diff --git a/app/test/test_pdcp.c b/app/test/test_pdcp.c
index 10a383ddd7..1e74147579 100644
--- a/app/test/test_pdcp.c
+++ b/app/test/test_pdcp.c
@@ -4,6 +4,7 @@
 
 #include <rte_malloc.h>
 #include <rte_pdcp.h>
+#include <rte_pdcp_hdr.h>
 
 #include "test.h"
 #include "test_cryptodev.h"
@@ -19,17 +20,17 @@ struct pdcp_testsuite_params {
 
 static struct pdcp_testsuite_params testsuite_params;
 
-#define PDCP_MAX_TEST_INPUT_LEN 2048
+#define PDCP_MAX_TEST_DATA_LEN 2048
 
 struct pdcp_test_conf {
 	struct rte_pdcp_entity_conf entity;
 	struct rte_crypto_sym_xform c_xfrm;
 	struct rte_crypto_sym_xform a_xfrm;
 	bool is_integrity_protected;
-	uint8_t input[PDCP_MAX_TEST_INPUT_LEN];
+	uint8_t input[PDCP_MAX_TEST_DATA_LEN];
 	uint32_t input_len;
-	const uint8_t *expected;
-	uint32_t expected_len;
+	uint8_t output[PDCP_MAX_TEST_DATA_LEN];
+	uint32_t output_len;
 };
 
 static inline int
@@ -38,6 +39,19 @@ pdcp_hdr_size_get(enum rte_security_pdcp_sn_size sn_size)
 	return RTE_ALIGN_MUL_CEIL(sn_size, 8) / 8;
 }
 
+static int
+pktmbuf_read_into(const struct rte_mbuf *m, void *buf, size_t buf_len)
+{
+	if (m->pkt_len > buf_len)
+		return -ENOMEM;
+
+	const void *read = rte_pktmbuf_read(m, 0, m->pkt_len, buf);
+	if (read != NULL && read != buf)
+		memcpy(buf, read, m->pkt_len);
+
+	return 0;
+}
+
 static int
 cryptodev_init(int dev_id)
 {
@@ -300,14 +314,45 @@ process_crypto_request(uint8_t dev_id, struct rte_crypto_op *op)
 	return op;
 }
 
+static uint32_t
+pdcp_sn_from_raw_get(const void *data, enum rte_security_pdcp_sn_size size)
+{
+	uint32_t sn = 0;
+
+	if (size == RTE_SECURITY_PDCP_SN_SIZE_12) {
+		sn = rte_cpu_to_be_16(*(const uint16_t *)data);
+		sn = sn & 0xfff;
+	} else if (size == RTE_SECURITY_PDCP_SN_SIZE_18) {
+		sn = rte_cpu_to_be_32(*(const uint32_t *)data);
+		sn = (sn & 0x3ffff00) >> 8;
+	}
+
+	return sn;
+}
+
+static void
+pdcp_sn_to_raw_set(void *data, uint32_t sn, int size)
+{
+	if (size == RTE_SECURITY_PDCP_SN_SIZE_12) {
+		struct rte_pdcp_up_data_pdu_sn_12_hdr *pdu_hdr = data;
+		pdu_hdr->sn_11_8 = ((sn & 0xf00) >> 8);
+		pdu_hdr->sn_7_0 = (sn & 0xff);
+	} else if (size == RTE_SECURITY_PDCP_SN_SIZE_18) {
+		struct rte_pdcp_up_data_pdu_sn_18_hdr *pdu_hdr = data;
+		pdu_hdr->sn_17_16 = ((sn & 0x30000) >> 16);
+		pdu_hdr->sn_15_8 = ((sn & 0xff00) >> 8);
+		pdu_hdr->sn_7_0 = (sn & 0xff);
+	}
+}
+
 static int
 create_test_conf_from_index(const int index, struct pdcp_test_conf *conf)
 {
 	const struct pdcp_testsuite_params *ts_params = &testsuite_params;
 	struct rte_crypto_sym_xform c_xfrm, a_xfrm;
-	uint32_t hfn, sn, count = 0;
+	uint32_t hfn, sn, expected_len, count = 0;
+	uint8_t *data, *expected;
 	int pdcp_hdr_sz;
-	uint8_t *data;
 
