diff --git a/samples/bluetooth/central_gatt_write/src/gatt_write_common.c b/samples/bluetooth/central_gatt_write/src/gatt_write_common.c
index 99d2e830aea90..3dfed916f913a 100644
--- a/samples/bluetooth/central_gatt_write/src/gatt_write_common.c
+++ b/samples/bluetooth/central_gatt_write/src/gatt_write_common.c
@@ -17,6 +17,10 @@
 static uint32_t phy_update_countdown;
 static uint8_t phy_param_idx;
 
+/* Count down number of metrics intervals before performing a param update */
+#define PARAM_UPDATE_COUNTDOWN PHY_UPDATE_COUNTDOWN
+static uint32_t param_update_countdown;
+
 static void phy_update_iterate(struct bt_conn *conn)
 {
 	const struct bt_conn_le_phy_param phy_param[] = {
@@ -178,6 +182,34 @@ static void write_cmd_cb(struct bt_conn *conn, void *user_data)
 			phy_update_iterate(conn);
 		}
 
+		const struct bt_le_conn_param update_params[2] = {{
+				.interval_min = 0x0029,
+				.interval_max = 0x0029,
+				.latency = 0,
+				.timeout = 31,
+			}, {
+				.interval_min = 0x0028,
+				.interval_max = 0x0028,
+				.latency = 0,
+				.timeout = 30,
+			},
+		};
+		static uint8_t param_update_count;
+		int err;
+
+		if ((param_update_countdown--) != 0U) {
+			return;
+		}
+
+		param_update_countdown = PARAM_UPDATE_COUNTDOWN;
+
+		err = bt_conn_le_param_update(conn, &update_params[param_update_count & 0x1]);
+		if (err != 0) {
+			printk("Parameter update failed (err %d)\n", err);
+		}
+
+		param_update_count++;
+
 	} else {
 		uint16_t len;
 
@@ -256,6 +288,14 @@ static void connected(struct bt_conn *conn, uint8_t conn_err)
 		phy_update_countdown = PHY_UPDATE_COUNTDOWN;
 		phy_param_idx = 0U;
 	}
+
+	/* Every 1 second the acknowledged total GATT Write without Response data size is used for
+	 * the throughput calculation.
+	 * PHY update is performed in reference to this calculation interval, and connection update
+	 * is offset by 1 of this interval so that connection update is initiated one such interval
+	 * after PHY update was requested.
+	 */
+	param_update_countdown = PARAM_UPDATE_COUNTDOWN + 1U;
 }
 
 static void disconnected(struct bt_conn *conn, uint8_t reason)
diff --git a/subsys/bluetooth/controller/ll_sw/ull_conn.c b/subsys/bluetooth/controller/ll_sw/ull_conn.c
index fa4eb269e7b20..a9c1668afe665 100644
--- a/subsys/bluetooth/controller/ll_sw/ull_conn.c
+++ b/subsys/bluetooth/controller/ll_sw/ull_conn.c
@@ -127,23 +127,18 @@ static uint8_t force_md_cnt_calc(struct lll_conn *lll_conn, uint32_t tx_rate);
 				(LL_LENGTH_OCTETS_TX_MAX + \
 				BT_CTLR_USER_TX_BUFFER_OVERHEAD))
 
-#define CONN_DATA_BUFFERS CONFIG_BT_BUF_ACL_TX_COUNT
-
-static MFIFO_DEFINE(conn_tx, sizeof(struct lll_tx), CONN_DATA_BUFFERS);
+static MFIFO_DEFINE(conn_tx, sizeof(struct lll_tx), CONFIG_BT_BUF_ACL_TX_COUNT);
 static MFIFO_DEFINE(conn_ack, sizeof(struct lll_tx),
-		    (CONN_DATA_BUFFERS +
-		     LLCP_TX_CTRL_BUF_COUNT));
+		    (CONFIG_BT_BUF_ACL_TX_COUNT + LLCP_TX_CTRL_BUF_COUNT));
 
 static struct {
 	void *free;
-	uint8_t pool[CONN_TX_BUF_SIZE * CONN_DATA_BUFFERS];
+	uint8_t pool[CONN_TX_BUF_SIZE * CONFIG_BT_BUF_ACL_TX_COUNT];
 } mem_conn_tx;
 
 static struct {
 	void *free;
-	uint8_t pool[sizeof(memq_link_t) *
-		     (CONN_DATA_BUFFERS +
-		      LLCP_TX_CTRL_BUF_COUNT)];
+	uint8_t pool[sizeof(memq_link_t) * (CONFIG_BT_BUF_ACL_TX_COUNT + LLCP_TX_CTRL_BUF_COUNT)];
 } mem_link_tx;
 
