diff --git a/src/core/coap/coap_server.cpp b/src/core/coap/coap_server.cpp
index d6a52e570..3e80530fc 100644
--- a/src/core/coap/coap_server.cpp
+++ b/src/core/coap/coap_server.cpp
@@ -105,6 +105,30 @@ ThreadError Server::SendMessage(Message &aMessage, const Ip6::MessageInfo &aMess
     return mSender(this, aMessage, aMessageInfo);
 }
 
+ThreadError Server::SendEmptyAck(const Header &aRequestHeader, const Ip6::MessageInfo &aMessageInfo)
+{
+    ThreadError error = kThreadError_None;
+    Coap::Header responseHeader;
+    Message *message = NULL;
+
+    VerifyOrExit(aRequestHeader.GetType() == kCoapTypeConfirmable, error = kThreadError_InvalidArgs);
+
+    responseHeader.SetDefaultResponseHeader(aRequestHeader);
+
+    VerifyOrExit((message = NewMessage(responseHeader)) != NULL, error = kThreadError_NoBufs);
+
+    SuccessOrExit(error = SendMessage(*message, aMessageInfo));
+
+exit:
+
+    if (error != kThreadError_None && message != NULL)
+    {
+        message->Free();
+    }
+
+    return error;
+}
+
 void Server::ProcessReceivedMessage(Message &aMessage, const Ip6::MessageInfo &aMessageInfo)
 {
     Header header;
diff --git a/src/core/coap/coap_server.hpp b/src/core/coap/coap_server.hpp
index d372e75b6..acf7c2191 100644
--- a/src/core/coap/coap_server.hpp
+++ b/src/core/coap/coap_server.hpp
@@ -178,6 +178,19 @@ public:
      */
     ThreadError SendMessage(Message &aMessage, const Ip6::MessageInfo &aMessageInfo);
 
+    /**
+     * This method sends a CoAP ACK message on which a dummy CoAP response is piggybacked.
+     *
+     * @param[in]  aRequestHeader  A reference to the CoAP Header that was used in CoAP request.
+     * @param[in]  aMessageInfo    The message info corresponding to the CoAP request.
+     *
+     * @retval kThreadError_None         Successfully enqueued the CoAP response message.
+     * @retval kThreadError_NoBufs       Insufficient buffers available to send the CoAP response.
+     * @retval kThreadError_InvalidArgs  The @p aRequestHeader header is not of confirmable type.
+     *
+     */
+    ThreadError SendEmptyAck(const Header &aRequestHeader, const Ip6::MessageInfo &aMessageInfo);
+
     /**
      * This method sets CoAP server's port number.
      *
diff --git a/src/core/meshcop/commissioner.cpp b/src/core/meshcop/commissioner.cpp
index 4ef7a7d9e..3bdb3ce7c 100644
--- a/src/core/meshcop/commissioner.cpp
+++ b/src/core/meshcop/commissioner.cpp
@@ -758,37 +758,14 @@ void Commissioner::HandleDatasetChanged(Coap::Header &aHeader, Message &aMessage
     otLogInfoMeshCoP("received dataset changed");
     (void)aMessage;
 
-    SendDatasetChangedResponse(aHeader, aMessageInfo);
+    SuccessOrExit(mCoapServer.SendEmptyAck(aHeader, aMessageInfo));
+
+    otLogInfoMeshCoP("sent dataset changed acknowledgment");
 
 exit:
     otLogFuncExit();
 }
 
-void Commissioner::SendDatasetChangedResponse(const Coap::Header &aRequestHeader, const Ip6::MessageInfo &aMessageInfo)
-{
-    ThreadError error = kThreadError_None;
-    Coap::Header responseHeader;
-    Message *message;
-
-    otLogFuncEntry();
-    VerifyOrExit((message = mCoapServer.NewMessage(0)) != NULL, error = kThreadError_NoBufs);
-
-    responseHeader.SetDefaultResponseHeader(aRequestHeader);
-    SuccessOrExit(error = message->Append(responseHeader.GetBytes(), responseHeader.GetLength()));
-    SuccessOrExit(error = mCoapServer.SendMessage(*message, aMessageInfo));
-
-    otLogInfoMeshCoP("Sent dataset changed acknowledgment");
-
-exit:
-
-    if (error != kThreadError_None && message != NULL)
-    {
-        message->Free();
-    }
-
-    otLogFuncExit();
-}
-
 void Commissioner::HandleJoinerFinalize(void *aContext, otCoapHeader *aHeader, otMessage aMessage,
                                         const otMessageInfo *aMessageInfo)
 {
diff --git a/src/core/meshcop/commissioner.hpp b/src/core/meshcop/commissioner.hpp
index 490660fea..8b08a41ea 100644
--- a/src/core/meshcop/commissioner.hpp
+++ b/src/core/meshcop/commissioner.hpp
@@ -224,7 +224,6 @@ private:
     static ThreadError SendRelayTransmit(void *aContext, Message &aMessage, const Ip6::MessageInfo &aMessageInfo);
     ThreadError SendRelayTransmit(Message &aMessage, const Ip6::MessageInfo &aMessageInfo);
 