 	memset(conf, 0, sizeof(*conf));
 	memset(&c_xfrm, 0, sizeof(c_xfrm));
@@ -326,6 +371,7 @@ create_test_conf_from_index(const int index, struct pdcp_test_conf *conf)
 		conf->entity.pdcp_xfrm.pkt_dir = RTE_SECURITY_PDCP_DOWNLINK;
 
 	conf->entity.pdcp_xfrm.sn_size = pdcp_test_data_sn_size[index];
+	/* Zero initialize unsupported flags */
 	conf->entity.pdcp_xfrm.hfn_threshold = 0;
 	conf->entity.pdcp_xfrm.hfn_ovrd = 0;
 	conf->entity.pdcp_xfrm.sdap_enabled = 0;
@@ -414,14 +460,7 @@ create_test_conf_from_index(const int index, struct pdcp_test_conf *conf)
 	    pdcp_test_params[index].domain == RTE_SECURITY_PDCP_MODE_DATA) {
 		data = pdcp_test_data_in[index];
 		hfn = pdcp_test_hfn[index] << pdcp_test_data_sn_size[index];
-		sn = 0;
-		if (pdcp_test_data_sn_size[index] == RTE_SECURITY_PDCP_SN_SIZE_12) {
-			sn = rte_cpu_to_be_16(*(uint16_t *)data);
-			sn = sn & 0xfff;
-		} else if (pdcp_test_data_sn_size[index] == RTE_SECURITY_PDCP_SN_SIZE_18) {
-			sn = rte_cpu_to_be_32(*(uint32_t *)data);
-			sn = (sn & 0x3ffff00) >> 8;
-		}
+		sn = pdcp_sn_from_raw_get(data, pdcp_test_data_sn_size[index]);
 		count = hfn | sn;
 	}
 	conf->entity.count = count;
@@ -448,29 +487,32 @@ create_test_conf_from_index(const int index, struct pdcp_test_conf *conf)
 	}
 
 	if (conf->entity.pdcp_xfrm.pkt_dir == RTE_SECURITY_PDCP_UPLINK)
-		conf->expected = pdcp_test_data_out[index];
+		expected = pdcp_test_data_out[index];
 	else
-		conf->expected = pdcp_test_data_in[index];
+		expected = pdcp_test_data_in[index];
 
 	/* Calculate expected packet length */
-	conf->expected_len = pdcp_test_data_in_len[index];
+	expected_len = pdcp_test_data_in_len[index];
 
 	/* In DL processing, PDCP header would be stripped */
 	if (conf->entity.pdcp_xfrm.pkt_dir == RTE_SECURITY_PDCP_DOWNLINK) {
-		conf->expected += pdcp_hdr_sz;
-		conf->expected_len -= pdcp_hdr_sz;
+		expected += pdcp_hdr_sz;
+		expected_len -= pdcp_hdr_sz;
 	}
 
 	/* In UL processing with integrity protection, MAC would be added */
 	if (conf->is_integrity_protected &&
 	    conf->entity.pdcp_xfrm.pkt_dir == RTE_SECURITY_PDCP_UPLINK)
-		conf->expected_len += 4;
+		expected_len += 4;
+
+	memcpy(conf->output, expected, expected_len);
+	conf->output_len = expected_len;
 
 	return 0;
 }
 
 static int
-test_attempt_single(const struct pdcp_test_conf *t_conf)
+test_attempt_single(struct pdcp_test_conf *t_conf)
 {
 	const struct pdcp_testsuite_params *ts_params = &testsuite_params;
 	struct rte_mbuf *mbuf, *mb, **out_mb = NULL;
@@ -584,9 +626,17 @@ test_attempt_single(const struct pdcp_test_conf *t_conf)
 		goto mbuf_free;
 	}
 
-	ret = pdcp_known_vec_verify(mbuf, t_conf->expected, t_conf->expected_len);
-	if (ret)
-		goto mbuf_free;
+	/* If expected output provided - verify, else - store for future use */
+	if (t_conf->output_len) {
+		ret = pdcp_known_vec_verify(mbuf, t_conf->output, t_conf->output_len);
+		if (ret)
+			goto mbuf_free;
+	} else {
+		ret = pktmbuf_read_into(mbuf, t_conf->output, PDCP_MAX_TEST_DATA_LEN);
+		if (ret)
+			goto mbuf_free;
+		t_conf->output_len = mbuf->pkt_len;
+	}
 
 	ret = rte_pdcp_entity_suspend(pdcp_entity, out_mb);
 	if (ret) {
@@ -609,6 +659,195 @@ test_attempt_single(const struct pdcp_test_conf *t_conf)
 	return TEST_FAILED;
 }
 
