02a5f 100755
--- a/includes/polling/netstats-ip.inc.php
+++ b/includes/polling/netstats-ip.inc.php
@@ -33,7 +33,7 @@ if ($device['os'] != "Snom")
     {
       $value = $data[0][$oid];
     } else {
-      $value = "0";
+      $value = "U";
     }
     $rrdupdate .= ":$value";
   }
diff --git a/includes/polling/netstats-snmp.inc.php b/includes/polling/netstats-snmp.inc.php
index 56d5e28ecf..1adc18337e 100755
--- a/includes/polling/netstats-snmp.inc.php
+++ b/includes/polling/netstats-snmp.inc.php
@@ -33,7 +33,7 @@ if ($device['os'] != "Snom")
     {
        $value = $data_array[0][$oid];
     } else {
-      $value = "0";
+      $value = "U";
     }
     $rrdupdate .= ":$value";
   }
diff --git a/includes/polling/netstats-tcp.inc.php b/includes/polling/netstats-tcp.inc.php
index 7c5531d9f0..30336f6064 100755
--- a/includes/polling/netstats-tcp.inc.php
+++ b/includes/polling/netstats-tcp.inc.php
@@ -37,7 +37,7 @@ if ($device['os'] != "Snom")
     {
       $value = $data[0][$oid];
     } else {
-      $value = "0";
+      $value = "U";
     }
     $rrdupdate .= ":$value";
   }
diff --git a/includes/polling/netstats-udp.inc.php b/includes/polling/netstats-udp.inc.php
index bb55216373..1477839a9e 100755
--- a/includes/polling/netstats-udp.inc.php
+++ b/includes/polling/netstats-udp.inc.php
@@ -32,7 +32,7 @@ if ($device['os'] != "Snom")
     {
       $value = $data[0][$oid];
     } else {
-      $value = "0";
+      $value = "U";
     }
     $rrdupdate .= ":$value";
   }