-    void SendDatasetChangedResponse(const Coap::Header &aRequestHeader, const Ip6::MessageInfo &aMessageInfo);
     ThreadError SendCommissionerSet(void);
     ThreadError SendPetition(void);
     ThreadError SendKeepAlive(void);
diff --git a/src/core/meshcop/energy_scan_client.cpp b/src/core/meshcop/energy_scan_client.cpp
index 1962cedf7..bebe26219 100644
--- a/src/core/meshcop/energy_scan_client.cpp
+++ b/src/core/meshcop/energy_scan_client.cpp
@@ -133,6 +133,7 @@ void EnergyScanClient::HandleReport(void *aContext, otCoapHeader *aHeader, otMes
 void EnergyScanClient::HandleReport(Coap::Header &aHeader, Message &aMessage, const Ip6::MessageInfo &aMessageInfo)
 {
     MeshCoP::ChannelMask0Tlv channelMask;
+    Ip6::MessageInfo responseInfo(aMessageInfo);
 
     OT_TOOL_PACKED_BEGIN
     struct
@@ -157,36 +158,13 @@ void EnergyScanClient::HandleReport(Coap::Header &aHeader, Message &aMessage, co
         mCallback(channelMask.GetMask(), energyList.list, energyList.tlv.GetLength(), mContext);
     }
 
-    SendResponse(aHeader, aMessageInfo);
+    memset(&responseInfo.mSockAddr, 0, sizeof(responseInfo.mSockAddr));
+    SuccessOrExit(mCoapServer.SendEmptyAck(aHeader, responseInfo));
+
+    otLogInfoMeshCoP("sent energy scan report response");
 
 exit:
     return;
 }
 
-ThreadError EnergyScanClient::SendResponse(const Coap::Header &aRequestHeader, const Ip6::MessageInfo &aRequestInfo)
-{
-    ThreadError error = kThreadError_None;
-    Message *message;
-    Coap::Header responseHeader;
-    Ip6::MessageInfo responseInfo(aRequestInfo);
-
-    VerifyOrExit((message = mCoapServer.NewMessage(0)) != NULL, error = kThreadError_NoBufs);
-
-    responseHeader.SetDefaultResponseHeader(aRequestHeader);
-
-    SuccessOrExit(error = message->Append(responseHeader.GetBytes(), responseHeader.GetLength()));
-
-    memset(&responseInfo.mSockAddr, 0, sizeof(responseInfo.mSockAddr));
-    SuccessOrExit(error = mCoapServer.SendMessage(*message, responseInfo));
-
-exit:
-
-    if (error != kThreadError_None && message != NULL)
-    {
-        message->Free();
-    }
-
-    return error;
-}
-
 }  // namespace Thread
diff --git a/src/core/meshcop/energy_scan_client.hpp b/src/core/meshcop/energy_scan_client.hpp
index 1cf1c1b9a..7049962e4 100644
--- a/src/core/meshcop/energy_scan_client.hpp
+++ b/src/core/meshcop/energy_scan_client.hpp
@@ -82,8 +82,6 @@ private:
                              const otMessageInfo *aMessageInfo);
     void HandleReport(Coap::Header &aHeader, Message &aMessage, const Ip6::MessageInfo &aMessageInfo);
 
-    ThreadError SendResponse(const Coap::Header &aRequestHeader, const Ip6::MessageInfo &aRequestMessageInfo);
-
     otCommissionerEnergyReportCallback mCallback;
     void *mContext;
 
diff --git a/src/core/meshcop/panid_query_client.cpp b/src/core/meshcop/panid_query_client.cpp
index 75a2f7e87..53c212954 100644
--- a/src/core/meshcop/panid_query_client.cpp
+++ b/src/core/meshcop/panid_query_client.cpp
@@ -119,6 +119,7 @@ void PanIdQueryClient::HandleConflict(Coap::Header &aHeader, Message &aMessage,
 {
     MeshCoP::PanIdTlv panId;
     MeshCoP::ChannelMask0Tlv channelMask;
+    Ip6::MessageInfo responseInfo(aMessageInfo);
 
     VerifyOrExit(aHeader.GetType() == kCoapTypeConfirmable &&
                  aHeader.GetCode() == kCoapRequestPost, ;);
@@ -136,37 +137,13 @@ void PanIdQueryClient::HandleConflict(Coap::Header &aHeader, Message &aMessage,
         mCallback(panId.GetPanId(), channelMask.GetMask(), mContext);
     }
 