+static void
+uplink_to_downlink_convert(const struct pdcp_test_conf *ul_cfg,
+			   struct pdcp_test_conf *dl_cfg)
+{
+	assert(ul_cfg->entity.pdcp_xfrm.pkt_dir == RTE_SECURITY_PDCP_UPLINK);
+
+	memcpy(dl_cfg, ul_cfg, sizeof(*dl_cfg));
+	dl_cfg->entity.pdcp_xfrm.pkt_dir = RTE_SECURITY_PDCP_DOWNLINK;
+	dl_cfg->entity.reverse_iv_direction = false;
+
+	if (dl_cfg->is_integrity_protected) {
+		dl_cfg->entity.crypto_xfrm = &dl_cfg->c_xfrm;
+
+		dl_cfg->c_xfrm.cipher.op = RTE_CRYPTO_CIPHER_OP_DECRYPT;
+		dl_cfg->c_xfrm.next = &dl_cfg->a_xfrm;
+
+		dl_cfg->a_xfrm.auth.op = RTE_CRYPTO_AUTH_OP_VERIFY;
+		dl_cfg->a_xfrm.next = NULL;
+	} else {
+		dl_cfg->entity.crypto_xfrm = &dl_cfg->c_xfrm;
+		dl_cfg->c_xfrm.next = NULL;
+		dl_cfg->c_xfrm.cipher.op = RTE_CRYPTO_CIPHER_OP_DECRYPT;
+	}
+
+	memcpy(dl_cfg->input, ul_cfg->output, ul_cfg->output_len);
+	dl_cfg->input_len = ul_cfg->output_len;
+
+	memcpy(dl_cfg->output, ul_cfg->input, ul_cfg->input_len);
+	dl_cfg->output_len = ul_cfg->input_len;
+}
+
+/*
+ * According to ETSI TS 138 323 V17.1.0, Section 5.2.2.1,
+ * SN could be divided into following ranges,
+ * relatively to current value of RX_DELIV state:
+ * +-------------+-------------+-------------+-------------+
+ * |  -Outside   |  -Window    |   +Window   |  +Outside   |
+ * |   (valid)   |  (Invalid)  |   (Valid)   |  (Invalid)  |
+ * +-------------+-------------^-------------+-------------+
+ *                             |
+ *                             v
+ *                        SN(RX_DELIV)
+ */
+enum sn_range_type {
+	SN_RANGE_MINUS_OUTSIDE,
+	SN_RANGE_MINUS_WINDOW,
+	SN_RANGE_PLUS_WINDOW,
+	SN_RANGE_PLUS_OUTSIDE,
+};
+
+#define PDCP_SET_COUNT(hfn, sn, size) ((hfn << size) | (sn & ((1 << size) - 1)))
+
+/*
+ * Take uplink test case as base, modify RX_DELIV in state and SN in input
+ */
+static int
+test_sn_range_type_with_config(enum sn_range_type type, struct pdcp_test_conf *conf)
+{
+	uint32_t rx_deliv_hfn, rx_deliv_sn, rx_deliv, new_hfn, new_sn;
+	const int domain = conf->entity.pdcp_xfrm.domain;
+	struct pdcp_test_conf dl_conf;
+	int ret, expected_ret;
+
+	if (domain != RTE_SECURITY_PDCP_MODE_CONTROL && domain != RTE_SECURITY_PDCP_MODE_DATA)
+		return TEST_SKIPPED;
+
+	const uint32_t sn_size = conf->entity.pdcp_xfrm.sn_size;
+	/* According to formula(7.2.a Window_Size) */
+	const uint32_t window_size = 1 << (sn_size - 1);
+	/* Max value of SN that could fit in `sn_size` bits */
+	const uint32_t max_sn = (1 << sn_size) - 1;
+	const uint32_t shift = (max_sn - window_size) / 2;
+	/* Could be any number up to `shift` value */
+	const uint32_t default_sn = RTE_MIN(2u, shift);
+
+	/* Initialize HFN as non zero value, to be able check values before */
+	rx_deliv_hfn = 0xa;
+
+	switch (type) {
+	case SN_RANGE_PLUS_WINDOW:
+		/* Within window size, HFN stay same */
+		new_hfn = rx_deliv_hfn;