 #if defined(CONFIG_BT_CTLR_DATA_LENGTH)
@@ -1483,6 +1478,21 @@ void ull_conn_tx_lll_enqueue(struct ll_conn *conn, uint8_t count)
 	}
 }
 
+uint16_t ull_conn_tx_enqueue_count_get(struct ll_conn *conn)
+{
+	uint16_t count = 0;
+	memq_link_t *curr;
+
+	curr = memq_peek(conn->lll.memq_tx.head, conn->lll.memq_tx.tail, NULL);
+	while (curr != NULL) {
+		count++;
+
+		curr = memq_peek(curr->next, conn->lll.memq_tx.tail, NULL);
+	}
+
+	return count;
+}
+
 void ull_conn_link_tx_release(void *link)
 {
 	mem_release(link, &mem_link_tx.free);
@@ -1693,14 +1703,11 @@ static int init_reset(void)
 	}
 
 	/* Initialize tx pool. */
-	mem_init(mem_conn_tx.pool, CONN_TX_BUF_SIZE, CONN_DATA_BUFFERS,
-		 &mem_conn_tx.free);
+	mem_init(mem_conn_tx.pool, CONN_TX_BUF_SIZE, CONFIG_BT_BUF_ACL_TX_COUNT, &mem_conn_tx.free);
 
 	/* Initialize tx link pool. */
 	mem_init(mem_link_tx.pool, sizeof(memq_link_t),
-		 (CONN_DATA_BUFFERS +
-		  LLCP_TX_CTRL_BUF_COUNT),
-		 &mem_link_tx.free);
+		 (CONFIG_BT_BUF_ACL_TX_COUNT + LLCP_TX_CTRL_BUF_COUNT), &mem_link_tx.free);
 
