diff --git a/daemon/face/generic-link-service.cpp b/daemon/face/generic-link-service.cpp
index 23e2ce2..d6d6c02 100644
--- a/daemon/face/generic-link-service.cpp
+++ b/daemon/face/generic-link-service.cpp
@@ -30,14 +30,26 @@
 
 NFD_LOG_INIT("GenericLinkService");
 
+GenericLinkServiceCounters::GenericLinkServiceCounters(const LpReassembler& reassembler)
+  : nReassembling(reassembler)
+{
+}
+
 GenericLinkService::Options::Options()
   : allowLocalFields(false)
+  , allowFragmentation(false)
+  , allowReassembly(false)
 {
 }
 
 GenericLinkService::GenericLinkService(const GenericLinkService::Options& options)
-  : m_options(options)
+  : GenericLinkServiceCounters(m_reassembler)
+  , m_options(options)
+  , m_fragmenter(m_options.fragmenterOptions, this)
+  , m_reassembler(m_options.reassemblerOptions, this)
+  , m_lastSeqNo(-2)
 {
+  m_reassembler.beforeTimeout.connect(bind([this] { ++nReassemblyTimeouts; }));
 }
 
 void
@@ -47,9 +59,8 @@
   if (m_options.allowLocalFields) {
     encodeLocalFields(interest, lpPacket);
   }
-  Transport::Packet packet;
-  packet.packet = lpPacket.wireEncode();
-  sendPacket(std::move(packet));
+
+  sendNetPacket(std::move(lpPacket));
 }
 
 void
@@ -59,9 +70,8 @@
   if (m_options.allowLocalFields) {
     encodeLocalFields(data, lpPacket);
   }
-  Transport::Packet packet;
-  packet.packet = lpPacket.wireEncode();
-  sendPacket(std::move(packet));
+
+  sendNetPacket(std::move(lpPacket));
 }
 
 void
@@ -72,9 +82,8 @@
   if (m_options.allowLocalFields) {
     encodeLocalFields(nack.getInterest(), lpPacket);
   }
-  Transport::Packet packet;
-  packet.packet = lpPacket.wireEncode();
-  sendPacket(std::move(packet));
+
+  sendNetPacket(std::move(lpPacket));
 }
 
 bool
@@ -117,6 +126,59 @@
 }
 
 void
+GenericLinkService::sendNetPacket(lp::Packet&& pkt)
+{
+  std::vector<lp::Packet> frags;
+  const ssize_t mtu = this->getTransport()->getMtu();
+  if (m_options.allowFragmentation && mtu != MTU_UNLIMITED) {
+    bool isOk = false;
+    std::tie(isOk, frags) = m_fragmenter.fragmentPacket(pkt, mtu);
+    if (!isOk) {
+      // fragmentation failed (warning is logged by LpFragmenter)
+      ++nFragmentationErrors;
+      return;
+    }
+  }
+  else {
+    frags.push_back(pkt);
+  }
+
+  if (frags.size() > 1) {
+    // sequence is needed only if packet is fragmented
+    assignSequences(frags);
+  }
+  else {
+    // even if indexed fragmentation is enabled, the fragmenter should not
+    // fragment the packet if it can fit in MTU
+    BOOST_ASSERT(frags.size() > 0);
+    BOOST_ASSERT(!frags.front().has<lp::FragIndexField>());
+    BOOST_ASSERT(!frags.front().has<lp::FragCountField>());
+  }
+
+  for (const lp::Packet& frag : frags) {
+    Transport::Packet tp(frag.wireEncode());
+    if (mtu != MTU_UNLIMITED && tp.packet.size() > static_cast<size_t>(mtu)) {
+      ++nOutOverMtu;
+      NFD_LOG_FACE_WARN("attempt to send packet over MTU limit");
+      continue;
+    }
+    sendPacket(std::move(tp));
+  }
+}
+
+void
+GenericLinkService::assignSequence(lp::Packet& pkt)
+{
+  pkt.set<lp::SequenceField>(++m_lastSeqNo);
+}
+
+void
+GenericLinkService::assignSequences(std::vector<lp::Packet>& pkts)
+{
+  std::for_each(pkts.begin(), pkts.end(), bind(&GenericLinkService::assignSequence, this, _1));
+}
+
+void
 GenericLinkService::doReceivePacket(Transport::Packet&& packet)
 {
   try {
@@ -127,38 +189,55 @@
       return;
     }
 