-    SendConflictResponse(aHeader, aMessageInfo);
+    memset(&responseInfo.mSockAddr, 0, sizeof(responseInfo.mSockAddr));
+    SuccessOrExit(mCoapServer.SendEmptyAck(aHeader, responseInfo));
+
+    otLogInfoMeshCoP("sent panid query conflict response");
 
 exit:
     return;
 }
 
-ThreadError PanIdQueryClient::SendConflictResponse(const Coap::Header &aRequestHeader,
-                                                   const Ip6::MessageInfo &aRequestInfo)
-{
-    ThreadError error = kThreadError_None;
-    Message *message;
-    Coap::Header responseHeader;
-    Ip6::MessageInfo responseInfo(aRequestInfo);
-
-    VerifyOrExit((message = mCoapServer.NewMessage(0)) != NULL, error = kThreadError_NoBufs);
-
-    responseHeader.SetDefaultResponseHeader(aRequestHeader);
-
-    SuccessOrExit(error = message->Append(responseHeader.GetBytes(), responseHeader.GetLength()));
-
-    memset(&responseInfo.mSockAddr, 0, sizeof(responseInfo.mSockAddr));
-    SuccessOrExit(error = mCoapServer.SendMessage(*message, responseInfo));
-
-exit:
-
-    if (error != kThreadError_None && message != NULL)
-    {
-        message->Free();
-    }
-
-    return error;
-}
-
 }  // namespace Thread
diff --git a/src/core/meshcop/panid_query_client.hpp b/src/core/meshcop/panid_query_client.hpp
index 1423e4269..7050b7e75 100644
--- a/src/core/meshcop/panid_query_client.hpp
+++ b/src/core/meshcop/panid_query_client.hpp
@@ -80,8 +80,6 @@ private:
                                const otMessageInfo *aMessageInfo);
     void HandleConflict(Coap::Header &aHeader, Message &aMessage, const Ip6::MessageInfo &aMessageInfo);
 
-    ThreadError SendConflictResponse(const Coap::Header &aRequestHeader, const Ip6::MessageInfo &aRequestMessageInfo);
-
     otCommissionerPanIdConflictCallback mCallback;
     void *mContext;
 
diff --git a/src/core/thread/address_resolver.cpp b/src/core/thread/address_resolver.cpp
index 131a7591e..bc4194b52 100644
--- a/src/core/thread/address_resolver.cpp
+++ b/src/core/thread/address_resolver.cpp
@@ -281,7 +281,12 @@ void AddressResolver::HandleAddressNotification(Coap::Header &aHeader, Message &
             mCache[i].mTimeout = 0;
             mCache[i].mFailures = 0;
             mCache[i].mState = Cache::kStateCached;
-            SendAddressNotificationResponse(aHeader, aMessageInfo);
+
+            if (mCoapServer.SendEmptyAck(aHeader, aMessageInfo) == kThreadError_None)
+            {
+                otLogInfoArp("Sent address notification acknowledgment");
+            }
+
             mMeshForwarder.HandleResolved(*targetTlv.GetTarget(), kThreadError_None);
             break;
         }
@@ -291,32 +296,6 @@ exit:
     return;
 }
 
-void AddressResolver::SendAddressNotificationResponse(const Coap::Header &aRequestHeader,
-                                                      const Ip6::MessageInfo &aRequestInfo)
-{
-    ThreadError error;
-    Message *message;
-    Coap::Header responseHeader;
-    Ip6::MessageInfo responseInfo(aRequestInfo);
-
-    VerifyOrExit((message = mCoapServer.NewMessage(0)) != NULL, error = kThreadError_NoBufs);
-
-    responseHeader.SetDefaultResponseHeader(aRequestHeader);
-
-    SuccessOrExit(error = message->Append(responseHeader.GetBytes(), responseHeader.GetLength()));
-
-    SuccessOrExit(error = mCoapServer.SendMessage(*message, responseInfo));
-
-    otLogInfoArp("Sent address notification acknowledgment");
-
-exit:
-
-    if (error != kThreadError_None && message != NULL)
-    {
-        message->Free();
-    }
-}
-
 ThreadError AddressResolver::SendAddressError(const ThreadTargetTlv &aTarget, const ThreadMeshLocalEidTlv &aEid,
                                               const Ip6::Address *aDestination)
 {
@@ -363,32 +342,6 @@ exit:
     return error;
 }
 
-void AddressResolver::SendAddressErrorResponse(const Coap::Header &aRequestHeader,
-                                               const Ip6::MessageInfo &aRequestInfo)
-{
-    ThreadError error;
-    Message *message;
-    Coap::Header responseHeader;
-    Ip6::MessageInfo responseInfo(aRequestInfo);
-
-    VerifyOrExit((message = mCoapServer.NewMessage(0)) != NULL, error = kThreadError_NoBufs);
-
-    responseHeader.SetDefaultResponseHeader(aRequestHeader);
-
-    SuccessOrExit(error = message->Append(responseHeader.GetBytes(), responseHeader.GetLength()));
-
-    SuccessOrExit(error = mCoapServer.SendMessage(*message, responseInfo));
-
-    otLogInfoArp("Sent address error notification acknowledgment");
-
-exit:
-
-    if (error != kThreadError_None && message != NULL)
-    {
-        message->Free();
-    }
-}
-
 void AddressResolver::HandleAddressError(void *aContext, otCoapHeader *aHeader, otMessage aMessage,
                                          const otMessageInfo *aMessageInfo)
 {
@@ -415,7 +368,10 @@ void AddressResolver::HandleAddressError(Coap::Header &aHeader, Message &aMessag
 
     if (!aMessageInfo.GetSockAddr().IsMulticast())
     {
-        SendAddressErrorResponse(aHeader, aMessageInfo);
+        if (mCoapServer.SendEmptyAck(aHeader, aMessageInfo) == kThreadError_None)
+        {
+            otLogInfoArp("Sent address error notification acknowledgment");
+        }
     }
 