 	/* Initialize control procedure system. */
 	ull_cp_init();
diff --git a/subsys/bluetooth/controller/ll_sw/ull_conn_internal.h b/subsys/bluetooth/controller/ll_sw/ull_conn_internal.h
index dad6d5e29e0e1..0b03369b55587 100644
--- a/subsys/bluetooth/controller/ll_sw/ull_conn_internal.h
+++ b/subsys/bluetooth/controller/ll_sw/ull_conn_internal.h
@@ -31,6 +31,7 @@ int ull_conn_llcp(struct ll_conn *conn, uint32_t ticks_at_expire,
 void ull_conn_done(struct node_rx_event_done *done);
 void ull_conn_tx_demux(uint8_t count);
 void ull_conn_tx_lll_enqueue(struct ll_conn *conn, uint8_t count);
+uint16_t ull_conn_tx_enqueue_count_get(struct ll_conn *conn);
 void ull_conn_link_tx_release(void *link);
 uint8_t ull_conn_ack_last_idx_get(void);
 memq_link_t *ull_conn_ack_peek(uint8_t *ack_last, uint16_t *handle,
diff --git a/subsys/bluetooth/controller/ll_sw/ull_llcp_conn_upd.c b/subsys/bluetooth/controller/ll_sw/ull_llcp_conn_upd.c
index b107371dc77ff..b16d72a74b7f9 100644
--- a/subsys/bluetooth/controller/ll_sw/ull_llcp_conn_upd.c
+++ b/subsys/bluetooth/controller/ll_sw/ull_llcp_conn_upd.c
@@ -438,7 +438,9 @@ static void lp_cu_send_conn_update_ind_finalize(struct ll_conn *conn, struct pro
 static void lp_cu_send_conn_update_ind(struct ll_conn *conn, struct proc_ctx *ctx, uint8_t evt,
 				       void *param)
 {
-	if (llcp_lr_ispaused(conn) || !llcp_tx_alloc_peek(conn, ctx)) {
+	if (llcp_lr_ispaused(conn) || !llcp_tx_alloc_peek(conn, ctx) ||
+	    ull_conn_tx_enqueue_count_get(conn) != 0U) {
+		llcp_tx_pause_data(conn, LLCP_TX_QUEUE_PAUSE_DATA_CONN_UPD);
 		ctx->state = LP_CU_STATE_WAIT_TX_CONN_UPDATE_IND;
 	} else {
 		/* ensure alloc of TX node, before possibly waiting for NTF node */
@@ -448,6 +450,7 @@ static void lp_cu_send_conn_update_ind(struct ll_conn *conn, struct proc_ctx *ct
 			ctx->state = LP_CU_STATE_WAIT_NTF_AVAIL;
 		} else {
 			lp_cu_send_conn_update_ind_finalize(conn, ctx, evt, param);
+			llcp_tx_resume_data(conn, LLCP_TX_QUEUE_PAUSE_DATA_CONN_UPD);
 		}
 	}
 }
@@ -459,6 +462,7 @@ static void lp_cu_st_wait_ntf_avail(struct ll_conn *conn, struct proc_ctx *ctx,
 	case LP_CU_EVT_RUN:
 		if (llcp_ntf_alloc_is_available()) {
 			lp_cu_send_conn_update_ind_finalize(conn, ctx, evt, param);
+			llcp_tx_resume_data(conn, LLCP_TX_QUEUE_PAUSE_DATA_CONN_UPD);
 		}
 		break;
 	default:
diff --git a/subsys/bluetooth/controller/ll_sw/ull_llcp_internal.h b/subsys/bluetooth/controller/ll_sw/ull_llcp_internal.h
index 446d78aeadb73..8c50558a08e1f 100644
--- a/subsys/bluetooth/controller/ll_sw/ull_llcp_internal.h
+++ b/subsys/bluetooth/controller/ll_sw/ull_llcp_internal.h
@@ -47,6 +47,7 @@ enum llcp_tx_q_pause_data_mask {
 	LLCP_TX_QUEUE_PAUSE_DATA_PHY_UPDATE = 0x02,
 	LLCP_TX_QUEUE_PAUSE_DATA_DATA_LENGTH = 0x04,
 	LLCP_TX_QUEUE_PAUSE_DATA_TERMINATE = 0x08,
+	LLCP_TX_QUEUE_PAUSE_DATA_CONN_UPD = 0x10,
 };
 
 #if ((CONFIG_BT_CTLR_LLCP_COMMON_TX_CTRL_BUF_NUM <\
diff --git a/tests/bsim/bluetooth/ll/throughput/prj.conf b/tests/bsim/bluetooth/ll/throughput/prj.conf
index e8848bbf25dbd..2306711e7141a 100644
--- a/tests/bsim/bluetooth/ll/throughput/prj.conf
+++ b/tests/bsim/bluetooth/ll/throughput/prj.conf
@@ -24,7 +24,7 @@ CONFIG_BT_BUF_CMD_TX_SIZE=255
 
 # BT HCI Event Buffers
 # Greater than BT_BUF_ACL_TX_COUNT, to be able to receive Number of Completed Packets events
-CONFIG_BT_BUF_EVT_RX_COUNT=4
+CONFIG_BT_BUF_EVT_RX_COUNT=7
 CONFIG_BT_BUF_EVT_RX_SIZE=255
 
 # BT HCI Discardable Event Buffers
@@ -32,7 +32,7 @@ CONFIG_BT_BUF_EVT_DISCARDABLE_COUNT=3
 CONFIG_BT_BUF_EVT_DISCARDABLE_SIZE=255
 
 # BT HCI ACL TX Data Buffers
-CONFIG_BT_BUF_ACL_TX_COUNT=3
+CONFIG_BT_BUF_ACL_TX_COUNT=6
 CONFIG_BT_BUF_ACL_TX_SIZE=251
 
 # BT HCI ACL RX Data Buffers