Introduction to Data Communication and Networking

VI SEM EEE

EEE- 324T

Department of Electrical and Electronics Engineering, BVCOE, New Delhi

Subject: IDCN, Instructor: Dr.SUDHA.K

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�COURSE OBJECTIVES

• 1. To build an understanding of the fundamental concepts of data communication.
• 2. To familiarize the student with the basic taxonomy of data link layer.
• 3. To understand and implement the network routing, IP addressing, subnetting.
• 4. To enumerate the functions of transport layer and application layer.

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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COURSE OUTCOMES(CO)

CO 1 Understand basic concepts of data communications.

CO 2 Understand and explain various functions of data link layer.

CO 3 Understand and implements the network routing, IP addressing, subnetting.

CO 4 Enumerate the functions of transport layer and application layer.

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

�UNIT- III

• Network Layer: Design issues, Routing algorithms.
• Congestion control algorithms.
• Host to Host Delivery: Internetworking, addressing and routing.
• IP addressing, Subnet.
• Network Layer Protocols: ARP, IPV4, ICMP, IPV6 ad ICMPV6.

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

����������Network Layer-Design Issues�

• The network layer in the TCP/IP protocol suite is responsible for the host-to host delivery of datagrams.
• It provides services to the transport layer and receives services from the datalink layer.
• The network layer translates the logical addresses into physical addresses.
• It determines the route from the source to the destination and also manages the traffic problems such as switching, routing and controls the congestion of data packets.
• The main role of the network layer is to move the packets from sending host to the receiving host.

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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Network layer is majorly focused on getting packets from the source to the destination, routing error handling and congestion control.

various functions of network layer:

Addressing:�Maintains the address at the frame header of both source and destination and performs addressing to detect various devices in network.

Packeting:�This is performed by Internet Protocol. The network layer converts the packets from its upper layer.

Routing:�It is the most important functionality. The network layer chooses the most relevant and best path for the data transmission from source to destination.

Inter-networking:�It works to deliver a logical connection across multiple devices.

• Network layer design issues:
• 1. Store and Forward packet switching:
• The host sends the packet to the nearest router.
• This packet is stored there until it has fully arrived once the link is fully processed by verifying the checksum then it is forwarded to the next router till it reaches the destination.
• This mechanism is called “Store and Forward packet switching.”

Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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• 2. Services provided to Transport Layer:�Through the network/transport layer interface, the network layer transfers it’s services to the transport layer.
• These services are described below.�But before providing these services to the transfer layer following goals must be kept in mind :-
• Offering services must not depend on router technology.
• The transport layer needs to be protected from the type, number and topology of the available router.
• The network addresses for the transport layer should use uniform numbering pattern also at LAN and WAN connections.

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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• Based on the connections there are 2 types of services provided :
• Connectionless – The routing and insertion of packets into subnet is done individually. No added setup is required.
• Connection-Oriented – Subnet must offer reliable service and all the packets must be transmitted over a single route.

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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• 3. Implementation of Connectionless Service:�Packet are termed as “datagrams” and corresponding subnet as “datagram subnets”.
• When the message size that has to be transmitted is 4 times the size of the packet, then the network layer divides into 4 packets and transmits each packet to router via. a few protocol.
• Each data packet has destination address and is routed independently irrespective of the packets.

Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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• 4. Implementation of Connection Oriented service:�To use a connection-oriented service, first we establishes a connection, use it and then release it.
• In connection-oriented services, the data packets are delivered to the receiver in the same order in which they have been sent by the sender.

Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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• Circuit Switched Connection – A dedicated physical path or a circuit is established between the communicating nodes and then data stream is transferred.
• Virtual Circuit Switched Connection – The data stream is transferred over a packet switched network, in such a way that it seems to the user that there is a dedicated path from the sender to the receiver. A virtual path is established here. While, other connections may also be using the same path.

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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Routing algorithm�

• In order to transfer the packets from source to the destination, the network layer must determine the best route through which packets can be transmitted.
• Whether the network layer provides datagram service or virtual circuit service, the main job of the network layer is to provide the best route. The routing protocol provides this job.
• The routing protocol is a routing algorithm that provides the best path from the source to the destination. The best path is the path that has the "least-cost path" from source to the destination.
• Routing is the process of forwarding the packets from source to the destination but the best route to send the packets is determined by the routing algorithm.

