diff --git a/lib/ipsec/iph.h b/lib/ipsec/iph.h
index 2d223199ac..c5c213a2b4 100644
--- a/lib/ipsec/iph.h
+++ b/lib/ipsec/iph.h
@@ -251,6 +251,7 @@ update_tun_outb_l3hdr(const struct rte_ipsec_sa *sa, void *outh,
 {
 	struct rte_ipv4_hdr *v4h;
 	struct rte_ipv6_hdr *v6h;
+	struct rte_udp_hdr *udph;
 	uint8_t is_outh_ipv4;
 
 	if (sa->type & RTE_IPSEC_SATP_MODE_TUNLV4) {
@@ -258,11 +259,27 @@ update_tun_outb_l3hdr(const struct rte_ipsec_sa *sa, void *outh,
 		v4h = outh;
 		v4h->packet_id = pid;
 		v4h->total_length = rte_cpu_to_be_16(plen - l2len);
+
+		if (sa->type & RTE_IPSEC_SATP_NATT_ENABLE) {
+			udph = (struct rte_udp_hdr *)(v4h + 1);
+			udph->dst_port = sa->natt.dport;
+			udph->src_port = sa->natt.sport;
+			udph->dgram_len = rte_cpu_to_be_16(plen - l2len -
+				(sizeof(*v4h) + sizeof(*udph)));
+		}
 	} else {
 		is_outh_ipv4 = 0;
 		v6h = outh;
 		v6h->payload_len = rte_cpu_to_be_16(plen - l2len -
 				sizeof(*v6h));
+
+		if (sa->type & RTE_IPSEC_SATP_NATT_ENABLE) {
+			udph = (struct rte_udp_hdr *)(v6h + 1);
+			udph->dst_port = sa->natt.dport;
+			udph->src_port = sa->natt.sport;
+			udph->dgram_len = rte_cpu_to_be_16(plen - l2len -
+				(sizeof(*v6h) + sizeof(*udph)));
+		}
 	}
 
 	if (sa->type & TUN_HDR_MSK)
diff --git a/lib/ipsec/rte_ipsec_sa.h b/lib/ipsec/rte_ipsec_sa.h
index cf51ad8338..40d1e70d45 100644
--- a/lib/ipsec/rte_ipsec_sa.h
+++ b/lib/ipsec/rte_ipsec_sa.h
@@ -76,6 +76,7 @@ struct rte_ipsec_sa_prm {
  * - inbound/outbound
  * - mode (TRANSPORT/TUNNEL)
  * - for TUNNEL outer IP version (IPv4/IPv6)
+ * - NAT-T UDP encapsulated (TUNNEL mode only)
  * - are SA SQN operations 'atomic'
  * - ESN enabled/disabled
  * ...
@@ -86,7 +87,8 @@ enum {
 	RTE_SATP_LOG2_PROTO,
 	RTE_SATP_LOG2_DIR,
 	RTE_SATP_LOG2_MODE,
-	RTE_SATP_LOG2_SQN = RTE_SATP_LOG2_MODE + 2,
+	RTE_SATP_LOG2_NATT = RTE_SATP_LOG2_MODE + 2,
+	RTE_SATP_LOG2_SQN,
 	RTE_SATP_LOG2_ESN,
 	RTE_SATP_LOG2_ECN,
 	RTE_SATP_LOG2_DSCP
@@ -109,6 +111,10 @@ enum {
 #define RTE_IPSEC_SATP_MODE_TUNLV4	(1ULL << RTE_SATP_LOG2_MODE)
 #define RTE_IPSEC_SATP_MODE_TUNLV6	(2ULL << RTE_SATP_LOG2_MODE)
 