-    if (pkt.has<lp::FragIndexField>() || pkt.has<lp::FragCountField>()) {
-      NFD_LOG_FACE_WARN("received fragment, but reassembly not implemented: DROP");
+    if ((pkt.has<lp::FragIndexField>() || pkt.has<lp::FragCountField>()) &&
+        !m_options.allowReassembly) {
+      NFD_LOG_FACE_WARN("received fragment, but reassembly disabled: DROP");
       return;
     }
 
-    ndn::Buffer::const_iterator fragBegin, fragEnd;
-    std::tie(fragBegin, fragEnd) = pkt.get<lp::FragmentField>();
-    Block netPkt(&*fragBegin, std::distance(fragBegin, fragEnd));
+    bool isReassembled = false;
+    Block netPkt;
+    lp::Packet firstPkt;
+    std::tie(isReassembled, netPkt, firstPkt) = m_reassembler.receiveFragment(packet.remoteEndpoint,
+                                                                              pkt);
+    if (isReassembled) {
+      this->decodeNetPacket(netPkt, firstPkt);
+    }
+  }
+  catch (const tlv::Error& e) {
+    ++this->nInLpInvalid;
+    NFD_LOG_FACE_WARN("packet parse error (" << e.what() << "): DROP");
+  }
+}
 
+void
+GenericLinkService::decodeNetPacket(const Block& netPkt, const lp::Packet& firstPkt)
+{
+  try {
     switch (netPkt.type()) {
       case tlv::Interest:
-        if (pkt.has<lp::NackField>()) {
-          this->decodeNack(netPkt, pkt);
+        if (firstPkt.has<lp::NackField>()) {
+          this->decodeNack(netPkt, firstPkt);
         }
         else {
-          this->decodeInterest(netPkt, pkt);
+          this->decodeInterest(netPkt, firstPkt);
         }
         break;
       case tlv::Data:
-        this->decodeData(netPkt, pkt);
+        this->decodeData(netPkt, firstPkt);
         break;
       default:
+        ++this->nInNetInvalid;
         NFD_LOG_FACE_WARN("unrecognized network-layer packet TLV-TYPE " << netPkt.type() << ": DROP");
         return;
     }
   }
   catch (const tlv::Error& e) {
+    ++this->nInNetInvalid;
     NFD_LOG_FACE_WARN("packet parse error (" << e.what() << "): DROP");
   }
 }
 
-
 void
 GenericLinkService::decodeInterest(const Block& netPkt, const lp::Packet& firstPkt)
 {
@@ -179,6 +258,7 @@
   }
 
   if (firstPkt.has<lp::CachePolicyField>()) {
+    ++this->nInNetInvalid;
     NFD_LOG_FACE_WARN("received CachePolicy with Interest: DROP");
     return;
   }
@@ -199,11 +279,13 @@
   auto data = make_shared<Data>(netPkt);
 
   if (firstPkt.has<lp::NackField>()) {
+    ++this->nInNetInvalid;
     NFD_LOG_FACE_WARN("received Nack with Data: DROP");
     return;
   }
 
   if (firstPkt.has<lp::NextHopFaceIdField>()) {
+    ++this->nInNetInvalid;
     NFD_LOG_FACE_WARN("received NextHopFaceId with Data: DROP");
     return;
   }
@@ -216,6 +298,7 @@
           data->setCachingPolicy(ndn::nfd::LocalControlHeader::CachingPolicy::NO_CACHE);
           break;
         default:
+          ++this->nInNetInvalid;
           NFD_LOG_FACE_WARN("unrecognized CachePolicyType " << policy << ": DROP");
           return;
       }
@@ -242,11 +325,13 @@
   nack.setHeader(firstPkt.get<lp::NackField>());
 
   if (firstPkt.has<lp::NextHopFaceIdField>()) {
+    ++this->nInNetInvalid;
     NFD_LOG_FACE_WARN("received NextHopFaceId with Nack: DROP");
     return;
   }
 
   if (firstPkt.has<lp::CachePolicyField>()) {
+    ++this->nInNetInvalid;
     NFD_LOG_FACE_WARN("received CachePolicy with Nack: DROP");
     return;
   }
diff --git a/daemon/face/generic-link-service.hpp b/daemon/face/generic-link-service.hpp
index ae3328f..d7cc22f 100644
--- a/daemon/face/generic-link-service.hpp
+++ b/daemon/face/generic-link-service.hpp
@@ -30,16 +30,54 @@
 #include "core/logger.hpp"
 