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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Classification of a Routing algorithm�

• The Routing algorithm is divided into two categories:
• Adaptive Routing algorithm
• Non-adaptive Routing algorithm

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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Adaptive Routing algorithm�

• An adaptive routing algorithm is also known as dynamic routing algorithm.
• This algorithm makes the routing decisions based on the topology and network traffic.
• The main parameters related to this algorithm are hop count, distance and estimated transit time.

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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• An adaptive routing algorithm can be classified into three parts:
• Centralized algorithm: It is also known as global routing algorithm as it computes the least-cost path between source and destination by using complete and global knowledge about the network.
• This algorithm takes the connectivity between the nodes and link cost as input, and this information is obtained before actually performing any calculation. Link state algorithm is referred to as a centralized algorithm since it is aware of the cost of each link in the network.
• Isolation algorithm: It is an algorithm that obtains the routing information by using local information rather than gathering information from other nodes.

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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• Distributed algorithm: 
• It is also known as decentralized algorithm as it computes the least-cost path between source and destination in an iterative and distributed manner.
• In the decentralized algorithm, no node has the knowledge about the cost of all the network links.
• In the beginning, a node contains the information only about its own directly attached links and through an iterative process of calculation computes the least-cost path to the destination.
• A Distance vector algorithm is a decentralized algorithm as it never knows the complete path from source to the destination, instead it knows the direction through which the packet is to be forwarded along with the least cost path.

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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Non-Adaptive Routing algorithm�

• Non Adaptive routing algorithm is also known as a static routing algorithm.
• When booting up the network, the routing information stores to the routers.
• Non Adaptive routing algorithms do not take the routing decision based on the network topology or network traffic.

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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• The Non-Adaptive Routing algorithm is of two types:
• Flooding: In case of flooding, every incoming packet is sent to all the outgoing links except the one from it has been reached. The disadvantage of flooding is that node may contain several copies of a particular packet.
• Random walks: In case of random walks, a packet sent by the node to one of its neighbors randomly. An advantage of using random walks is that it uses the alternative routes very efficiently.

Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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Congestion control algorithms

• What is congestion?
• A state occurring in network layer when the message traffic is so heavy that it slows down network response time.
• Effects of Congestion:
• As delay increases, performance decreases.
• If delay increases, retransmission occurs, making situation worse.

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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• Congestion Control is a mechanism that controls the entry of data packets into the network, enabling a better use of a shared network infrastructure and avoiding congestive collapse. 
• Congestive-Avoidance Algorithms (CAA) are implemented at the TCP layer as the mechanism to avoid congestive collapse in a network.

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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Leaky Bucket Algorithm�

• The leaky bucket algorithm discovers its use in the context of network traffic shaping or rate-limiting. 
• A leaky bucket execution and a token bucket execution are predominantly used for traffic shaping algorithms.
• This algorithm is used to control the rate at which traffic is sent to the network and shape the burst traffic to a steady traffic stream.
• The disadvantages compared with the leaky-bucket algorithm are the inefficient use of available network resources.
• The large area of network resources such as bandwidth is not being used effectively.� 

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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• Imagine a bucket with a small hole in the bottom.
• No matter at what rate water enters the bucket, the outflow is at constant rate.
• When the bucket is full with water additional water entering spills over the sides and is lost.

Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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• Similarly, each network interface contains a leaky bucket and the following steps are involved in leaky bucket algorithm:
•  When host wants to send packet, packet is thrown into the bucket.
•  The bucket leaks at a constant rate, meaning the network interface transmits packets at a constant rate.
•  Bursty traffic is converted to a uniform traffic by the leaky bucket.
• In practice the bucket is a finite queue that outputs at a finite rate.

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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Token bucket Algorithm�

• The leaky bucket algorithm has a rigid output design at an average rate independent of the bursty traffic.
• In some applications, when large bursts arrive, the output is allowed to speed up. This calls for a more flexible algorithm, preferably one that never loses information. Therefore, a token bucket algorithm finds its uses in network traffic shaping or rate-limiting.
• It is a control algorithm that indicates when traffic should be sent. This order comes based on the display of tokens in the bucket. 
• The bucket contains tokens. Each of the tokens defines a packet of predetermined size. Tokens in the bucket are deleted for the ability to share a packet.
• When tokens are shown, a flow to transmit traffic appears in the display of tokens.
•  No token means no flow sends its packets. Hence, a flow transfers traffic up to its peak burst rate in good tokens in the bucket.

