diff --git a/openflow_input/bsn_pdu b/openflow_input/bsn_pdu
index c2735de..790604f 100644
--- a/openflow_input/bsn_pdu
+++ b/openflow_input/bsn_pdu
@@ -30,6 +30,12 @@
 
 #version any
 
+// When the slot_num field has this value, the message applies
+// to all currently used slots on the switch for the given port
+enum of_bsn_pdu_slot_num_t(wire_type=uint8_t, complete=False) {
+    BSN_PDU_SLOT_NUM_ANY = 0xff
+};
+
 struct of_bsn_pdu_tx_request : of_bsn_header {
     uint8_t version;
     uint8_t type == 4;
@@ -39,6 +45,8 @@
     uint32_t subtype == 31;
     uint32_t tx_interval_ms;
     of_port_no_t port_no;
+    uint8_t slot_num;
+    pad(3);
     of_octets_t data;
 };
 
@@ -61,6 +69,8 @@
     uint32_t subtype == 33;
     uint32_t timeout_ms;
     of_port_no_t port_no;
+    uint8_t slot_num;
+    pad(3);
     of_octets_t data;
 };
 
@@ -82,4 +92,5 @@
     uint32_t experimenter == 0x5c16c7;
     uint32_t subtype == 35;
     of_port_no_t port_no;
+    uint8_t slot_num;
 };