International Journal of Engineering Trends and Technology (IJETT) – Volume 18 Number2- Dec 2014 ISSN: 2231-5381 http://www.ijcttjournal.org Page 64 Implementation of Data Link Control Protocols in Wired Network Sudhanshu Maurya #1 , Vikas Kumar Nayak *2 , Dr. A Nagaraju #3 # Assistant Professsor, Department of Computer Science & Engineering, Jharkhand Rai University Ranchi, Jharkhand, India Abstract— Data Link Layer is the protocol layer which transfers data between connected networks. It provides the functional and procedural means to transfer data between network and its nodes. It also provide the means to rectify the errors and usually correct it that may occur in the Physical Layer. Study and simulate protocol to analyse and find the advantages and disadvantages to improve the quality of protocol such that it handles the network data transmission in proper way. The protocol is studied so that the details of the protocols are revealed and the limitations of the protocol can be overcome later. In this research paper we give a brief introduction about Data Link Layer Protocols and introduced a new protocol (Protocol 7) to overcome the problem of previous protocols on the basis of priority of the frame. Keywords— Protocol, Adjacent network, Simulate, Transmission, Segment, Frame. I. INTRODUCTION When we communicate with someone, we are sharing our information. It is exchange of data between two devices via some form of transmission medium such as a wired cable. The data communication system consists of five components i.e. Sender, Receiver, Message, Transmission medium and Protocol. Sender sends the message to other nodes of the network. Receiver receives the message from sender. Message is data that is to be communicated. Transmission medium is a path by which message travels from one node to another. Protocol is a set of rules that helps to control data communication between communication devices [1]. OSI (Open System Interconnection) model is commonly used to specify and describe computer communication protocol [2]. It was first taken into consideration in late 1970s. The motive of the OSI model is to show how to facilitate communication between different systems. It is not a protocol; it is a model for designing and understanding network architecture. The second layer of OSI model is Data Link Layer it handles a system which have two nodes connected via a physical link. The major work of this layer is to establish a connection between the nodes of network, one for sending and other for receiving. Data Link Layer has two sub layers: Data Link Control and Media Access Control. The data link layer is responsible for designing and communication between two contiguous nodes. II. PROTOCOLS OF DATA LINK CONTROL PROTOCOL Data Link Control Protocol consists of six protocols, two for noiseless channel i.e. ideal channel and four for noisy channel i.e. real channel. The first category of protocols is not actually implemented because ideal channel does not exist in present scenario. The list of protocols is: Unrestricted Simplex Protocol, Stop and Wait, Positive Acknowledgment with Retransmission, Sliding Window Protocols, Go-Back-N, and Selective Repeat [10]. A. Unrestricted Simplex Protocol It is a simple protocol with no restrictions. It has no error control and flow control. This protocol provides data transmission in only one direction only i.e from sender to receiver. We assume that the communication channel is to be error free and the receiver is able to process all the input infinitely quickly. The sender pumps the data as fast as it can. The problem with this protocol is it assumes an error free communication channel [3]. So there is no provision of detection and correction of errors in data frame. B. Stop and Wait In Stop and Wait protocol the sender takes packets from network layer. Copies the packet into frames and transmit them. After this the sender busy waits for an ACK from receiver side. The receiver is busy and waits until a frame is not received from sender side. When frame is received it passes the data packet to network layer and sends an ACK to the sender for the frame is successfully received. Then it back to waiting stage and this process is continues till end of file. Here only one outstanding frame at a time so no sequence number is required. In this protocol it is easy to see the frame, ACK lost / damage or a deadlock situation. The main problem with this protocol is if the ACK not received by the sender then it wait for infinite time[16]. C. Possative Acknowledgement with Retransmission Possative Acknowledgement with Retransmission (PAR) protocol is updated version of Stop and Wait Protocol. It is a Stop and Wait Protocol with ARQ (Automatic Repeat Request). ARQ protocols are mainly used in communication system for their easy implementation and good reliability [5][13]. In this protocol there is only one outstanding frame at a time so sequence number used to determine any lost or damaged frame and sequence number does not respond until a positive acknowledgement is not received. Here only ‘0’ and ‘1’ is used as a sequence number. It can’t change to other sequence number until the correct one is received. The ACK frame sent back is marked as an ACK frame as it contains the