 #include "link-service.hpp"
-
-#include <ndn-cxx/lp/packet.hpp>
+#include "lp-fragmenter.hpp"
+#include "lp-reassembler.hpp"
 
 namespace nfd {
 namespace face {
 
+/** \brief counters provided by GenericLinkService
+ *  \note The type name 'GenericLinkServiceCounters' is implementation detail.
+ *        Use 'GenericLinkService::Counters' in public API.
+ */
+class GenericLinkServiceCounters : public virtual LinkService::Counters
+{
+public:
+  explicit
+  GenericLinkServiceCounters(const LpReassembler& reassembler);
+
+  /** \brief count of failed fragmentations
+   */
+  PacketCounter nFragmentationErrors;
+
+  /** \brief count of outgoing LpPackets dropped due to exceeding MTU limit
+   *
+   *  If this counter is non-zero, the operator should enable fragmentation.
+   */
+  PacketCounter nOutOverMtu;
+
+  /** \brief count of invalid LpPackets dropped before reassembly
+   */
+  PacketCounter nInLpInvalid;
+
+  /** \brief count of network-layer packets currently being reassembled
+   */
+  SizeCounter<LpReassembler> nReassembling;
+
+  /** \brief count of dropped partial network-layer packets due to reassembly timeout
+   */
+  PacketCounter nReassemblyTimeouts;
+
+  /** \brief count of invalid reassembled network-layer packets dropped
+   */
+  PacketCounter nInNetInvalid;
+};
+
 /** \brief GenericLinkService is a LinkService that implements the NDNLPv2 protocol
  *  \sa http://redmine.named-data.net/projects/nfd/wiki/NDNLPv2
  */
 class GenericLinkService : public LinkService
+                         , protected virtual GenericLinkServiceCounters
 {
 public:
   /** \brief Options that control the behavior of GenericLinkService
@@ -50,13 +88,31 @@
     Options();
 
   public:
-    // TODO #3171: fragmentation and reassembly options
-
     /** \brief enables encoding of IncomingFaceId, and decoding of NextHopFaceId and CachePolicy
      */
     bool allowLocalFields;
+
+    /** \brief enables fragmentation
+     */
+    bool allowFragmentation;
+
+    /** \brief options for fragmentation
+     */
+    LpFragmenter::Options fragmenterOptions;
+
+    /** \brief enables reassembly
+     */
+    bool allowReassembly;
+
+    /** \brief options for reassembly
+     */
+    LpReassembler::Options reassemblerOptions;
   };
 
+  /** \brief counters provided by GenericLinkService
+   */
+  typedef GenericLinkServiceCounters Counters;
+
   explicit
   GenericLinkService(const Options& options = Options());
 
@@ -70,7 +126,10 @@
   void
   setOptions(const Options& options);
 
-private: // send path entrypoint
+  virtual const Counters&
+  getCounters() const DECL_OVERRIDE;
+
+private: // send path
   /** \brief sends Interest
    */
   void
@@ -87,13 +146,6 @@
   void
   doSendNack(const ndn::lp::Nack& nack) DECL_OVERRIDE;
 
-private: // receive path entrypoint
-  /** \brief receives Packet
-   */
-  void
-  doReceivePacket(Transport::Packet&& packet) DECL_OVERRIDE;
-
-private: // encoding and decoding
   /** \brief encode IncomingFaceId into LpPacket and verify local fields
    */
   static bool
@@ -104,6 +156,38 @@
   static bool
   encodeLocalFields(const Data& data, lp::Packet& lpPacket);
 
