Issue-ID: VFC-1504
Signed-off-by: hewei-cmss <hewei@cmss.chinamobile.com>
Change-Id: Ica1f33261c25e3fe924bfc8e8c9d446bd714266d
     nsDescription = serializers.CharField(
         help_text="Description of NS",
         required=True,
-        allow_null=True)
+        allow_null=True,
+        allow_blank=True)
 
         required=True)
     nsInstanceDescription = serializers.CharField(
         help_text="Human readable description of the NS instance.",
-        required=True)
+        required=True,
+        allow_null=True,
+        allow_blank=True)
     nsdId = serializers.CharField(
         help_text="Identifier of the NSD on which the NS instance is based.",
         required=True)