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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• Need of token bucket Algorithm:-
• The leaky bucket algorithm enforces output pattern at the average rate, no matter how bursty the traffic is.
• So in order to deal with the bursty traffic we need a flexible algorithm so that the data is not lost. One such algorithm is token bucket algorithm.

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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• Steps of this algorithm can be described as follows:
• In regular intervals tokens are thrown into the bucket. ƒ
• The bucket has a maximum capacity. ƒ
• If there is a ready packet, a token is removed from the bucket, and the packet is sent.
• If there is no token in the bucket, the packet cannot be sent.

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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In figure (A) we see a bucket holding three tokens, with five packets waiting to be transmitted. For a packet to be transmitted, it must capture and destroy one token. In figure (B) We see that three of the five packets have gotten through, but the other two are stuck waiting for more tokens to be generated.

• Ways in which token bucket is superior to leaky bucket:
• The leaky bucket algorithm controls the rate at which the packets are introduced in the network, but it is very conservative in nature.
• Some flexibility is introduced in the token bucket algorithm. In the token bucket, algorithm tokens are generated at each tick (up to a certain limit).
• For an incoming packet to be transmitted, it must capture a token and the transmission takes place at the same rate.
• Hence some of the busty packets are transmitted at the same rate if tokens are available and thus introduces some amount of flexibility in the system.

Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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• Formula: M * s = C + ? * s where S – is time taken M – Maximum output rate ? – Token arrival rate C – Capacity of the token bucket in byte

Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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Host to Host delivery

Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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• Network Layer Duties

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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• Network Layer is responsible for the transmission of data or communication from one host to another host connected in a network.
• Rather than describing how data is transferred, it implements the technique for efficient transmission.
• In order to provide efficient communication protocols are used at the network layer.
• The data is being grouped into packets or in the case of extremely large data it is divided into smaller sub packets. Each protocol used has specific features and advantages.
• The below article covers in detail the protocols used at the network layer.

Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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Network Layer Protocols

• Logical Addressing: Each device on the network needs to be identified uniquely. Therefore network layer provides an addressing scheme to identify the device. It places the IP address of every sender and the receiver in the header. This header consists of the network ID and host ID of the network.
• Host-to-host Delivery of Data: The network layer ensures that the packet is being delivered successfully from the sender to the receiver. This layer makes sure that the packet reaches the intended recipient only.
• Fragmentation: In order to transmit the larger data from sender to receiver, the network layer fragments it into smaller packets. Fragmentation is required because every node has its own fixed capacity for receiving data.

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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Functions of Network Layer

• Congestion Control: Congestion is defined as a situation where the router is not able to route the packets property which results in aggregation of packets in the network. Congestion occurs when a large amount of packets are flooded in the network. Therefore network layer controls the congestion of data packets in the network.
• Routing and Forwarding: Routing is the process that decides the route for transmission of packets from sender to receiver. It mostly chooses the shortest path between the sender and the receiver. Routing protocols that are mostly used are path vector, distance vector routing, link state routing, etc.

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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• Network Layer Protocols

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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• 1. IP (Internet Protocol)
• IP stands for Internet Protocol. Internet Protocol helps to uniquely identify each device on the network.
• Internet protocol is responsible for transferring the data from one node to another node in the network.
• Internet protocol is a connectionless protocol therefore it does not guarantee the delivery of data.
• For the successful delivery higher level protocols such as TCP are used to guarantee the data transmission. The Internet Protocol is divided in two types. They are:

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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• IPv4: IPv4 provides with the 32 bit address scheme. IPv4 addressing has four numeric fields and are separated by dot.
• IPv4 can be configured either using DHCP or manually.
• IPv4 does not provide with more security features as it does not support authentication or encryption techniques.
• IPv4 is further divided into five classes as Class A, Class B, Class C, Class D and Class E.
• IPv6: IPv6 is the most recent version of IP.
• If provided with a 128 but addressing scheme. IP address has eight fields that are separated by colon, and these fields are alphanumeric. The IPv6 address is represented in hexadecimal.
• IPv6 provides with more security features such as authentication and encryption. IPv6 supports end-to-end connection integrity. IPv6 provides with more range of IP address as compared to IPv4. 

