diff --git a/doc/openapi/components/schemas/config/nodes/opal_orchestra.yaml b/doc/openapi/components/schemas/config/nodes/opal_orchestra.yaml
index 302462e29..816bbee25 100644
--- a/doc/openapi/components/schemas/config/nodes/opal_orchestra.yaml
+++ b/doc/openapi/components/schemas/config/nodes/opal_orchestra.yaml
@@ -27,20 +27,20 @@ allOf:
         The path to the DDF file that describes the data exchanged in the specified domain.
 
     connect_timeout:
-      $ref: ../../duration.yaml
+      $ref: ../duration.yaml
       default: 5s
       description: >-
         The duration after which a failed connection attempt times out.
 
     flag_delay:
-      $ref: ../../duration.yaml
+      $ref: ../duration.yaml
       default: 0s
       description: >-
         Forces the local Orchestra communication to be made with flags instead of semaphores when using an external communication process.
         Flags are recommended for better performance: they are faster but also more CPU-consuming.
 
     flag_delay_tool:
-      $ref: ../../duration.yaml
+      $ref: ../duration.yaml
       description: >-
         Forces the local Orchestra communication to be made with flags instead of semaphores when using an external communication process.
         Flags are recommended for better performance: they are faster but also more CPU-consuming.
diff --git a/doc/openapi/components/schemas/config/nodes/opal_orchestra_connection.yaml b/doc/openapi/components/schemas/config/nodes/opal_orchestra_connection.yaml
index 9f3588499..f27b2b9f8 100644
--- a/doc/openapi/components/schemas/config/nodes/opal_orchestra_connection.yaml
+++ b/doc/openapi/components/schemas/config/nodes/opal_orchestra_connection.yaml
@@ -13,6 +13,6 @@ properties:
 discriminator:
   propertyName: type
   mapping:
-    local: opal_orchestra_connection_local.yaml
-    remote: opal_orchestra_connection_remote.yaml
-    dolphin: opal_orchestra_connection_dolphin.yaml
+    local: ./opal_orchestra_connection_local.yaml
+    remote: ./opal_orchestra_connection_remote.yaml
+    dolphin: ./opal_orchestra_connection_dolphin.yaml
diff --git a/etc/labs/lab19.conf b/etc/labs/lab19.conf
new file mode 100644
index 000000000..aac280309
--- /dev/null
+++ b/etc/labs/lab19.conf
@@ -0,0 +1,42 @@
+nodes = {
+    udp_node = {
+        type = "socket"
+        layer = "udp"
+        format = "protobuf"
+
+        in = {
+            address = "*:12000"
+
+            signals = {
+                count = 5   # expected incoming sample, send back from Python client, repeats samples if values in signal is smaller
+                type = "float"
+            }
+            hooks = (
+            {
+                type = "print"
+            }
+        )
+        },
+        out = {
+            address = "127.0.0.1:12001"
+        }
+    }
+    signal = {
+        type = "signal"
+
+        signal = "mixed"
+        values = 5  # values per sample
+        limit = 3   # emit limited number of samples
+    }
+}
+
+paths = (
+    {
+        in = "signal"
+        out = "udp_node"
+    },
+    {
+	in = "udp_node"
+    }
+
+)