diff --git a/src/buffer.cpp b/src/buffer.cpp
index 90fd49a4..af506903 100755
--- a/src/buffer.cpp
+++ b/src/buffer.cpp
@@ -28,7 +28,7 @@
 #include "buffer.h"
 
 
-/* Implementation *************************************************************/
+/* Network buffer implementation **********************************************/
 void CNetBuf::Init ( const int iNewBlockSize,
                      const int iNewNumBlocks )
 {
@@ -40,9 +40,6 @@ void CNetBuf::Init ( const int iNewBlockSize,
 
     // use the "get" flag to make sure the buffer is cleared
     Clear ( CT_GET );
-
-    // init statistic
-    ErrorRateStatistic.Init ( MAX_STATISTIC_COUNT );
 }
 
 bool CNetBuf::Put ( const CVector<uint8_t>& vecbyData,
@@ -70,9 +67,6 @@ bool CNetBuf::Put ( const CVector<uint8_t>& vecbyData,
     // copy new data in internal buffer (implemented in base class)
     CBufferBase<uint8_t>::Put ( vecbyData, iInSize );
 
-    // update statistic
-    ErrorRateStatistic.Update ( !bPutOK );
-
     return bPutOK;
 }
 
@@ -120,9 +114,6 @@ bool CNetBuf::Get ( CVector<uint8_t>& vecbyData )
     // class)
     CBufferBase<uint8_t>::Get ( vecbyData );
 
-    // update statistic
-    ErrorRateStatistic.Update ( !bGetOK );
-
     return bGetOK;
 }
 
@@ -239,3 +230,38 @@ void CNetBuf::Clear ( const EClearType eClearType )
         }
     }
 }
+
+
+/* Network buffer with statistic calculations implementation ******************/
+void CNetBufWithStats::Init ( const int iNewBlockSize,
+                              const int iNewNumBlocks )
+{
+    // call base class Init
+    CNetBuf::Init ( iNewBlockSize, iNewNumBlocks );
+
+    // init statistic
+    ErrorRateStatistic.Init ( MAX_STATISTIC_COUNT );
+}
+
+bool CNetBufWithStats::Put ( const CVector<uint8_t>& vecbyData,
+                             const int               iInSize )
+{
+    // call base class Put
+    const bool bPutOK = CNetBuf::Put ( vecbyData, iInSize );
+
+    // update statistic
+    ErrorRateStatistic.Update ( !bPutOK );
+
+    return bPutOK;
+}
+
+bool CNetBufWithStats::Get ( CVector<uint8_t>& vecbyData )
+{
+    // call base class Get
+    const bool bGetOK = CNetBuf::Get ( vecbyData );
+
+    // update statistic
+    ErrorRateStatistic.Update ( !bGetOK );
+
+    return bGetOK;
+}
diff --git a/src/buffer.h b/src/buffer.h
index f48a1c87..eb12fee6 100755
--- a/src/buffer.h
+++ b/src/buffer.h
@@ -193,15 +193,10 @@ protected:
     {
         // in this simulation only the buffer pointers and the buffer state
         // is updated, no actual data is transferred
-        if ( iPutPos + iInSize > iMemSize )
+        iPutPos += iInSize;
+        if ( iPutPos >= iMemSize )
         {
-            // data must be written in two steps because of wrap around
-            iPutPos += iInSize - iMemSize - 1;
-        }
-        else
-        {
-            // data can be written in one step
-            iPutPos += iInSize - 1;
+            iPutPos -= iMemSize;
         }
 
         // set buffer state flag
@@ -219,15 +214,10 @@ protected:
     {
         // in this simulation only the buffer pointers and the buffer state
         // is updated, no actual data is transferred
-        if ( iGetPos + iInSize > iMemSize )
+        iGetPos += iInSize;
+        if ( iGetPos >= iMemSize )
         {
-            // data must be read in two steps because of wrap around
-            iGetPos += iInSize - iMemSize - 1;
-        }
-        else
-        {
-            // data can be read in one step
-            iGetPos += iInSize - 1;
+            iGetPos -= iMemSize;
         }
 
         // set buffer state flag
@@ -252,24 +242,36 @@ protected:
 class CNetBuf : public CBufferBase<uint8_t>
 {
 public:
-    void Init ( const int iNewBlockSize, const int iNewNumBlocks );
+    virtual void Init ( const int iNewBlockSize, const int iNewNumBlocks );
     int GetSize() { return iMemSize / iBlockSize; }
 
-    bool Put ( const CVector<uint8_t>& vecbyData, const int iInSize );
-    bool Get ( CVector<uint8_t>& vecbyData );
-
-    double GetErrorRate() { return ErrorRateStatistic.GetAverage(); }
+    virtual bool Put ( const CVector<uint8_t>& vecbyData, const int iInSize );
+    virtual bool Get ( CVector<uint8_t>& vecbyData );
 
 protected:
     enum EClearType { CT_PUT, CT_GET };
 
     void Clear ( const EClearType eClearType );
 
-    int              iBlockSize;
-    int              iNumInvalidElements;
+    int iBlockSize;
+    int iNumInvalidElements;
+};
 
+
+// Network buffer (jitter buffer) with statistic calculations ------------------
+class CNetBufWithStats : public CNetBuf
+{
+public:
+    virtual void Init ( const int iNewBlockSize, const int iNewNumBlocks );
+
+    virtual bool Put ( const CVector<uint8_t>& vecbyData, const int iInSize );
+    virtual bool Get ( CVector<uint8_t>& vecbyData );
+
+    double GetErrorRate() { return ErrorRateStatistic.GetAverage(); }
+
+protected:
     // statistic
-    CErrorRate       ErrorRateStatistic;
+    CErrorRate ErrorRateStatistic;
 };
 
 
diff --git a/src/channel.h b/src/channel.h
index 09badca5..e0123c36 100755
--- a/src/channel.h
+++ b/src/channel.h
@@ -143,7 +143,7 @@ protected:
     CVector<double>     vecdGains;
 
     // network jitter-buffer
-    CNetBuf             SockBuf;
+    CNetBufWithStats    SockBuf;
     int                 iCurSockBufNumFrames;
 
     CCycleTimeVariance  CycleTimeVariance;