+ * ID of the connection.
+ */
+ struct GNUNET_CADET_ConnectionTunnelIdentifier cid;
+
+};
+
+
+/**
+ * Message to acknowledge cadet encrypted traffic, used for
+ * flow-control on a hop-by-hop basis on the connection-level. Note
+ * that we do use the @e cemi from the tunnel layer as the connection
+ * layer's header is included/shared with the tunnel layer messages,
+ * and we only do flow control for the payload.
+ */
+struct GNUNET_CADET_ConnectionEncryptedAckMessage
+{
+ /**
+ * Type: #GNUNET_MESSAGE_TYPE_CADET_CONNECTION_HOP_BY_HOP_ENCRYPTED_ACK
+ */
+ struct GNUNET_MessageHeader header;
+
+ /**
+ * Maximum packet ID authorized.
+ */
+ struct CadetEncryptedMessageIdentifier cemi_max;
+
+ /**
+ * ID of the connection.
+ */
+ struct GNUNET_CADET_ConnectionTunnelIdentifier cid;
+};
+
+#endif
+
+
+/******************************************************************************/
+/******************************* CHANNEL ***********************************/
+/******************************************************************************/
+
+
+/**
+ * Message to create a Channel.
+ */
+struct GNUNET_CADET_ChannelOpenMessage
+{
+ /**
+ * Type: #GNUNET_MESSAGE_TYPE_CADET_CHANNEL_OPEN