+  /** \brief encode and send a complete network layer packet
+   *  \param pkt LpPacket containing a complete network layer packet
+   */
+  void
+  sendNetPacket(lp::Packet&& pkt);
+
+  /** \brief assign a sequence number to an LpPacket
+   */
+  void
+  assignSequence(lp::Packet& pkt);
+
+  /** \brief assign consecutive sequence numbers to LpPackets
+   */
+  void
+  assignSequences(std::vector<lp::Packet>& pkts);
+
+private: // receive path
+  /** \brief receive Packet from Transport
+   */
+  void
+  doReceivePacket(Transport::Packet&& packet) DECL_OVERRIDE;
+
+  /** \brief decode incoming network-layer packet
+   *  \param netPkt reassembled network-layer packet
+   *  \param firstPkt LpPacket of first fragment
+   *
+   *  If decoding is successful, a receive signal is emitted;
+   *  otherwise, a warning is logged.
+   */
+  void
+  decodeNetPacket(const Block& netPkt, const lp::Packet& firstPkt);
+
   /** \brief decode incoming Interest
    *  \param netPkt reassembled network-layer packet; TLV-TYPE must be Interest
    *  \param firstPkt LpPacket of first fragment; must not have Nack field
@@ -142,6 +226,9 @@
 
 private:
   Options m_options;
+  LpFragmenter m_fragmenter;
+  LpReassembler m_reassembler;
+  lp::Sequence m_lastSeqNo;
 };
 
 inline const GenericLinkService::Options&
@@ -156,6 +243,12 @@
   m_options = options;
 }
 
+inline const GenericLinkService::Counters&
+GenericLinkService::getCounters() const
+{
+  return *this;
+}
+
 } // namespace face
 } // namespace nfd
 
