Added doc comment
diff --git a/ndn-cpp/transport/Transport.hpp b/ndn-cpp/transport/Transport.hpp
index 94e60ec..70f7dbc 100644
--- a/ndn-cpp/transport/Transport.hpp
+++ b/ndn-cpp/transport/Transport.hpp
@@ -11,6 +11,10 @@
 class NDN;  
 class Transport {
 public:
+  /**
+   * 
+   * @param ndn Not a shared_ptr because we assume that it will remain valid during the life of this Transport object.
+   */
   virtual void connect(NDN &ndn);
   
   virtual void send(unsigned char *data, unsigned int dataLength);