diff --git a/trunk/3rdparty/st-srs/io.c b/trunk/3rdparty/st-srs/io.c
index 912de0b28..8b0e9294a 100644
--- a/trunk/3rdparty/st-srs/io.c
+++ b/trunk/3rdparty/st-srs/io.c
@@ -743,6 +743,36 @@ int st_sendmsg(_st_netfd_t *fd, const struct msghdr *msg, int flags, st_utime_t
 }
 
 
+int st_sendmmsg(st_netfd_t fd, struct mmsghdr *msgvec, unsigned int vlen, int flags, st_utime_t timeout)
+{
+    int n;
+    int left;
+    struct mmsghdr *p;
+
+    left = (int)vlen;
+    while (left > 0) {
+        p = msgvec + (vlen - left);
+
+        if ((n = sendmmsg(fd->osfd, p, left, flags)) < 0) {
+            if (errno == EINTR)
+                continue;
+            if (!_IO_NOT_READY_ERROR)
+                break;
+            /* Wait until the socket becomes writable */
+            if (st_netfd_poll(fd, POLLOUT, timeout) < 0)
+                break;
+        }
+
+        left -= n;
+    }
+
+    // An error is returned only if no datagrams could be sent.
+    if (left == (int)vlen) {
+        return n;
+    }
+    return (int)vlen - left;
+}
+
 
 /*
  * To open FIFOs or other special files.
diff --git a/trunk/3rdparty/st-srs/public.h b/trunk/3rdparty/st-srs/public.h
index 20b09407b..c54bd790a 100644
--- a/trunk/3rdparty/st-srs/public.h
+++ b/trunk/3rdparty/st-srs/public.h
@@ -151,6 +151,7 @@ extern int st_recvfrom(st_netfd_t fd, void *buf, int len, struct sockaddr *from,
 extern int st_sendto(st_netfd_t fd, const void *msg, int len, const struct sockaddr *to, int tolen, st_utime_t timeout);
 extern int st_recvmsg(st_netfd_t fd, struct msghdr *msg, int flags, st_utime_t timeout);
 extern int st_sendmsg(st_netfd_t fd, const struct msghdr *msg, int flags, st_utime_t timeout);
+extern int st_sendmmsg(st_netfd_t fd, struct mmsghdr *msgvec, unsigned int vlen, int flags, st_utime_t timeout);
 extern st_netfd_t st_open(const char *path, int oflags, mode_t mode);
 
 #ifdef DEBUG
diff --git a/trunk/src/app/srs_app_listener.cpp b/trunk/src/app/srs_app_listener.cpp
index fa02a3c4e..4a23ed399 100755
--- a/trunk/src/app/srs_app_listener.cpp
+++ b/trunk/src/app/srs_app_listener.cpp
@@ -316,6 +316,21 @@ srs_error_t SrsUdpMuxSocket::sendto(void* data, int size, srs_utime_t timeout)
     return err;
 }
 
+srs_netfd_t SrsUdpMuxSocket::stfd()
+{
+    return lfd;
+}
+
+sockaddr_in* SrsUdpMuxSocket::peer_addr()
+{
+    return (sockaddr_in*)&from;
+}
+
+socklen_t SrsUdpMuxSocket::peer_addrlen()
+{
+    return (socklen_t)fromlen;
+}
+
 std::string SrsUdpMuxSocket::get_peer_id()
 {
     char id_buf[1024];
diff --git a/trunk/src/app/srs_app_listener.hpp b/trunk/src/app/srs_app_listener.hpp
index dce082efd..0222413c1 100644
--- a/trunk/src/app/srs_app_listener.hpp
+++ b/trunk/src/app/srs_app_listener.hpp
@@ -27,6 +27,7 @@
 #include <srs_core.hpp>
 
 #include <sys/socket.h>
+#include <netinet/in.h>
 
 #include <string>
 
@@ -148,6 +149,10 @@ public:
     int recvfrom(srs_utime_t timeout);
     srs_error_t sendto(void* data, int size, srs_utime_t timeout);
 
+    srs_netfd_t stfd();
+    sockaddr_in* peer_addr();
+    socklen_t peer_addrlen();
+
     char* data() { return buf; }
     int size() { return nread; }
     std::string get_peer_ip() const { return peer_ip; }
diff --git a/trunk/src/app/srs_app_rtc_conn.cpp b/trunk/src/app/srs_app_rtc_conn.cpp
index 6b464f173..e8963a213 100644
--- a/trunk/src/app/srs_app_rtc_conn.cpp
+++ b/trunk/src/app/srs_app_rtc_conn.cpp
@@ -564,6 +564,7 @@ void SrsRtcSenderThread::send_and_free_messages(SrsSharedPtrMessage** msgs, int
 {
     srs_error_t err = srs_success;
 
+    vector<mmsghdr> mhdrs;
 	for (int i = 0; i < nb_msgs; i++) {
         SrsSharedPtrMessage* msg = msgs[i];
 
@@ -585,22 +586,42 @@ void SrsRtcSenderThread::send_and_free_messages(SrsSharedPtrMessage** msgs, int
             }
 
             int length = pkt->size;
-            char buf[kRtpPacketSize];
+            char* buf = new char[kRtpPacketSize];
             if ((err = rtc_session->dtls_session->protect_rtp(buf, pkt->payload, length)) != srs_success) {
-                srs_warn("srtp err %s", srs_error_desc(err).c_str());
-                srs_freep(err);
+                srs_warn("srtp err %s", srs_error_desc(err).c_str()); srs_freep(err); srs_freepa(buf);
                 continue;
             }
 