     SuccessOrExit(error = ThreadTlv::GetTlv(aMessage, ThreadTlv::kTarget, sizeof(targetTlv), targetTlv));
diff --git a/src/core/thread/address_resolver_ftd.hpp b/src/core/thread/address_resolver_ftd.hpp
index ee6b9cfab..1c88db7f3 100644
--- a/src/core/thread/address_resolver_ftd.hpp
+++ b/src/core/thread/address_resolver_ftd.hpp
@@ -154,8 +154,6 @@ private:
     void SendAddressQueryResponse(const ThreadTargetTlv &aTargetTlv, const ThreadMeshLocalEidTlv &aMlEidTlv,
                                   const ThreadLastTransactionTimeTlv *aLastTransactionTimeTlv,
                                   const Ip6::Address &aDestination);
-    void SendAddressErrorResponse(const Coap::Header &aRequestHeader, const Ip6::MessageInfo &aRequestInfo);
-    void SendAddressNotificationResponse(const Coap::Header &aRequestHeader, const Ip6::MessageInfo &aRequestInfo);
 
     static void HandleUdpReceive(void *aContext, otMessage aMessage, const otMessageInfo *aMessageInfo);
 
diff --git a/src/core/thread/announce_begin_server.cpp b/src/core/thread/announce_begin_server.cpp
index 2005fa1ed..df4548ec9 100644
--- a/src/core/thread/announce_begin_server.cpp
+++ b/src/core/thread/announce_begin_server.cpp
@@ -104,6 +104,7 @@ void AnnounceBeginServer::HandleRequest(Coap::Header &aHeader, Message &aMessage
     MeshCoP::ChannelMask0Tlv channelMask;
     MeshCoP::CountTlv count;
     MeshCoP::PeriodTlv period;
+    Ip6::MessageInfo responseInfo(aMessageInfo);
 
     VerifyOrExit(aHeader.GetCode() == kCoapRequestPost, ;);
 
@@ -118,40 +119,13 @@ void AnnounceBeginServer::HandleRequest(Coap::Header &aHeader, Message &aMessage
 
     SendAnnounce(channelMask.GetMask(), count.GetCount(), period.GetPeriod());
 
-    SendResponse(aHeader, aMessageInfo);
-
-exit:
-    return;
-}
-
-ThreadError AnnounceBeginServer::SendResponse(const Coap::Header &aRequestHeader, const Ip6::MessageInfo &aRequestInfo)
-{
-    ThreadError error = kThreadError_None;
-    Message *message = NULL;
-    Coap::Header responseHeader;
-    Ip6::MessageInfo responseInfo(aRequestInfo);
-
-    VerifyOrExit(aRequestHeader.GetType() == kCoapTypeConfirmable, ;);
-
-    VerifyOrExit((message = mCoapServer.NewMessage(0)) != NULL, error = kThreadError_NoBufs);
-
-    responseHeader.SetDefaultResponseHeader(aRequestHeader);
-
-    SuccessOrExit(error = message->Append(responseHeader.GetBytes(), responseHeader.GetLength()));
-
     memset(&responseInfo.mSockAddr, 0, sizeof(responseInfo.mSockAddr));
-    SuccessOrExit(error = mCoapServer.SendMessage(*message, responseInfo));
+    SuccessOrExit(mCoapServer.SendEmptyAck(aHeader, responseInfo));
 
     otLogInfoMeshCoP("sent announce begin response");
 
 exit:
-
-    if (error != kThreadError_None && message != NULL)
-    {
-        message->Free();
-    }
-
-    return error;
+    return;
 }
 
 void AnnounceBeginServer::HandleTimer(void *aContext)
diff --git a/src/core/thread/announce_begin_server.hpp b/src/core/thread/announce_begin_server.hpp
index 9b30cc78a..667890c5f 100644
--- a/src/core/thread/announce_begin_server.hpp
+++ b/src/core/thread/announce_begin_server.hpp
@@ -91,8 +91,6 @@ private:
                               const otMessageInfo *aMessageInfo);
     void HandleRequest(Coap::Header &aHeader, Message &aMessage, const Ip6::MessageInfo &aMessageInfo);
 