+		rx_deliv_sn = default_sn;
+		new_sn = rx_deliv_sn + 1;
+		expected_ret = TEST_SUCCESS;
+		break;
+	case SN_RANGE_MINUS_WINDOW:
+		/* Within window size, HFN stay same */
+		new_hfn = rx_deliv_hfn;
+		rx_deliv_sn = default_sn;
+		new_sn = rx_deliv_sn - 1;
+		expected_ret = TEST_FAILED;
+		break;
+	case SN_RANGE_PLUS_OUTSIDE:
+		/* RCVD_SN >= SN(RX_DELIV) + Window_Size */
+		new_hfn = rx_deliv_hfn - 1;
+		rx_deliv_sn = default_sn;
+		new_sn = rx_deliv_sn + window_size;
+		expected_ret = TEST_FAILED;
+		break;
+	case SN_RANGE_MINUS_OUTSIDE:
+		/* RCVD_SN < SN(RX_DELIV) - Window_Size */
+		new_hfn = rx_deliv_hfn + 1;
+		rx_deliv_sn = window_size + default_sn;
+		new_sn = rx_deliv_sn - window_size - 1;
+		expected_ret = TEST_SUCCESS;
+		break;
+	default:
+		return TEST_FAILED;
+	}
+
+	rx_deliv = PDCP_SET_COUNT(rx_deliv_hfn, rx_deliv_sn, sn_size);
+
+	/* Configure Uplink to generate expected, encrypted packet */
+	pdcp_sn_to_raw_set(conf->input, new_sn, conf->entity.pdcp_xfrm.sn_size);
+	conf->entity.reverse_iv_direction = true;
+	conf->entity.count = PDCP_SET_COUNT(new_hfn, new_sn, sn_size);
+	conf->output_len = 0;
+	ret = test_attempt_single(conf);
+	if (ret != TEST_SUCCESS)
+		return ret;
+
+	/* Flip configuration to downlink */
+	uplink_to_downlink_convert(conf, &dl_conf);
+	/* Modify the rx_deliv to verify the expected behaviour */
+	dl_conf.entity.count = rx_deliv;
+	ret = test_attempt_single(&dl_conf);
+	if (ret == TEST_SKIPPED)
+		return TEST_SKIPPED;
+	TEST_ASSERT_EQUAL(ret, expected_ret, "Unexpected result");
+
+	return TEST_SUCCESS;
+}
+
+static int
+test_sn_range_type(enum sn_range_type type)
+{
+	int i, ret, passed = 0;
+	struct pdcp_test_conf t_conf;
+
+	int nb_test = RTE_DIM(pdcp_test_params);
+
+	for (i = 0; i < nb_test; i++) {
+		create_test_conf_from_index(i, &t_conf);
+		if (t_conf.entity.pdcp_xfrm.pkt_dir == RTE_SECURITY_PDCP_DOWNLINK)
+			continue;
+		printf("[%03i] - %s", i, pdcp_test_params[i].name);
+		ret = test_sn_range_type_with_config(type, &t_conf);
+		if (ret == TEST_FAILED) {
+			printf(" - failed\n");
+			return ret;
+		} else if (ret == TEST_SKIPPED) {
+			printf(" - skipped\n");
+			continue;
+		}
+		printf(" - passed\n");
+		passed += 1;
+	}
+
+	printf("Passed: %i\n", passed);
+
+	return TEST_SUCCESS;
+}
+
+static int
+test_sn_plus_window(void)
+{
+	return test_sn_range_type(SN_RANGE_PLUS_WINDOW);
+}
+
+static int
+test_sn_minus_window(void)
+{
+	return test_sn_range_type(SN_RANGE_MINUS_WINDOW);
+}
+
+
+static int
+test_sn_plus_outside(void)
+{
+	return test_sn_range_type(SN_RANGE_PLUS_OUTSIDE);
+}
+
+static int
+test_sn_minus_outside(void)
+{
+	return test_sn_range_type(SN_RANGE_MINUS_OUTSIDE);
+}
+
 static int
 test_iterate_all(void)
 {
@@ -632,6 +871,7 @@ test_iterate_all(void)
 		printf(" - passed\n");
 		passed += 1;
 	}
+
 	printf("Passed: %i\n", passed);
 
