diff --git a/protocol/esta/acn/pdu.h b/protocol/esta/acn/pdu.h
index 0503a18..7ef0774 100644
--- a/protocol/esta/acn/pdu.h
+++ b/protocol/esta/acn/pdu.h
@@ -42,6 +42,7 @@ namespace ACN::PDU {
 
 class Pdu; // forward declare
 
+
 /**
  * @brief The pdu_header struct
  */
@@ -85,12 +86,12 @@ struct Block
   /**
    * @brief member Messages of this block
    */
-  std::vector<Message<T>> pdu;
+  std::vector<std::shared_ptr<T>> pdu;
   /**
    * @brief setParent
    * @param parent
    */
-  void setParent(Message<Pdu> parent) {
+  void setParent(std::shared_ptr<Pdu> parent) {
     for (auto &p : pdu)
       p->setParent(parent);
   }
@@ -163,7 +164,7 @@ public:
   uint32_t        vector(); // may inherit
   std::shared_ptr<pdu_header> header(); // may inherit
   std::shared_ptr<pdu_data>   data();   // may inherit
-  Message<Pdu>    parent();
+  std::shared_ptr<Pdu>        parent();
   Stream          stream();
   virtual size_t  streamSize() const override;
   virtual void    iStream(Stream) override;
@@ -173,8 +174,8 @@ public:
   void setVector (const uint32_t);
   void setHeader (std::shared_ptr<pdu_header>);
   void setData   (std::shared_ptr<pdu_data>);
-  void setParent (Message<Pdu> pdu);
-  void setInherit(Message<Pdu> pdu);
+  void setParent (std::shared_ptr<Pdu> pdu);
+  void setInherit(std::shared_ptr<Pdu> pdu);
 
   // protocol payloads
   /**
@@ -220,12 +221,12 @@ public:
   }
 
 protected:
-  pdu_flags    flags_;            //!< flags for length, vector, header and data
-  uint32_t     vector_ = 0;       //!< vector of this PDU
-  size_t       vector_size_;      //!< width (numbe of octets) of the vector
-  Message<Pdu> parent_;           //!< parent PDU
-  Message<Pdu> inherit_;          //!< PDU from which to inherit
-  Stream       stream_;           //!< buffer
+  pdu_flags    flags_;                      //!< flags for length, vector, header and data
+  uint32_t     vector_ = 0;                 //!< vector of this PDU
+  size_t       vector_size_;                //!< width (numbe of octets) of the vector
+  std::shared_ptr<Pdu> parent_;             //!< parent PDU
+  std::shared_ptr<Pdu> inherit_;            //!< PDU from which to inherit
+  std::shared_ptr<bufferstream> stream_;    //!< buffer
   std::shared_ptr<pdu_header> header_ = nullptr; //!< header segment
   std::shared_ptr<pdu_data>   data_   = nullptr; //!< data segment
 };