diff --git a/daemon/face/lp-fragmenter.cpp b/daemon/face/lp-fragmenter.cpp
new file mode 100644
index 0000000..b54f7d5
--- /dev/null
+++ b/daemon/face/lp-fragmenter.cpp
@@ -0,0 +1,162 @@
+/* -*- 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 "lp-fragmenter.hpp"
+#include "link-service.hpp"
+#include <ndn-cxx/encoding/tlv.hpp>
+
+namespace nfd {
+namespace face {
+
+NFD_LOG_INIT("LpFragmenter");
+
+static_assert(lp::tlv::LpPacket < 253, "LpPacket TLV-TYPE must fit in 1 octet");
+static_assert(lp::tlv::Sequence < 253, "Sequence TLV-TYPE must fit in 1 octet");
+static_assert(lp::tlv::FragIndex < 253, "FragIndex TLV-TYPE must fit in 1 octet");
+static_assert(lp::tlv::FragCount < 253, "FragCount TLV-TYPE must fit in 1 octet");
+static_assert(lp::tlv::Fragment < 253, "Fragment TLV-TYPE must fit in 1 octet");
+
+/** \brief maximum overhead on a single fragment,
+ *         not counting other NDNLPv2 headers
+ */
+static const size_t MAX_SINGLE_FRAG_OVERHEAD =
+  1 + 9 + // LpPacket TLV-TYPE and TLV-LENGTH
+  1 + 1 + 8 + // Sequence TLV
+  1 + 9; // Fragment TLV-TYPE and TLV-LENGTH
+
+/** \brief maximum overhead of adding fragmentation to payload,
+ *         not counting other NDNLPv2 headers
+ */
+static const size_t MAX_FRAG_OVERHEAD =
+  1 + 9 + // LpPacket TLV-TYPE and TLV-LENGTH
+  1 + 1 + 8 + // Sequence TLV
+  1 + 1 + 8 + // FragIndex TLV
+  1 + 1 + 8 + // FragCount TLV
+  1 + 9; // Fragment TLV-TYPE and TLV-LENGTH
+
+LpFragmenter::Options::Options()
+  : nMaxFragments(400)
+{
+}
+
+LpFragmenter::LpFragmenter(const LpFragmenter::Options& options, const LinkService* linkService)
+  : m_options(options)
+  , m_linkService(linkService)
+{
+}
+
+void
+LpFragmenter::setOptions(const Options& options)
+{
+  m_options = options;
+}
+
+const LinkService*
+LpFragmenter::getLinkService() const
+{
+  return m_linkService;
+}
+
+std::tuple<bool, std::vector<lp::Packet>>
+LpFragmenter::fragmentPacket(const lp::Packet& packet, size_t mtu)
+{
+  BOOST_ASSERT(packet.has<lp::FragmentField>());
+  BOOST_ASSERT(!packet.has<lp::FragIndexField>());
+  BOOST_ASSERT(!packet.has<lp::FragCountField>());
+
+  if (MAX_SINGLE_FRAG_OVERHEAD + packet.wireEncode().size() <= mtu) {
+    // fast path: fragmentation not needed
+    // To qualify for fast path, the packet must have space for adding a sequence number,
+    // because another NDNLPv2 feature may require the sequence number.
+    return std::make_tuple(true, std::vector<lp::Packet>{packet});
+  }
+
+  ndn::Buffer::const_iterator netPktBegin, netPktEnd;
+  std::tie(netPktBegin, netPktEnd) = packet.get<lp::FragmentField>();
+  size_t netPktSize = std::distance(netPktBegin, netPktEnd);
+
+  // compute size of other NDNLPv2 headers to be placed on the first fragment
+  size_t firstHeaderSize = 0;
+  const Block& packetWire = packet.wireEncode();
+  if (packetWire.type() == lp::tlv::LpPacket) {
+    for (const Block& element : packetWire.elements()) {
+      if (element.type() != lp::tlv::Fragment) {
+        firstHeaderSize += element.size();
+      }
+    }
+  }
+
+  // compute payload size
+  if (MAX_FRAG_OVERHEAD + firstHeaderSize + 1 > mtu) { // 1-octet fragment
+    NFD_LOG_FACE_WARN("fragmentation error, MTU too small for first fragment: DROP");
+    return std::make_tuple(false, std::vector<lp::Packet>{});
+  }
+  size_t firstPayloadSize = std::min(netPktSize, mtu - firstHeaderSize - MAX_FRAG_OVERHEAD);
+  size_t payloadSize = mtu - MAX_FRAG_OVERHEAD;
+  size_t fragCount = 1 + ((netPktSize - firstPayloadSize) / payloadSize) +
+                     ((netPktSize - firstPayloadSize) % payloadSize != 0);
+
+  // compute FragCount
+  if (fragCount > m_options.nMaxFragments) {
+    NFD_LOG_FACE_WARN("fragmentation error, FragCount over limit: DROP");
+    return std::make_pair(false, std::vector<lp::Packet>{});
+  }
+
+  // populate fragments
+  std::vector<lp::Packet> frags(fragCount);
