diff --git a/app/modules/connections/edit.php b/app/modules/connections/edit.php
index 331eb86..40fe688 100644
--- a/app/modules/connections/edit.php
+++ b/app/modules/connections/edit.php
@@ -77,6 +77,9 @@ $isEndpointAllowed = static function (string $type, int $id) use ($occupiedByTyp
     if ($id <= 0) {
         return false;
     }
+    if ($type === 'outlet') {
+        return true;
+    }
     if ($type === $portAType && $id === $portAId) {
         return true;
     }
diff --git a/app/modules/connections/save.php b/app/modules/connections/save.php
index cd001c4..c6f3aa9 100644
--- a/app/modules/connections/save.php
+++ b/app/modules/connections/save.php
@@ -74,31 +74,73 @@ $otherConnections = $sql->get(
     [$connId]
 );
 
-$isEndpointUsed = static function (string $endpointType, int $endpointId) use ($otherConnections, $normalizePortType): bool {
+$endpointUsage = [];
+$trackUsage = static function (string $endpointType, int $endpointId, string $otherType) use (&$endpointUsage): void {
     if ($endpointId <= 0) {
-        return false;
+        return;
     }
-    foreach ((array)$otherConnections as $row) {
-        $typeA = $normalizePortType((string)($row['port_a_type'] ?? ''));
-        $idA = (int)($row['port_a_id'] ?? 0);
-        if ($typeA === $endpointType && $idA === $endpointId) {
-            return true;
-        }
-
-        $typeB = $normalizePortType((string)($row['port_b_type'] ?? ''));
-        $idB = (int)($row['port_b_id'] ?? 0);
-        if ($typeB === $endpointType && $idB === $endpointId) {
-            return true;
+    if (!isset($endpointUsage[$endpointType][$endpointId])) {
+        $endpointUsage[$endpointType][$endpointId] = [
+            'total' => 0,
+            'patchpanel' => 0,
+            'other' => 0,
+        ];
+    }
+    $endpointUsage[$endpointType][$endpointId]['total']++;
+    if ($endpointType === 'outlet') {
+        if ($otherType === 'patchpanel') {
+            $endpointUsage[$endpointType][$endpointId]['patchpanel']++;
+        } else {
+            $endpointUsage[$endpointType][$endpointId]['other']++;
         }
     }
-    return false;
 };
 
-if ($isEndpointUsed($portAType, $portAId)) {
-    $errors[] = "Port an Endpunkt A ist bereits in Verwendung";
+foreach ((array)$otherConnections as $row) {
+    $typeA = $normalizePortType((string)($row['port_a_type'] ?? ''));
+    $typeB = $normalizePortType((string)($row['port_b_type'] ?? ''));
+    $idA = (int)($row['port_a_id'] ?? 0);
+    $idB = (int)($row['port_b_id'] ?? 0);
+
+    $trackUsage($typeA, $idA, $typeB);
+    $trackUsage($typeB, $idB, $typeA);
 }
-if ($isEndpointUsed($portBType, $portBId)) {
-    $errors[] = "Port an Endpunkt B ist bereits in Verwendung";
+
+$validateEndpointUsage = static function (string $endpointType, int $endpointId, string $otherType, string $label) use ($endpointUsage): ?string {
+    if ($endpointId <= 0) {
+        return null;
+    }
+
+    $stats = $endpointUsage[$endpointType][$endpointId] ?? ['total' => 0, 'patchpanel' => 0, 'other' => 0];
+    if ((int)$stats['total'] <= 0) {
+        return null;
+    }
+
+    if ($endpointType !== 'outlet') {
+        return $label . " ist bereits in Verwendung";
+    }
+
+    if ($otherType === 'patchpanel') {
+        if ((int)$stats['patchpanel'] > 0) {
+            return $label . " hat bereits eine Patchpanel-Verbindung";
+        }
+        return null;
+    }
+
+    if ((int)$stats['other'] > 0) {
+        return $label . " hat bereits eine Endgeraete-Verbindung";
+    }
+    return null;
+};
+
+$errorA = $validateEndpointUsage($portAType, $portAId, $portBType, 'Port an Endpunkt A');
+if ($errorA !== null) {
+    $errors[] = $errorA;
+}
+
+$errorB = $validateEndpointUsage($portBType, $portBId, $portAType, 'Port an Endpunkt B');
+if ($errorB !== null) {
+    $errors[] = $errorB;
 }
 
 if (!empty($errors)) {