Update README and add contrib dir

contrib/tsn/model/frer-sequence-encode-decode-function.h

@@ -0,0 +1,56 @@
+#ifndef FRER_SEQUENCE_ENCODE_DECODE_FUNCTION_H
+#define FRER_SEQUENCE_ENCODE_DECODE_FUNCTION_H
+
+#include "ns3/object.h"
+
+#include "ns3/packet.h"
+
+#include "tsn-net-device.h"
+
+namespace ns3
+{
+class TsnNetDevice;
+
+class SequenceEncodeDecodeFunction : public Object
+{
+  public:
+    /**
+     * \brief Get the TypeId
+     *
+     * \return The TypeId for this class
+     */
+    static TypeId GetTypeId();
+
+    /**
+     * \brief Create a SequenceEncodeDecodeFunction
+     */
+    SequenceEncodeDecodeFunction();
+
+    /**
+     * Destroy a SequenceEncodeDecodeFunction
+     *
+     * This is the destructor for the SequenceEncodeDecodeFunction.
+     */
+    ~SequenceEncodeDecodeFunction();
+
+    void SetStreamHandle(std::vector<uint32_t> seqEncStreamList);
+    void SetPort(Ptr<TsnNetDevice> seqEncPort);
+
+    bool IsApplicable(uint32_t streamHandle, Ptr<TsnNetDevice> port, bool direction);
+
+    void Encode(Ptr<Packet> p, uint16_t seqNumber);
+    uint16_t Decode(Ptr<Packet> p);
+
+  protected:
+
+
+  private:
+    std::vector<uint32_t> m_frerSeqEncStreamList;
+    Ptr<TsnNetDevice> m_frerSeqEncPort;
+    bool m_frerSeqEncDirection;
+    bool m_frerSeqEncActive;
+    uint8_t m_frerSeqEncEncapsType = 1; //RTAG encoding (802.1CB-2017 section 10.5.1.5)
+};
+
+}
+#endif /* FRER_SEQUENCE_ENCODE_DECODE_FUNCTION_H */