-    ThreadError SendResponse(const Coap::Header &aRequestHeader, const Ip6::MessageInfo &aRequestMessageInfo);
-
     static void HandleTimer(void *aContext);
     void HandleTimer(void);
 
diff --git a/src/core/thread/energy_scan_server.cpp b/src/core/thread/energy_scan_server.cpp
index 9504bca11..280fdd6c8 100644
--- a/src/core/thread/energy_scan_server.cpp
+++ b/src/core/thread/energy_scan_server.cpp
@@ -79,6 +79,7 @@ void EnergyScanServer::HandleRequest(Coap::Header &aHeader, Message &aMessage, c
     MeshCoP::PeriodTlv period;
     MeshCoP::ScanDurationTlv scanDuration;
     MeshCoP::ChannelMask0Tlv channelMask;
+    Ip6::MessageInfo responseInfo(aMessageInfo);
 
     VerifyOrExit(aHeader.GetCode() == kCoapRequestPost, ;);
 
@@ -92,7 +93,7 @@ void EnergyScanServer::HandleRequest(Coap::Header &aHeader, Message &aMessage, c
     VerifyOrExit(scanDuration.IsValid(), ;);
 
     SuccessOrExit(MeshCoP::Tlv::GetTlv(aMessage, MeshCoP::Tlv::kChannelMask, sizeof(channelMask), channelMask));
-    VerifyOrExit(channelMask.IsValid(),);
+    VerifyOrExit(channelMask.IsValid(), ;);
 
     mChannelMask = channelMask.GetMask();
     mChannelMaskCurrent = mChannelMask;
@@ -104,40 +105,14 @@ void EnergyScanServer::HandleRequest(Coap::Header &aHeader, Message &aMessage, c
     mTimer.Start(kScanDelay);
 
     mCommissioner = aMessageInfo.GetPeerAddr();
-    SendResponse(aHeader, aMessageInfo);
-
-exit:
-    return;
-}
-
-ThreadError EnergyScanServer::SendResponse(const Coap::Header &aRequestHeader, const Ip6::MessageInfo &aRequestInfo)
-{
-    ThreadError error = kThreadError_None;
-    Message *message = NULL;
-    Coap::Header responseHeader;
-    Ip6::MessageInfo responseInfo(aRequestInfo);
-
-    VerifyOrExit(aRequestHeader.GetType() == kCoapTypeConfirmable, ;);
-
-    VerifyOrExit((message = mCoapServer.NewMessage(0)) != NULL, error = kThreadError_NoBufs);
-
-    responseHeader.SetDefaultResponseHeader(aRequestHeader);
-
-    SuccessOrExit(error = message->Append(responseHeader.GetBytes(), responseHeader.GetLength()));
 
     memset(&responseInfo.mSockAddr, 0, sizeof(responseInfo.mSockAddr));
-    SuccessOrExit(error = mCoapServer.SendMessage(*message, responseInfo));
+    SuccessOrExit(mCoapServer.SendEmptyAck(aHeader, responseInfo));
 
     otLogInfoMeshCoP("sent energy scan query response");
 
 exit:
-
-    if (error != kThreadError_None && message != NULL)
-    {
-        message->Free();
-    }
-
-    return error;
+    return;
 }
 
 void EnergyScanServer::HandleTimer(void *aContext)
diff --git a/src/core/thread/energy_scan_server.hpp b/src/core/thread/energy_scan_server.hpp
index 8fecce7d6..de37561f4 100644
--- a/src/core/thread/energy_scan_server.hpp
+++ b/src/core/thread/energy_scan_server.hpp
@@ -84,7 +84,6 @@ private:
     void HandleNetifStateChanged(uint32_t aFlags);
 
     ThreadError SendReport(void);
-    ThreadError SendResponse(const Coap::Header &aRequestHeader, const Ip6::MessageInfo &aRequestMessageInfo);
 
     Ip6::Address mCommissioner;
     uint32_t mChannelMask;
diff --git a/src/core/thread/mle_router.cpp b/src/core/thread/mle_router.cpp
index f02b1fdda..830c7102e 100644
--- a/src/core/thread/mle_router.cpp
+++ b/src/core/thread/mle_router.cpp
@@ -3990,34 +3990,13 @@ void MleRouter::HandleAddressRelease(Coap::Header &aHeader, Message &aMessage,
                  memcmp(&router->mMacAddr, macAddr64Tlv.GetMacAddr(), sizeof(router->mMacAddr)) == 0,);
 
     ReleaseRouterId(routerId);
-    SendAddressReleaseResponse(aHeader, aMessageInfo);
 
-exit:
-    {}
-}
-
-void MleRouter::SendAddressReleaseResponse(const Coap::Header &aRequestHeader, const Ip6::MessageInfo &aMessageInfo)
-{
-    ThreadError error = kThreadError_None;
-    Coap::Header responseHeader;
-    Message *message;
-
-    VerifyOrExit((message = mCoapServer.NewMessage(0)) != NULL, error = kThreadError_NoBufs);
-
-    responseHeader.SetDefaultResponseHeader(aRequestHeader);
-
-    SuccessOrExit(error = message->Append(responseHeader.GetBytes(), responseHeader.GetLength()));
-
-    SuccessOrExit(error = mCoapServer.SendMessage(*message, aMessageInfo));
+    SuccessOrExit(mCoapServer.SendEmptyAck(aHeader, aMessageInfo));
 
