diff --git a/pipelines/fabric/src/main/resources/include/header.p4 b/pipelines/fabric/src/main/resources/include/header.p4
index 6cff586..6a48452 100644
--- a/pipelines/fabric/src/main/resources/include/header.p4
+++ b/pipelines/fabric/src/main/resources/include/header.p4
@@ -55,7 +55,8 @@
 header ipv4_t {
     bit<4> version;
     bit<4> ihl;
-    bit<8> diffserv;
+    bit<6> dscp;
+    bit<2> ecn;
     bit<16> total_len;
     bit<16> identification;
     bit<3> flags;
@@ -131,7 +132,7 @@
 }
 
 struct spgw_meta_t {
-    bool              do_spgw;
+    bit<1>            do_spgw;
     direction_t       direction;
     bit<16>           ipv4_len;
     bit<32>           teid;
@@ -147,6 +148,78 @@
 }
 #endif // WITH_SPGW
 
+#ifdef WITH_INT_TRANSIT
+
+header intl4_shim_t {
+    bit<8> int_type;
+    bit<8> rsvd1;
+    bit<8> len;
+    bit<8> rsvd2;
+}
+
+// INT headers
+header int_header_t {
+    bit<4> ver;
+    bit<2> rep;
+    bit<1> c;
+    bit<1> e;
+    bit<3> rsvd1;
+    bit<5> ins_cnt;
+    bit<8> max_hop_cnt;
+    bit<8> total_hop_cnt;
+    bit<4> instruction_mask_0003; // split the bits for lookup
+    bit<4> instruction_mask_0407;
+    bit<4> instruction_mask_0811;
+    bit<4> instruction_mask_1215;
+    bit<16> rsvd2;
+}
+
+// INT meta-value headers - different header for each value type
+header int_switch_id_t {
+    bit<32> switch_id;
+}
+
+header int_port_ids_t {
+    bit<16> ingress_port_id;
+    bit<16> egress_port_id;
+}
+
+header int_hop_latency_t {
+    bit<32> hop_latency;
+}
+
+header int_q_occupancy_t {
+    bit<8> q_id;
+    bit<24> q_occupancy;
+}
+
+header int_ingress_tstamp_t {
+    bit<32> ingress_tstamp;
+}
+
+header int_egress_tstamp_t {
+    bit<32> egress_tstamp;
+}
+
+header int_q_congestion_t {
+    bit<8> q_id;
+    bit<24> q_congestion;
+}
+
+header int_egress_port_tx_util_t {
+    bit<32> egress_port_tx_util;
+}
+
+// switch internal variables for INT logic implementation
+struct int_metadata_t {
+    bit<16> insert_byte_cnt;
+    bit<8> int_hdr_word_len;
+    bit<32> switch_id;
+    bit<5> ins_cnt_tmp;
+}
+
+#endif // WITH_INT_TRANSIT
+
 //Custom metadata definition
 struct fabric_metadata_t {
     fwd_type_t fwd_type;
@@ -159,6 +232,9 @@
 #ifdef WITH_SPGW
     spgw_meta_t spgw;
 #endif // WITH_SPGW
+#ifdef WITH_INT_TRANSIT
+    int_metadata_t int_metadata;
+#endif // WITH_INT_TRANSIT
 }
 
 struct parsed_headers_t {
@@ -180,6 +256,18 @@
     icmp_t icmp;
     packet_out_header_t packet_out;
     packet_in_header_t packet_in;
+#ifdef WITH_INT_TRANSIT
+    intl4_shim_t intl4_shim;
+    int_header_t int_header;
+    int_switch_id_t int_switch_id;
+    int_port_ids_t int_port_ids;
+    int_hop_latency_t int_hop_latency;
+    int_q_occupancy_t int_q_occupancy;
+    int_ingress_tstamp_t int_ingress_tstamp;
+    int_egress_tstamp_t int_egress_tstamp;
+    int_q_congestion_t int_q_congestion;
+    int_egress_port_tx_util_t int_egress_port_tx_util;
+#endif // WITH_INT_TRANSIT
 }
 
 #endif