diff --git a/app/test-pmd/Makefile b/app/test-pmd/Makefile
index 35ecee9..d87cae6 100644
--- a/app/test-pmd/Makefile
+++ b/app/test-pmd/Makefile
@@ -55,6 +55,7 @@ SRCS-y += macswap.c
 SRCS-y += flowgen.c
 SRCS-y += rxonly.c
 SRCS-y += txonly.c
+SRCS-y += s-txonly.c
 SRCS-y += csumonly.c
 SRCS-y += icmpecho.c
 SRCS-$(CONFIG_RTE_LIBRTE_IEEE1588) += ieee1588fwd.c
diff --git a/app/test-pmd/s-txonly.c b/app/test-pmd/s-txonly.c
new file mode 100644
index 0000000..6275136
--- /dev/null
+++ b/app/test-pmd/s-txonly.c
@@ -0,0 +1,134 @@
+/*-
+ *   BSD LICENSE
+ *
+ *   Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
+ *   All rights reserved.
+ *
+ *   Redistribution and use in source and binary forms, with or without
+ *   modification, are permitted provided that the following conditions
+ *   are met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in
+ *       the documentation and/or other materials provided with the
+ *       distribution.
+ *     * Neither the name of Intel Corporation nor the names of its
+ *       contributors may be used to endorse or promote products derived
+ *       from this software without specific prior written permission.
+ *
+ *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <stdarg.h>
+#include <string.h>
+#include <stdio.h>
+#include <errno.h>
+#include <stdint.h>
+#include <unistd.h>
+#include <inttypes.h>
+#include <assert.h>
+
+#include <rte_common.h>
+#include <rte_byteorder.h>
+#include <rte_log.h>
+#include <rte_debug.h>
+#include <rte_cycles.h>
+#include <rte_memory.h>
+#include <rte_memcpy.h>
+#include <rte_memzone.h>
+#include <rte_launch.h>
+#include <rte_eal.h>
+#include <rte_per_lcore.h>
+#include <rte_lcore.h>
+#include <rte_atomic.h>
+#include <rte_branch_prediction.h>
+#include <rte_memory.h>
+#include <rte_mempool.h>
+#include <rte_mbuf.h>
+#include <rte_memcpy.h>
+#include <rte_interrupts.h>
+#include <rte_pci.h>
+#include <rte_ether.h>
+#include <rte_ethdev.h>
+#include <rte_ip.h>
+#include <rte_tcp.h>
+#include <rte_udp.h>
+#include <rte_string_fns.h>
+#include <rte_flow.h>
+
+#include "testpmd.h"
+
+#undef MAX_PKT_BURST
+#define MAX_PKT_BURST	32
+
+/*
+ * Transmit a burst of multi-segments packets.
+ */
+static void
+pkt_burst_transmit(struct fwd_stream *fs)
+{
+	static struct rte_mbuf *pkts[MAX_PKT_BURST];
+	uint16_t nb_tx;
+	int  i;
+#ifdef RTE_TEST_PMD_RECORD_CORE_CYCLES
+	uint64_t start_tsc;
+	uint64_t end_tsc;
+	uint64_t core_cycles;
+#endif
+
+#ifdef RTE_TEST_PMD_RECORD_CORE_CYCLES
+	start_tsc = rte_rdtsc();
+#endif
+
+	for (i = 0; i < MAX_PKT_BURST; i++) {
+		if (unlikely(!pkts[i])) {
+			pkts[i] = rte_pktmbuf_alloc(current_fwd_lcore()->mbp);
+			assert(pkts[i]);
+
+			pkts[i]->data_len = tx_pkt_seg_lengths[0];
+			pkts[i]->pkt_len  = tx_pkt_seg_lengths[0];
+			pkts[i]->nb_segs  = 1;
+		}
+
+		rte_pktmbuf_refcnt_update(pkts[i], 1);
+	}
+
+	nb_tx = rte_eth_tx_burst(fs->tx_port, fs->tx_queue, pkts, MAX_PKT_BURST);
+
+	//uint32_t retry;
+	//if (unlikely(nb_tx < MAX_PKT_BURST) && fs->retry_enabled) {
+	//	retry = 0;
+	//	while (nb_tx < MAX_PKT_BURST && retry++ < burst_tx_retry_num) {
+	//		rte_delay_us(burst_tx_delay_time);
+	//		nb_tx += rte_eth_tx_burst(fs->tx_port, fs->tx_queue,
+	//				&pkts[nb_tx], MAX_PKT_BURST - nb_tx);
+	//	}
+	//}
+
+	fs->tx_packets += nb_tx;
+
+#ifdef RTE_TEST_PMD_RECORD_CORE_CYCLES
+	end_tsc = rte_rdtsc();
+	core_cycles = (end_tsc - start_tsc);
+	fs->core_cycles = (uint64_t) (fs->core_cycles + core_cycles);
+#endif
+}
+
+struct fwd_engine s_tx_only_engine = {
+	.fwd_mode_name  = "s-txonly",
+	.port_fwd_begin = NULL,
+	.port_fwd_end   = NULL,
+	.packet_fwd     = pkt_burst_transmit,
+};
diff --git a/app/test-pmd/testpmd.c b/app/test-pmd/testpmd.c
index d1041af..f224357 100644
--- a/app/test-pmd/testpmd.c
+++ b/app/test-pmd/testpmd.c
@@ -160,6 +160,7 @@ struct fwd_engine * fwd_engines[] = {
 	&flow_gen_engine,
 	&rx_only_engine,
 	&tx_only_engine,
+	&s_tx_only_engine,
 	&csum_fwd_engine,
 	&icmp_echo_engine,
 #ifdef RTE_LIBRTE_IEEE1588
diff --git a/app/test-pmd/testpmd.h b/app/test-pmd/testpmd.h
index e6c43ba..b53ce0a 100644
--- a/app/test-pmd/testpmd.h
+++ b/app/test-pmd/testpmd.h
@@ -248,6 +248,7 @@ extern struct fwd_engine mac_swap_engine;
 extern struct fwd_engine flow_gen_engine;
 extern struct fwd_engine rx_only_engine;
 extern struct fwd_engine tx_only_engine;
+extern struct fwd_engine s_tx_only_engine;
 extern struct fwd_engine csum_fwd_engine;
 extern struct fwd_engine icmp_echo_engine;
 #ifdef RTE_LIBRTE_IEEE1588