     otLogInfoMle("Sent address release response");
 
 exit:
-
-    if (error != kThreadError_None && message != NULL)
-    {
-        message->Free();
-    }
+    {}
 }
 
 void MleRouter::FillConnectivityTlv(ConnectivityTlv &aTlv)
diff --git a/src/core/thread/mle_router_ftd.hpp b/src/core/thread/mle_router_ftd.hpp
index b557cc233..1130c48a1 100644
--- a/src/core/thread/mle_router_ftd.hpp
+++ b/src/core/thread/mle_router_ftd.hpp
@@ -746,7 +746,6 @@ private:
     ThreadError SendAddressRelease(void);
     void SendAddressSolicitResponse(const Coap::Header &aRequest, uint8_t aRouterId,
                                     const Ip6::MessageInfo &aMessageInfo);
-    void SendAddressReleaseResponse(const Coap::Header &aRequestHeader, const Ip6::MessageInfo &aMessageInfo);
     ThreadError SendAdvertisement(void);
     ThreadError SendLinkRequest(Neighbor *aNeighbor);
     ThreadError SendLinkAccept(const Ip6::MessageInfo &aMessageInfo, Neighbor *aNeighbor,
diff --git a/src/core/thread/network_data_leader_ftd.cpp b/src/core/thread/network_data_leader_ftd.cpp
index 113e4338f..3b3a1128e 100644
--- a/src/core/thread/network_data_leader_ftd.cpp
+++ b/src/core/thread/network_data_leader_ftd.cpp
@@ -167,7 +167,9 @@ void Leader::HandleServerData(Coap::Header &aHeader, Message &aMessage,
                             networkData.GetTlvs(), networkData.GetLength());
     }
 
-    SendServerDataResponse(aHeader, aMessageInfo, NULL, 0);
+    SuccessOrExit(mCoapServer.SendEmptyAck(aHeader, aMessageInfo));
+
+    otLogInfoNetData("Sent network data registration acknowledgment");
 
 exit:
     return;
@@ -289,37 +291,6 @@ void Leader::HandleCommissioningGet(Coap::Header &aHeader, Message &aMessage, co
     SendCommissioningGetResponse(aHeader, aMessageInfo, tlvs, length);
 }
 
-void Leader::SendServerDataResponse(const Coap::Header &aRequestHeader, const Ip6::MessageInfo &aMessageInfo,
-                                    const uint8_t *aTlvs, uint8_t aTlvsLength)
-{
-    ThreadError error = kThreadError_None;
-    Coap::Header responseHeader;
-    Message *message;
-
-    VerifyOrExit((message = mCoapServer.NewMessage(0)) != NULL, error = kThreadError_NoBufs);
-
-    responseHeader.SetDefaultResponseHeader(aRequestHeader);
-
-    if (aTlvsLength > 0)
-    {
-        responseHeader.SetPayloadMarker();
-    }
-
-    SuccessOrExit(error = message->Append(responseHeader.GetBytes(), responseHeader.GetLength()));
-    SuccessOrExit(error = message->Append(aTlvs, aTlvsLength));
-
-    SuccessOrExit(error = mCoapServer.SendMessage(*message, aMessageInfo));
-
-    otLogInfoNetData("Sent network data registration acknowledgment");
-
-exit:
-
-    if (error != kThreadError_None && message != NULL)
-    {
-        message->Free();
-    }
-}
-
 void Leader::SendCommissioningGetResponse(const Coap::Header &aRequestHeader, const Ip6::MessageInfo &aMessageInfo,
                                           uint8_t *aTlvs, uint8_t aLength)
 {
diff --git a/src/core/thread/network_data_leader_ftd.hpp b/src/core/thread/network_data_leader_ftd.hpp
index 1a1866e3f..5ab8278c6 100644
--- a/src/core/thread/network_data_leader_ftd.hpp
+++ b/src/core/thread/network_data_leader_ftd.hpp
@@ -144,8 +144,6 @@ private:
     static void HandleServerData(void *aContext, otCoapHeader *aHeader, otMessage aMessage,
                                  const otMessageInfo *aMessageInfo);
     void HandleServerData(Coap::Header &aHeader, Message &aMessage, const Ip6::MessageInfo &aMessageInfo);
-    void SendServerDataResponse(const Coap::Header &aRequestHeader, const Ip6::MessageInfo &aMessageInfo,
-                                const uint8_t *aTlvs, uint8_t aTlvsLength);
 
     static void HandleTimer(void *aContext);
     void HandleTimer(void);
diff --git a/src/core/thread/network_diagnostic.cpp b/src/core/thread/network_diagnostic.cpp
index 681aaa7f3..28ef9745e 100644
--- a/src/core/thread/network_diagnostic.cpp
+++ b/src/core/thread/network_diagnostic.cpp
@@ -81,31 +81,6 @@ void NetworkDiagnostic::SetReceiveDiagnosticGetCallback(otReceiveDiagnosticGetCa
     mReceiveDiagnosticGetCallbackContext = aCallbackContext;
 }
 