+  frags.front() = packet; // copy input packet to preserve other NDNLPv2 fields
+  size_t fragIndex = 0;
+  auto fragBegin = netPktBegin,
+       fragEnd = fragBegin + firstPayloadSize;
+  while (fragBegin < netPktEnd) {
+    lp::Packet& frag = frags[fragIndex];
+    frag.add<lp::FragIndexField>(fragIndex);
+    frag.add<lp::FragCountField>(fragCount);
+    frag.set<lp::FragmentField>(std::make_pair(fragBegin, fragEnd));
+    BOOST_ASSERT(frag.wireEncode().size() <= mtu);
+
+    ++fragIndex;
+    fragBegin = fragEnd;
+    fragEnd = std::min(netPktEnd, fragBegin + payloadSize);
+  }
+  BOOST_ASSERT(fragIndex == fragCount);
+
+  return std::make_pair(true, frags);
+}
+
+std::ostream&
+operator<<(std::ostream& os, const FaceLogHelper<LpFragmenter>& flh)
+{
+  if (flh.obj.getLinkService() == nullptr) {
+    os << "[id=0,local=unknown,remote=unknown] ";
+  }
+  else {
+    os << FaceLogHelper<LinkService>(*flh.obj.getLinkService());
+  }
+  return os;
+}
+
+} // namespace face
+} // namespace nfd
diff --git a/daemon/face/lp-fragmenter.hpp b/daemon/face/lp-fragmenter.hpp
new file mode 100644
index 0000000..8275d0f
--- /dev/null
+++ b/daemon/face/lp-fragmenter.hpp
@@ -0,0 +1,92 @@
+/* -*- 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/>.
+ */
+
+#ifndef NFD_DAEMON_FACE_LP_FRAGMENTER_HPP
+#define NFD_DAEMON_FACE_LP_FRAGMENTER_HPP
+
+#include "face-log.hpp"
+
+#include <ndn-cxx/lp/packet.hpp>
+
+namespace nfd {
+namespace face {
+
+class LinkService;
+
+/** \brief fragments network-layer packets into NDNLPv2 link-layer packets
+ *  \sa http://redmine.named-data.net/projects/nfd/wiki/NDNLPv2
+ */
+class LpFragmenter
+{
+public:
+  /** \brief Options that control the behavior of LpFragmenter
+   */
+  class Options
+  {
+  public:
+    Options();
+
+  public:
+    /** \brief maximum number of fragments in a packet
+     */
+    size_t nMaxFragments;
+  };
+
+  explicit
+  LpFragmenter(const Options& options = Options(), const LinkService* linkService = nullptr);
+
+  /** \brief set options for fragmenter
+   */
+  void
+  setOptions(const Options& options);
+
+  /** \return LinkService that owns this instance
+   *
+   *  This is only used for logging, and may be nullptr.
+   */
+  const LinkService*
+  getLinkService() const;
+
+  /** \brief fragments a network-layer packet into link-layer packets
+   *  \param packet an LpPacket that contains a network-layer packet;
+   *                must have Fragment field, must not have FragIndex and FragCount fields
+   *  \param mtu maximum allowable LpPacket size after fragmentation and sequence number assignment
+   *  \return whether fragmentation succeeded, fragmented packets without sequence number
+   */
+  std::tuple<bool, std::vector<lp::Packet>>
+  fragmentPacket(const lp::Packet& packet, size_t mtu);
+
+private:
+  Options m_options;
+  const LinkService* m_linkService;
+};
+
+std::ostream&
+operator<<(std::ostream& os, const FaceLogHelper<LpFragmenter>& flh);
+
+} // namespace face
+} // namespace nfd
+
+#endif // NFD_DAEMON_FACE_LP_FRAGMENTER_HPP
diff --git a/daemon/face/lp-reassembler.cpp b/daemon/face/lp-reassembler.cpp
new file mode 100644
index 0000000..88ef1c1
--- /dev/null
+++ b/daemon/face/lp-reassembler.cpp
@@ -0,0 +1,176 @@
+/* -*- 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 "lp-reassembler.hpp"
+#include "link-service.hpp"
+#include <numeric>
+
+namespace nfd {
+namespace face {
+
+NFD_LOG_INIT("LpReassembler");
+
+LpReassembler::Options::Options()
+  : nMaxFragments(400)
+  , reassemblyTimeout(time::milliseconds(500))
+{
+}
+
+LpReassembler::LpReassembler(const LpReassembler::Options& options, const LinkService* linkService)
+  : m_options(options)
+  , m_linkService(linkService)
+{
+}
+
+std::tuple<bool, Block, lp::Packet>
+LpReassembler::receiveFragment(Transport::EndpointId remoteEndpoint, const lp::Packet& packet)
