diff --git a/src/core/coap/coap_base.cpp b/src/core/coap/coap_base.cpp
index 7e76f3cb2..aea4e6d9e 100644
--- a/src/core/coap/coap_base.cpp
+++ b/src/core/coap/coap_base.cpp
@@ -86,5 +86,31 @@ void CoapBase::HandleUdpReceive(void *aContext, otMessage *aMessage, const otMes
                                                  *static_cast<const Ip6::MessageInfo *>(aMessageInfo));
 }
 
+ThreadError CoapBase::SendEmptyMessage(Header::Type aType, 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.Init(aType, kCoapCodeEmpty);
+    responseHeader.SetMessageId(aRequestHeader.GetMessageId());
+
+    VerifyOrExit((message = NewMessage(responseHeader)) != NULL, error = kThreadError_NoBufs);
+
+    SuccessOrExit(error = mSender(this, *message, aMessageInfo));
+
+exit:
+
+    if (error != kThreadError_None && message != NULL)
+    {
+        message->Free();
+    }
+
+    return error;
+}
+
 }  // namespace Coap
 }  // namespace Thread
diff --git a/src/core/coap/coap_base.hpp b/src/core/coap/coap_base.hpp
index a91cce02a..85cf813aa 100644
--- a/src/core/coap/coap_base.hpp
+++ b/src/core/coap/coap_base.hpp
@@ -152,6 +152,36 @@ public:
      */
     uint16_t GetPort(void) { return mSocket.GetSockName().mPort; };
 
+    /**
+     * This method sends a CoAP reset message.
+     *
+     * @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 SendReset(Header &aRequestHeader, const Ip6::MessageInfo &aMessageInfo) {
+        return SendEmptyMessage(kCoapTypeReset, aRequestHeader, aMessageInfo);
+    };
+
+    /**
+     * This method sends a CoAP ACK empty message which is used in Separate Response for confirmable requests.
+     *
+     * @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 SendAck(Header &aRequestHeader, const Ip6::MessageInfo &aMessageInfo) {
+        return SendEmptyMessage(kCoapTypeAcknowledgment, aRequestHeader, aMessageInfo);
+    };
+
 protected:
     ThreadError Start(const Ip6::SockAddr &aSockAddr);
     ThreadError Stop(void);
@@ -161,6 +191,22 @@ protected:
     ReceiverFunction mReceiver;
 
 private:
+
+    /**
+     * This method sends a CoAP empty message, i.e. a header-only message with code equals kCoapCodeEmpty.
+     *
+     * @param[in]  aType           The message type
+     * @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 SendEmptyMessage(Header::Type aType, const Header &aRequestHeader,
+                                 const Ip6::MessageInfo &aMessageInfo);
+
     static void HandleUdpReceive(void *aContext, otMessage *aMessage, const otMessageInfo *aMessageInfo);
 };
 
diff --git a/src/core/coap/coap_client.cpp b/src/core/coap/coap_client.cpp
index 6b45567cb..12be70359 100644
--- a/src/core/coap/coap_client.cpp
+++ b/src/core/coap/coap_client.cpp
@@ -229,31 +229,6 @@ exit:
     return error;
 }
 
-void Client::SendEmptyMessage(const Ip6::Address &aAddress, uint16_t aPort, uint16_t aMessageId, Header::Type aType)
-{
-    Header header;
-    Ip6::MessageInfo messageInfo;
-    Message *message;
-    ThreadError error = kThreadError_None;
-
-    header.Init(aType, kCoapCodeEmpty);
-    header.SetMessageId(aMessageId);
-
-    VerifyOrExit((message = NewMessage(header)) != NULL);
-
-    messageInfo.SetPeerAddr(aAddress);
-    messageInfo.SetPeerPort(aPort);
-
-    SuccessOrExit(error = mSender(this, *message, messageInfo));
-
-exit:
-
-    if (error != kThreadError_None && message != NULL)
-    {
-        message->Free();
-    }
-}
-
 void Client::HandleRetransmissionTimer(void *aContext)
 {
     static_cast<Client *>(aContext)->HandleRetransmissionTimer();
@@ -435,13 +410,14 @@ void Client::ProcessReceivedMessage(Message &aMessage, const Ip6::MessageInfo &a
         break;
 
     case kCoapTypeConfirmable:
-    case kCoapTypeNonConfirmable:
-        if (responseHeader.IsConfirmable())
-        {
-            // Send empty ACK if it is a CON message.
-            SendEmptyAck(aMessageInfo.GetPeerAddr(), aMessageInfo.GetPeerPort(), responseHeader.GetMessageId());
-        }
+        // Send empty ACK if it is a CON message.
+        SendAck(responseHeader, aMessageInfo);
 
+        // fall through
+        ;
+
+    case kCoapTypeNonConfirmable:
+        // Separate response.
         FinalizeCoapTransaction(*message, requestMetadata, &responseHeader, &aMessage, &aMessageInfo, kThreadError_None);
 
         break;
@@ -454,7 +430,7 @@ exit:
         if (responseHeader.IsConfirmable() || responseHeader.IsNonConfirmable())
         {
             // Successfully parsed a header but no matching request was found - reject the message by sending reset.
-            SendReset(aMessageInfo.GetPeerAddr(), aMessageInfo.GetPeerPort(), responseHeader.GetMessageId());
+            SendReset(responseHeader, aMessageInfo);
         }
     }
 }
diff --git a/src/core/coap/coap_client.hpp b/src/core/coap/coap_client.hpp
index 41455b427..eff9ee242 100644
--- a/src/core/coap/coap_client.hpp
+++ b/src/core/coap/coap_client.hpp
@@ -241,14 +241,6 @@ private:
                                  Message *aResponse, const Ip6::MessageInfo *aMessageInfo, ThreadError aResult);
 
     ThreadError SendCopy(const Message &aMessage, const Ip6::MessageInfo &aMessageInfo);
-    void SendEmptyMessage(const Ip6::Address &aAddress, uint16_t aPort, uint16_t aMessageId, Header::Type aType);
-    void SendReset(const Ip6::Address &aAddress, uint16_t aPort, uint16_t aMessageId) {
-        SendEmptyMessage(aAddress, aPort, aMessageId, kCoapTypeReset);
-    };
-    void SendEmptyAck(const Ip6::Address &aAddress, uint16_t aPort, uint16_t aMessageId) {
-        SendEmptyMessage(aAddress, aPort, aMessageId, kCoapTypeAcknowledgment);
-    };
-
     static void HandleRetransmissionTimer(void *aContext);
     void HandleRetransmissionTimer(void);