To successfully transmit data over any network, a protocol is required to manage the flow or space at which the data is transmitted. High-level Data Link Control (HDLC) is a group of protocols for transmitting synchronous data packets between point-to-point nodes. In HDLC, data is organized into a frame. It resides on layer 2 of the open system interconnect model, i.e. data link layer. HDLC uses zero insertion/deletion process called bit stuffing to ensure that the bit pattern of the delimiter flag does not occur in the fields between flags.