+{
+  BOOST_ASSERT(packet.has<lp::FragmentField>());
+
+  static auto FALSE_RETURN = std::make_tuple(false, Block(), lp::Packet());
+
+  // read and check FragIndex and FragCount
+  uint64_t fragIndex = 0;
+  uint64_t fragCount = 1;
+  if (packet.has<lp::FragIndexField>()) {
+    fragIndex = packet.get<lp::FragIndexField>();
+  }
+  if (packet.has<lp::FragCountField>()) {
+    fragCount = packet.get<lp::FragCountField>();
+  }
+
+  if (fragIndex >= fragCount) {
+    NFD_LOG_FACE_WARN("reassembly error, FragIndex>=FragCount: DROP");
+    return FALSE_RETURN;
+  }
+
+  if (fragCount > m_options.nMaxFragments) {
+    NFD_LOG_FACE_WARN("reassembly error, FragCount over limit: DROP");
+    return FALSE_RETURN;
+  }
+
+  // check for fast path
+  if (fragIndex == 0 && fragCount == 1) {
+    ndn::Buffer::const_iterator fragBegin, fragEnd;
+    std::tie(fragBegin, fragEnd) = packet.get<lp::FragmentField>();
+    Block netPkt(&*fragBegin, std::distance(fragBegin, fragEnd));
+    return std::make_tuple(true, netPkt, packet);
+  }
+
+  // check Sequence and compute message identifier
+  if (!packet.has<lp::SequenceField>()) {
+    NFD_LOG_FACE_WARN("reassembly error, Sequence missing: DROP");
+    return FALSE_RETURN;
+  }
+  lp::Sequence messageIdentifier = packet.get<lp::SequenceField>() - fragIndex;
+  Key key = std::make_tuple(remoteEndpoint, messageIdentifier);
+
+  // add to PartialPacket
+  PartialPacket& pp = m_partialPackets[key];
+  if (pp.fragCount == 0) { // new PartialPacket
+    pp.fragCount = fragCount;
+    pp.nReceivedFragments = 0;
+    pp.fragments.resize(fragCount);
+  }
+  else {
+    if (fragCount != pp.fragCount) {
+      NFD_LOG_FACE_WARN("reassembly error, FragCount changed: DROP");
+      return FALSE_RETURN;
+    }
+  }
+
+  if (pp.fragments[fragIndex].has<lp::SequenceField>()) {
+    NFD_LOG_FACE_TRACE("fragment already received: DROP");
+    return FALSE_RETURN;
+  }
+
+  pp.fragments[fragIndex] = packet;
+  ++pp.nReceivedFragments;
+
+  // check complete condition
+  if (pp.nReceivedFragments == pp.fragCount) {
+    Block reassembled = doReassembly(key);
+    lp::Packet firstFrag(std::move(pp.fragments[0]));
+    m_partialPackets.erase(key);
+    return std::make_tuple(true, reassembled, firstFrag);
+  }
+
+  // set drop timer
+  pp.dropTimer = scheduler::schedule(m_options.reassemblyTimeout,
+                                     bind(&LpReassembler::timeoutPartialPacket, this, key));
+
+  return FALSE_RETURN;
+}
+
+Block
+LpReassembler::doReassembly(const Key& key)
+{
+  PartialPacket& pp = m_partialPackets[key];
+
+  size_t payloadSize = std::accumulate(pp.fragments.begin(), pp.fragments.end(), 0,
+    [&] (size_t sum, const lp::Packet& pkt) -> size_t {
+      ndn::Buffer::const_iterator fragBegin, fragEnd;
+      std::tie(fragBegin, fragEnd) = pkt.get<lp::FragmentField>();
+      return sum + std::distance(fragBegin, fragEnd);
+    });
+
+  ndn::Buffer fragBuffer(payloadSize);
+  ndn::Buffer::iterator it = fragBuffer.begin();
+
+  for (const lp::Packet& frag : pp.fragments) {
+    ndn::Buffer::const_iterator fragBegin, fragEnd;
+    std::tie(fragBegin, fragEnd) = frag.get<lp::FragmentField>();
+    it = std::copy(fragBegin, fragEnd, it);
+  }
+
+  return Block(&*(fragBuffer.cbegin()), std::distance(fragBuffer.cbegin(), fragBuffer.cend()));
+}
+
+void
+LpReassembler::timeoutPartialPacket(const Key& key)
+{
+  auto it = m_partialPackets.find(key);
+  if (it == m_partialPackets.end()) {
+    return;
+  }
+
+  this->beforeTimeout(std::get<0>(key), it->second.nReceivedFragments);
+  m_partialPackets.erase(it);
+}
+
+std::ostream&
+operator<<(std::ostream& os, const FaceLogHelper<LpReassembler>& flh)
+{
+  if (flh.obj.getLinkService() == nullptr) {
+    os << "[id=0,local=unknown,remote=unknown] ";
+  }
+  else {
+    os << FaceLogHelper<LinkService>(*flh.obj.getLinkService());