-ThreadError NetworkDiagnostic::SendEmptyAck(Coap::Header &aHeader, const Ip6::MessageInfo &aMessageInfo)
-{
-    ThreadError error = kThreadError_None;
-    Message *message = NULL;
-    Coap::Header header;
-    Ip6::MessageInfo messageInfo(aMessageInfo);
-
-    VerifyOrExit((message = mCoapServer.NewMessage(0)) != NULL, error = kThreadError_NoBufs);
-
-    header.SetDefaultResponseHeader(aHeader);
-
-    SuccessOrExit(error = message->Append(header.GetBytes(), header.GetLength()));
-
-    SuccessOrExit(error = mCoapServer.SendMessage(*message, messageInfo));
-
-exit:
-
-    if (error != kThreadError_None && message != NULL)
-    {
-        message->Free();
-    }
-
-    return error;
-}
-
 ThreadError NetworkDiagnostic::SendDiagnosticGet(const Ip6::Address &aDestination, const uint8_t aTlvTypes[],
                                                  uint8_t aCount)
 {
@@ -192,8 +167,6 @@ void NetworkDiagnostic::HandleDiagnosticGetAnswer(void *aContext, otCoapHeader *
 void NetworkDiagnostic::HandleDiagnosticGetAnswer(Coap::Header &aHeader, Message &aMessage,
                                                   const Ip6::MessageInfo &aMessageInfo)
 {
-    ThreadError error = kThreadError_None;
-
     VerifyOrExit(aHeader.GetType() == kCoapTypeConfirmable &&
                  aHeader.GetCode() == kCoapRequestPost, ;);
 
@@ -204,7 +177,7 @@ void NetworkDiagnostic::HandleDiagnosticGetAnswer(Coap::Header &aHeader, Message
         mReceiveDiagnosticGetCallback(&aMessage, &aMessageInfo, mReceiveDiagnosticGetCallbackContext);
     }
 
-    SuccessOrExit(error = SendEmptyAck(aHeader, aMessageInfo));
+    SuccessOrExit(mCoapServer.SendEmptyAck(aHeader, aMessageInfo));
 
     otLogInfoNetDiag("Sent diagnostic answer acknowledgment");
 
@@ -471,9 +444,10 @@ void NetworkDiagnostic::HandleDiagnosticGetQuery(Coap::Header &aHeader, Message
     // DIAG_GET.qry may be sent as a confirmable message.
     if (aHeader.GetType() == kCoapTypeConfirmable)
     {
-        SuccessOrExit(error = SendEmptyAck(aHeader, aMessageInfo));
-
-        otLogInfoNetDiag("Sent diagnostic get query acknowledgment");
+        if (mCoapServer.SendEmptyAck(aHeader, aMessageInfo) == kThreadError_None)
+        {
+            otLogInfoNetDiag("Sent diagnostic get query acknowledgment");
+        }
     }
 
     header.Init(kCoapTypeConfirmable, kCoapRequestPost);
@@ -607,8 +581,6 @@ void NetworkDiagnostic::HandleDiagnosticReset(void *aContext, otCoapHeader *aHea
 void NetworkDiagnostic::HandleDiagnosticReset(Coap::Header &aHeader, Message &aMessage,
                                               const Ip6::MessageInfo &aMessageInfo)
 {
-    ThreadError error = kThreadError_None;
-    Message *message = NULL;
     uint16_t offset = 0;
     uint8_t type;
     NetworkDiagnosticTlv networkDiagnosticTlv;
@@ -616,20 +588,20 @@ void NetworkDiagnostic::HandleDiagnosticReset(Coap::Header &aHeader, Message &aM
     otLogInfoNetDiag("Received diagnostic reset request");
 
     VerifyOrExit(aHeader.GetType() == kCoapTypeConfirmable &&
-                 aHeader.GetCode() == kCoapRequestPost, error = kThreadError_Drop);
+                 aHeader.GetCode() == kCoapRequestPost, ;);
 
     VerifyOrExit((aMessage.Read(aMessage.GetOffset(), sizeof(NetworkDiagnosticTlv),
-                                &networkDiagnosticTlv) == sizeof(NetworkDiagnosticTlv)), error = kThreadError_Drop);
+                                &networkDiagnosticTlv) == sizeof(NetworkDiagnosticTlv)), ;);
 
-    VerifyOrExit(networkDiagnosticTlv.GetType() == NetworkDiagnosticTlv::kTypeList, error = kThreadError_Drop);
+    VerifyOrExit(networkDiagnosticTlv.GetType() == NetworkDiagnosticTlv::kTypeList, ;);
 
-    VerifyOrExit((static_cast<TypeListTlv *>(&networkDiagnosticTlv)->IsValid()), error = kThreadError_Drop);
+    VerifyOrExit((static_cast<TypeListTlv *>(&networkDiagnosticTlv)->IsValid()), ;);
 
     offset = aMessage.GetOffset() + sizeof(NetworkDiagnosticTlv);
 
     for (uint8_t i = 0; i < networkDiagnosticTlv.GetLength(); i++)
     {
-        VerifyOrExit(aMessage.Read(offset, sizeof(type), &type) == sizeof(type), error = kThreadError_Drop);
+        VerifyOrExit(aMessage.Read(offset, sizeof(type), &type) == sizeof(type), ;);
 
         switch (type)
         {
@@ -644,16 +616,12 @@ void NetworkDiagnostic::HandleDiagnosticReset(Coap::Header &aHeader, Message &aM
         }
     }
 
