diff --git a/daemon/face/unicast-udp-transport.cpp b/daemon/face/unicast-udp-transport.cpp
new file mode 100644
index 0000000..eb8ab66
--- /dev/null
+++ b/daemon/face/unicast-udp-transport.cpp
@@ -0,0 +1,102 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+ * Copyright (c) 2014-2015,  Regents of the University of California,
+ *                           Arizona Board of Regents,
+ *                           Colorado State University,
+ *                           University Pierre & Marie Curie, Sorbonne University,
+ *                           Washington University in St. Louis,
+ *                           Beijing Institute of Technology,
+ *                           The University of Memphis.
+ *
+ * This file is part of NFD (Named Data Networking Forwarding Daemon).
+ * See AUTHORS.md for complete list of NFD authors and contributors.
+ *
+ * NFD is free software: you can redistribute it and/or modify it under the terms
+ * of the GNU General Public License as published by the Free Software Foundation,
+ * either version 3 of the License, or (at your option) any later version.
+ *
+ * NFD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
+ * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
+ * PURPOSE.  See the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * NFD, e.g., in COPYING.md file.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "unicast-udp-transport.hpp"
+
+#ifdef __linux__
+#include <cerrno>       // for errno
+#include <cstring>      // for std::strerror()
+#include <netinet/in.h> // for IP_MTU_DISCOVER and IP_PMTUDISC_DONT
+#include <sys/socket.h> // for setsockopt()
+#endif
+
+namespace nfd {
+namespace face {
+
+NFD_LOG_INCLASS_TEMPLATE_SPECIALIZATION_DEFINE(DatagramTransport, UnicastUdpTransport::protocol,
+                                               "UnicastUdpTransport");
+
+UnicastUdpTransport::UnicastUdpTransport(protocol::socket&& socket,
+                                         ndn::nfd::FacePersistency persistency,
+                                         const time::seconds& idleTimeout)
+  : DatagramTransport(std::move(socket))
+  , m_idleTimeout(idleTimeout)
+  , m_lastIdleCheck(time::steady_clock::now())
+{
+  this->setLocalUri(FaceUri(m_socket.local_endpoint()));
+  this->setRemoteUri(FaceUri(m_socket.remote_endpoint()));
+  this->setPersistency(persistency);
+  this->setLinkType(ndn::nfd::LINK_TYPE_POINT_TO_POINT);
+
+  NFD_LOG_FACE_INFO("Creating transport");
+
+#ifdef __linux__
+  //
+  // By default, Linux does path MTU discovery on IPv4 sockets,
+  // and sets the DF (Don't Fragment) flag on datagrams smaller
+  // than the interface MTU. However this does not work for us,
+  // because we cannot properly respond to ICMP "packet too big"
+  // messages by fragmenting the packet at the application level,
+  // since we want to rely on IP for fragmentation and reassembly.
+  //
+  // Therefore, we disable PMTU discovery, which prevents the kernel
+  // from setting the DF flag on outgoing datagrams, and thus allows
+  // routers along the path to perform fragmentation as needed.
+  //
+  const int value = IP_PMTUDISC_DONT;
+  if (::setsockopt(m_socket.native_handle(), IPPROTO_IP,
+                   IP_MTU_DISCOVER, &value, sizeof(value)) < 0) {
+    NFD_LOG_FACE_WARN("Failed to disable path MTU discovery: " << std::strerror(errno));
+  }
+#endif
+
+  if (getPersistency() == ndn::nfd::FACE_PERSISTENCY_ON_DEMAND &&
+      m_idleTimeout > time::seconds::zero()) {
+    m_closeIfIdleEvent = scheduler::schedule(m_idleTimeout, bind(&UnicastUdpTransport::closeIfIdle, this));
+  }
+}
+
+void
+UnicastUdpTransport::closeIfIdle()
+{
+  // transport can be switched from on-demand to non-on-demand mode
+  // (non-on-demand -> on-demand transition is not allowed)
+  if (getPersistency() == ndn::nfd::FACE_PERSISTENCY_ON_DEMAND) {
+    if (!hasBeenUsedRecently()) {
+      NFD_LOG_FACE_INFO("Closing due to inactivity");
+      this->close();
+    }
+    else {
+      resetRecentUsage();
+
+      m_lastIdleCheck = time::steady_clock::now();
+      m_closeIfIdleEvent = scheduler::schedule(m_idleTimeout, bind(&UnicastUdpTransport::closeIfIdle, this));
+    }
+  }
+  // else do nothing and do not reschedule the event
+}
+
+} // namespace face
+} // namespace nfd