 	return TEST_SUCCESS;
@@ -643,8 +883,52 @@ test_sample(void)
 	return test_iterate_all();
 }
 
-static struct unit_test_suite pdcp_testsuite  = {
-	.suite_name = "PDCP Unit Test Suite",
+static int
+test_combined(void)
+{
+	struct pdcp_test_conf ul_conf, dl_conf;
+	int ret, nb_test, i, passed = 0;
+
+	nb_test = RTE_DIM(pdcp_test_params);
+
+	for (i = 0; i < nb_test; i++) {
+		create_test_conf_from_index(i, &ul_conf);
+		if (ul_conf.entity.pdcp_xfrm.pkt_dir == RTE_SECURITY_PDCP_DOWNLINK)
+			continue;
+
+		ul_conf.entity.reverse_iv_direction = true;
+		ul_conf.output_len = 0;
+		printf("[%03i] - %s", i, pdcp_test_params[i].name);
+
+		ret = test_attempt_single(&ul_conf);
+		if (ret == TEST_FAILED) {
+			printf(" - failed\n");
+			return ret;
+		} else if (ret == TEST_SKIPPED) {
+			printf(" - skipped\n");
+			continue;
+		}
+
+		uplink_to_downlink_convert(&ul_conf, &dl_conf);
+		ret = test_attempt_single(&dl_conf);
+		if (ret == TEST_FAILED) {
+			printf(" - failed\n");
+			return ret;
+		} else if (ret == TEST_SKIPPED) {
+			printf(" - skipped\n");
+			continue;
+		}
+
+		printf(" - passed\n");
+		passed += 1;
+	}
+	printf("Passed: %i\n", passed);
+
+	return TEST_SUCCESS;
+}
+
+static struct unit_test_suite known_vector_cases  = {
+	.suite_name = "PDCP known vectors",
 	.setup = testsuite_setup,
 	.teardown = testsuite_teardown,
 	.unit_test_cases = {
@@ -654,10 +938,62 @@ static struct unit_test_suite pdcp_testsuite  = {
 	}
 };
 
+static struct unit_test_suite combined_mode_cases  = {
+	.suite_name = "PDCP combined mode",
+	.setup = testsuite_setup,
+	.teardown = testsuite_teardown,
+	.unit_test_cases = {
+		TEST_CASE_ST(ut_setup_pdcp, ut_teardown_pdcp,
+			test_combined),
+		TEST_CASES_END() /**< NULL terminate unit test array */
+	}
+};
+
+static struct unit_test_suite hfn_sn_test_cases  = {
+	.suite_name = "PDCP HFN/SN",
+	.setup = testsuite_setup,
+	.teardown = testsuite_teardown,
+	.unit_test_cases = {
+		TEST_CASE_ST(ut_setup_pdcp, ut_teardown_pdcp,
+			test_sn_plus_window),
+		TEST_CASE_ST(ut_setup_pdcp, ut_teardown_pdcp,
+			test_sn_minus_window),
+		TEST_CASE_ST(ut_setup_pdcp, ut_teardown_pdcp,
+			test_sn_plus_outside),
+		TEST_CASE_ST(ut_setup_pdcp, ut_teardown_pdcp,
+			test_sn_minus_outside),
+		TEST_CASES_END() /**< NULL terminate unit test array */
+	}
+};
+
 static int
 test_pdcp(void)
 {
-	return unit_test_suite_runner(&pdcp_testsuite);
+	int ret;
+
+	static struct unit_test_suite pdcp_testsuite  = {
+		.suite_name = "PDCP Unit Test Suite",
+		.unit_test_cases = {TEST_CASES_END()},
+	};
+
+	struct unit_test_suite *static_suites[] = {
+		&known_vector_cases,
+		&combined_mode_cases,
+		&hfn_sn_test_cases,
+		NULL /* End of suites list */
+	};
+
+	pdcp_testsuite.unit_test_suites = rte_zmalloc(NULL, sizeof(static_suites), 0);
+	if (pdcp_testsuite.unit_test_suites == NULL) {
+		RTE_LOG(ERR, USER1, "No memory for: '%s'\n", pdcp_testsuite.suite_name);
+		return TEST_FAILED;
+	}
+
+	memcpy(pdcp_testsuite.unit_test_suites, static_suites, sizeof(static_suites));
+
+	ret = unit_test_suite_runner(&pdcp_testsuite);
+	rte_free(pdcp_testsuite.unit_test_suites);
+	return ret;
 }
 
 REGISTER_TEST_COMMAND(pdcp_autotest, test_pdcp);
