The present invention and its embodiments are made to provide for dynamic hitless resizing in optical transport network without any identification of matching time slots by the Network Management System (NMS) or any control plane signaling including Generalised Multi Protocol Label Switching (GMPLS). An aspect of the invention provides for a method of hitless ODUflex connection resizing in an optical transport network by incrementing or decrementing the ODUflex connection between the nodes, based on an indication command given to a source node for bandwidth increase or decrease, by identifying and matching at least one time slot through Link Connection Resizing (LCR) protocol message exchanges. Another aspect of the invention provides for a method of hitless ODUflex connection resizing in an optical transport network by decrementing the matching time slot used for the incrementing operation, in case of unsuccessful incrementing operation between nodes.