-    SuccessOrExit(error = SendEmptyAck(aHeader, aMessageInfo));
+    SuccessOrExit(mCoapServer.SendEmptyAck(aHeader, aMessageInfo));
 
     otLogInfoNetDiag("Sent diagnostic reset acknowledgment");
 
 exit:
-
-    if (error != kThreadError_None && message != NULL)
-    {
-        message->Free();
-    }
+    return;
 }
 
 }  // namespace NetworkDiagnostic
diff --git a/src/core/thread/network_diagnostic.hpp b/src/core/thread/network_diagnostic.hpp
index ee4698813..919e3576a 100644
--- a/src/core/thread/network_diagnostic.hpp
+++ b/src/core/thread/network_diagnostic.hpp
@@ -109,7 +109,6 @@ private:
     ThreadError AppendIPv6AddressList(Message &aMessage);
     ThreadError AppendChildTable(Message &aMessage);
     ThreadError FillRequestedTlvs(Message &aRequest, Message &aResponse, NetworkDiagnosticTlv &aNetworkDiagnosticTlv);
-    ThreadError SendEmptyAck(Coap::Header &aHeader, const Ip6::MessageInfo &aMessageInfo);
 
     static void HandleDiagnosticGetRequest(void *aContext, otCoapHeader *aHeader, otMessage aMessage,
                                            const otMessageInfo *aMessageInfo);
diff --git a/src/core/thread/panid_query_server.cpp b/src/core/thread/panid_query_server.cpp
index 59e4b05e5..7952b4dbd 100644
--- a/src/core/thread/panid_query_server.cpp
+++ b/src/core/thread/panid_query_server.cpp
@@ -69,6 +69,7 @@ void PanIdQueryServer::HandleQuery(Coap::Header &aHeader, Message &aMessage, con
 {
     MeshCoP::PanIdTlv panId;
     MeshCoP::ChannelMask0Tlv channelMask;
+    Ip6::MessageInfo responseInfo(aMessageInfo);
 
     VerifyOrExit(aHeader.GetCode() == kCoapRequestPost, ;);
 
@@ -83,42 +84,13 @@ void PanIdQueryServer::HandleQuery(Coap::Header &aHeader, Message &aMessage, con
     mPanId = panId.GetPanId();
     mTimer.Start(kScanDelay);
 
-    SendQueryResponse(aHeader, aMessageInfo);
-
-exit:
-    return;
-}
-
-ThreadError PanIdQueryServer::SendQueryResponse(const Coap::Header &aRequestHeader,
-                                                const Ip6::MessageInfo &aRequestInfo)
-{
-    ThreadError error = kThreadError_None;
-    Message *message = NULL;
-    Coap::Header responseHeader;
-    Ip6::MessageInfo responseInfo;
-
-    VerifyOrExit(aRequestHeader.GetType() == kCoapTypeConfirmable, ;);
-
-    VerifyOrExit((message = mCoapServer.NewMessage(0)) != NULL, error = kThreadError_NoBufs);
-
-    responseHeader.SetDefaultResponseHeader(aRequestHeader);
-
-    SuccessOrExit(error = message->Append(responseHeader.GetBytes(), responseHeader.GetLength()));
-
-    memcpy(&responseInfo, &aRequestInfo, sizeof(responseInfo));
     memset(&responseInfo.mSockAddr, 0, sizeof(responseInfo.mSockAddr));
-    SuccessOrExit(error = mCoapServer.SendMessage(*message, responseInfo));
+    SuccessOrExit(mCoapServer.SendEmptyAck(aHeader, responseInfo));
 
     otLogInfoMeshCoP("sent panid query response");
 
 exit:
-
-    if (error != kThreadError_None && message != NULL)
-    {
-        message->Free();
-    }
-
-    return error;
+    return;
 }
 
 void PanIdQueryServer::HandleScanResult(void *aContext, Mac::Frame *aFrame)
diff --git a/src/core/thread/panid_query_server.hpp b/src/core/thread/panid_query_server.hpp
index bed352d88..3bfc76ff0 100644
--- a/src/core/thread/panid_query_server.hpp
+++ b/src/core/thread/panid_query_server.hpp
@@ -81,7 +81,6 @@ private:
     static void HandleUdpReceive(void *aContext, otMessage aMessage, const otMessageInfo *aMessageInfo);
 
     ThreadError SendConflict(void);
-    ThreadError SendQueryResponse(const Coap::Header &aRequestHeader, const Ip6::MessageInfo &aRequestMessageInfo);
 
     Ip6::Address mCommissioner;
     uint32_t mChannelMask;