+  }
+  return os;
+}
+
+} // namespace face
+} // namespace nfd
diff --git a/daemon/face/lp-reassembler.hpp b/daemon/face/lp-reassembler.hpp
new file mode 100644
index 0000000..fd0d874
--- /dev/null
+++ b/daemon/face/lp-reassembler.hpp
@@ -0,0 +1,160 @@
+/* -*- 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/>.
+ */
+
+#ifndef NFD_DAEMON_FACE_LP_REASSEMBLER_HPP
+#define NFD_DAEMON_FACE_LP_REASSEMBLER_HPP
+
+#include "core/scheduler.hpp"
+#include "face-log.hpp"
+#include "transport.hpp"
+
+#include <ndn-cxx/lp/packet.hpp>
+
+namespace nfd {
+namespace face {
+
+class LinkService;
+
+/** \brief reassembles fragmented network-layer packets
+ *  \sa http://redmine.named-data.net/projects/nfd/wiki/NDNLPv2
+ */
+class LpReassembler : noncopyable
+{
+public:
+  /** \brief Options that control the behavior of LpReassembler
+   */
+  class Options
+  {
+  public:
+    Options();
+
+  public:
+    /** \brief maximum number of fragments in a packet
+     *
+     *  LpPackets with FragCount over this limit are dropped.
+     */
+    size_t nMaxFragments;
+
+    /** \brief timeout before a partially reassembled packet is dropped
+     */
+    time::nanoseconds reassemblyTimeout;
+  };
+
+  explicit
+  LpReassembler(const Options& options = Options(), const LinkService* linkService = nullptr);
+
+  /** \brief set options for reassembler
+   */
+  void
+  setOptions(const Options& options);
+
+  /** \return LinkService that owns this instance
+   *
+   *  This is only used for logging, and may be nullptr.
+   */
+  const LinkService*
+  getLinkService() const;
+
+  /** \brief adds received fragment to buffer
+   *  \param remoteEndpoint endpoint whose sends the packet
+   *  \param packet received fragment;
+   *                must have Fragment field
+   *  \return whether network-layer packet has been completely received,
+   *          the reassembled network-layer packet,
+   *          and the first fragment for inspecting other NDNLPv2 headers
+   *  \throw tlv::Error packet is malformed
+   */
+  std::tuple<bool, Block, lp::Packet>
+  receiveFragment(Transport::EndpointId remoteEndpoint, const lp::Packet& packet);
+
+  /** \brief count of partial packets
+   */
+  size_t
+  size() const;
+
+  /** \brief signals before a partial packet is dropped due to timeout
+   *
+   *  If a partial packet is incomplete and no new fragment is received
+   *  within Options::reassemblyTimeout, it would be dropped due to timeout.
+   *  Before it's erased, this signal is emitted with the remote endpoint,
+   *  and the number of fragments being dropped.
+   */
+  signal::Signal<LpReassembler, Transport::EndpointId, size_t> beforeTimeout;
+
+private:
+  /** \brief holds all fragments of packet until reassembled
+   */
+  struct PartialPacket
+  {
+    std::vector<lp::Packet> fragments;
+    size_t fragCount; ///< total fragments
+    size_t nReceivedFragments; ///< number of received fragments
+    scheduler::ScopedEventId dropTimer;
+  };
+
+  /** \brief index key for PartialPackets
+   */
+  typedef std::tuple<
+    Transport::EndpointId, // remoteEndpoint
+    lp::Sequence // message identifier (sequence of the first fragment)
+  > Key;
+
+  Block
+  doReassembly(const Key& key);
+
+  void
+  timeoutPartialPacket(const Key& key);
+
+private:
+  Options m_options;
+  std::map<Key, PartialPacket> m_partialPackets;
+  const LinkService* m_linkService;
+};
+
+std::ostream&
+operator<<(std::ostream& os, const FaceLogHelper<LpReassembler>& flh);
+
+inline void
+LpReassembler::setOptions(const Options& options)
+{
+  m_options = options;
+}
+
+inline const LinkService*
+LpReassembler::getLinkService() const
+{
+  return m_linkService;
+}
+
+inline size_t
+LpReassembler::size() const
+{
+  return m_partialPackets.size();
+}
+
+} // namespace face
+} // namespace nfd
+
+#endif // NFD_DAEMON_FACE_LP_REASSEMBLER_HPP