-            // TODO: use sendmmsg to send multi packet one system call
-            if ((err = udp_mux_skt->sendto(buf, length, 0)) != srs_success) {
-                srs_warn("send err %s", srs_error_desc(err).c_str());
-                srs_freep(err);
-            }
+            mmsghdr mhdr;
+            memset(&mhdr, 0, sizeof(mmsghdr));
+            mhdr.msg_hdr.msg_name = (sockaddr_in*)udp_mux_skt->peer_addr();
+            mhdr.msg_hdr.msg_namelen = udp_mux_skt->peer_addrlen();
+            mhdr.msg_hdr.msg_iovlen = 1;
+            mhdr.msg_hdr.msg_iov = new iovec();
+            mhdr.msg_hdr.msg_iov->iov_base = buf;
+            mhdr.msg_hdr.msg_iov->iov_len = length;
+            mhdrs.push_back(mhdr);
         }
 
         srs_freep(msg);
     }
+
+
+    if (!mhdrs.empty()) {
+        mmsghdr* msgvec = &mhdrs[0];
+        unsigned int vlen = (unsigned int)mhdrs.size();
+        int r0 = srs_sendmmsg(udp_mux_skt->stfd(), msgvec, vlen, 0, SRS_UTIME_NO_TIMEOUT);
+        if (r0 != (int)vlen) {
+            srs_warn("sendmsg %d msgs, %d done", vlen, r0);
+        }
+    }
+    for (int i = 0; i < (int)mhdrs.size(); i++) {
+        msghdr* hdr = &mhdrs[i].msg_hdr;
+        for (int i = 0; i < (int)hdr->msg_iovlen; i++) {
+            iovec* iov = hdr->msg_iov + i;
+            delete (char*)iov->iov_base;
+        }
+    }
 }
 
 SrsRtcSession::SrsRtcSession(SrsRtcServer* rtc_svr, const SrsRequest& req, const std::string& un, int context_id)
diff --git a/trunk/src/core/srs_core_performance.hpp b/trunk/src/core/srs_core_performance.hpp
index e265c373b..122a1469f 100644
--- a/trunk/src/core/srs_core_performance.hpp
+++ b/trunk/src/core/srs_core_performance.hpp
@@ -124,7 +124,7 @@
 #define SRS_PERF_QUEUE_COND_WAIT
 #ifdef SRS_PERF_QUEUE_COND_WAIT
     #define SRS_PERF_MW_MIN_MSGS 8
-    #define SRS_PERF_MW_MIN_MSGS_FOR_RTC 0
+    #define SRS_PERF_MW_MIN_MSGS_FOR_RTC 4
 #endif
 /**
  * the default value of vhost for
diff --git a/trunk/src/service/srs_service_st.cpp b/trunk/src/service/srs_service_st.cpp
index 947150f61..8ed113be2 100644
--- a/trunk/src/service/srs_service_st.cpp
+++ b/trunk/src/service/srs_service_st.cpp
@@ -407,6 +407,31 @@ int srs_sendmsg(srs_netfd_t stfd, const struct msghdr *msg, int flags, srs_utime
     return st_sendmsg((st_netfd_t)stfd, msg, flags, (st_utime_t)timeout);
 }
 
+int srs_sendmmsg(srs_netfd_t stfd, struct mmsghdr *msgvec, unsigned int vlen, int flags, srs_utime_t timeout)
+{
+#if defined(SRS_AUTO_OSX)
+    // @see http://man7.org/linux/man-pages/man2/sendmmsg.2.html
+    for (int i = 0; i < (int)vlen; ++i) {
+        struct mmsghdr* p = msgvec + i;
+        int n = srs_sendmsg(stfd, &p->msg_hdr, flags, timeout);
+        if (n < 0) {
+            // An error is returned only if no datagrams could be sent.
+            if (i == 0) {
+                return n;
+            }
+            return i + 1;
+        }
+
+        p->msg_len = n;
+    }
+    // Returns the number of messages sent from msgvec; if this is less than vlen, the caller can retry with a
+    // further sendmmsg() call to send the remaining messages.
+    return vlen;
+#else
+    return st_sendmmsg((st_netfd_t)stfd, msgvec, vlen, flags, (st_utime_t)timeout);
+#endif
+}
+
 srs_netfd_t srs_accept(srs_netfd_t stfd, struct sockaddr *addr, int *addrlen, srs_utime_t timeout)
 {
     return (srs_netfd_t)st_accept((st_netfd_t)stfd, addr, addrlen, (st_utime_t)timeout);
diff --git a/trunk/src/service/srs_service_st.hpp b/trunk/src/service/srs_service_st.hpp
index 947950e85..ed10fd667 100644
--- a/trunk/src/service/srs_service_st.hpp
+++ b/trunk/src/service/srs_service_st.hpp
@@ -90,6 +90,7 @@ extern srs_netfd_t srs_netfd_open(int osfd);
 extern int srs_recvfrom(srs_netfd_t stfd, void *buf, int len, struct sockaddr *from, int *fromlen, srs_utime_t timeout);
 extern int srs_sendto(srs_netfd_t stfd, void *buf, int len, const struct sockaddr *to, int tolen, srs_utime_t timeout);
 extern int srs_sendmsg(srs_netfd_t stfd, const struct msghdr *msg, int flags, srs_utime_t timeout);
+extern int srs_sendmmsg(srs_netfd_t stfd, struct mmsghdr *msgvec, unsigned int vlen, int flags, srs_utime_t timeout);
 
 extern srs_netfd_t srs_accept(srs_netfd_t stfd, struct sockaddr *addr, int *addrlen, srs_utime_t timeout);