+#define RTE_IPSEC_SATP_NATT_MASK	(1ULL << RTE_SATP_LOG2_NATT)
+#define RTE_IPSEC_SATP_NATT_DISABLE	(0ULL << RTE_SATP_LOG2_NATT)
+#define RTE_IPSEC_SATP_NATT_ENABLE	(1ULL << RTE_SATP_LOG2_NATT)
+
 #define RTE_IPSEC_SATP_SQN_MASK		(1ULL << RTE_SATP_LOG2_SQN)
 #define RTE_IPSEC_SATP_SQN_RAW		(0ULL << RTE_SATP_LOG2_SQN)
 #define RTE_IPSEC_SATP_SQN_ATOM		(1ULL << RTE_SATP_LOG2_SQN)
diff --git a/lib/ipsec/sa.c b/lib/ipsec/sa.c
index 2ecbbce0a4..8e369e4618 100644
--- a/lib/ipsec/sa.c
+++ b/lib/ipsec/sa.c
@@ -217,6 +217,10 @@ fill_sa_type(const struct rte_ipsec_sa_prm *prm, uint64_t *type)
 	} else
 		return -EINVAL;
 
+	/* check for UDP encapsulation flag */
+	if (prm->ipsec_xform.options.udp_encap == 1)
+		tp |= RTE_IPSEC_SATP_NATT_ENABLE;
+
 	/* check for ESN flag */
 	if (prm->ipsec_xform.options.esn == 0)
 		tp |= RTE_IPSEC_SATP_ESN_DISABLE;
@@ -372,7 +376,8 @@ esp_sa_init(struct rte_ipsec_sa *sa, const struct rte_ipsec_sa_prm *prm,
 	const struct crypto_xform *cxf)
 {
 	static const uint64_t msk = RTE_IPSEC_SATP_DIR_MASK |
-				RTE_IPSEC_SATP_MODE_MASK;
+				RTE_IPSEC_SATP_MODE_MASK |
+				RTE_IPSEC_SATP_NATT_MASK;
 
 	if (prm->ipsec_xform.options.ecn)
 		sa->tos_mask |= RTE_IPV4_HDR_ECN_MASK;
@@ -475,10 +480,16 @@ esp_sa_init(struct rte_ipsec_sa *sa, const struct rte_ipsec_sa_prm *prm,
 	case (RTE_IPSEC_SATP_DIR_IB | RTE_IPSEC_SATP_MODE_TRANS):
 		esp_inb_init(sa);
 		break;
+	case (RTE_IPSEC_SATP_DIR_OB | RTE_IPSEC_SATP_MODE_TUNLV4 |
+			RTE_IPSEC_SATP_NATT_ENABLE):
+	case (RTE_IPSEC_SATP_DIR_OB | RTE_IPSEC_SATP_MODE_TUNLV6 |
+			RTE_IPSEC_SATP_NATT_ENABLE):
 	case (RTE_IPSEC_SATP_DIR_OB | RTE_IPSEC_SATP_MODE_TUNLV4):
 	case (RTE_IPSEC_SATP_DIR_OB | RTE_IPSEC_SATP_MODE_TUNLV6):
 		esp_outb_tun_init(sa, prm);
 		break;
+	case (RTE_IPSEC_SATP_DIR_OB | RTE_IPSEC_SATP_MODE_TRANS |
+			RTE_IPSEC_SATP_NATT_ENABLE):
 	case (RTE_IPSEC_SATP_DIR_OB | RTE_IPSEC_SATP_MODE_TRANS):
 		esp_outb_init(sa, 0);
 		break;
diff --git a/lib/ipsec/sa.h b/lib/ipsec/sa.h
index 5e237f3525..3f38921eb3 100644
--- a/lib/ipsec/sa.h
+++ b/lib/ipsec/sa.h
@@ -101,6 +101,10 @@ struct rte_ipsec_sa {
 		uint64_t msk;
 		uint64_t val;
 	} tx_offload;
+	struct {
+		uint16_t sport;
+		uint16_t dport;
+	} natt;
 	uint32_t salt;
 	uint8_t algo_type;
 	uint8_t proto;    /* next proto */