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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• 2. ARP (Address Resolution Protocol)
• ARP stands for Address Resolution Protocol. ARP is used to convert the logical address ie. IP address into physical address ie. MAC address.
• While communicating with other nodes, it is necessary to know the MAC address or physical address of the destination node.
• If any of the node in a network wants to know the physical address of another node in the same network, the host then sends an ARP query packet.
• This ARP query packet consists of IP address and MAC address of source host and only the IP address of destination host. This ARP packet is then received to every node present in the network.
• The node with its own IP address recognises it and sends it MAC address to the requesting node. But sending and receiving such packets to know the MAC address of destination node it increases the traffic load.
• Therefore in order to reduce this traffic and improve the performance, the systems that makes use of ARP maintain a cache of recently acquired IP into MAC address bindings.

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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• How Does ARP Work?
• The host broadcasts an ARP inquiry packet containing the IP address over the network in order to find out the physical address of another computer on its network.
• The ARP packet is received and processed by all hosts on the network; however, only the intended recipient can identify the IP address and reply with the physical address.
• After adding the physical address to the datagram header and cache memory, the host storing the datagram transmits it back to the sender.

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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• 3. RARP
• RARP stands for Reverse Address Resolution Protocol. RARP works opposite of ARP. Reverse Address Resolution Protocol is used to convert MAC address ie. physical address into IP address ie. logical address.
• RARP provides with a feature for the systems and applications to get their own IP address from a DNS( Domain Name System) or router. This type of resolution is required for various tasks such as executing reverse DNS lookup.
• As Reverse Address Resolution Protocol works at low level it requires direct network addresses. The reply from the server mostly carries a small information but the 32 bit internet address is used and it does not exploit the full potential of a network such as ethernet.

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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• How Does RARP Work?
• Data is sent between two places in a network using the RARP, which is on the Network Access Layer.
• Every user on the network has two distinct addresses: their MAC (physical) address and their IP (logical) address.
• Software assigns the IP address, and the hardware then builds the MAC address into the device.
• Any regular computer connected to the network can function as the RARP server, answering to RARP queries. It must, however, store all of the MAC addresses’ associated IP addresses. Only these RARP servers are able to respond to RARP requests that are received by the network. The information package must be transmitted over the network’s lowest tiers.
• Using both its physical address and Ethernet broadcast address, the client transmits a RARP request. In response, the server gives the client its IP address.
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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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Difference between ARP and RARP

• 4. ICMP
• ICMP stands for Internet Control Message Protocol. ICMP is a part of IP protocol suite. ICMP is an error reporting and network diagnostic protocol. Feedback in the network is reported to the designated host. Meanwhile, if any kind of error occur it is then reported to ICMP. ICMP protocol consists of many error reporting and diagnostic messages. ICMP protocol handles various kinds of errors such as time exceeded, redirection, source quench, destination unreachable, parameter problems etc. The messages in ICMP are divided into two types. They are given below:
• Error Message: Error message states about the issues or problems that are faced by the host or routers during processing of IP packet.
• Query Message: Query messages are used by the host in order to get information from a router or another host.

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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• How Does ICMP Work?
• The main and most significant protocol in the IP suite is called ICMP. However, unlike TCP and UDP, ICMP is a connectionless protocol, meaning it doesn’t require a connection to be established with the target device in order to transmit a message.
• TCP and ICMP operate differently from one another; TCP is a connection-oriented protocol, while ICMP operates without a connection. Every time a connection is made prior to a message being sent, a TCP Handshake is required of both devices.
• Datagrams including an IP header containing ICMP data are used to transmit ICMP packets. An independent data item like a packet is comparable to an ICMP datagram.

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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• 5. IGMP
• IGMP stands for Internet Group Message Protocol.
• ICMP is a multicasting communication protocol. It utilizes the resources efficiently while broadcasting the messages and data packets. ICMP is also a protocol used by TCP/IP.
• Other hosts connected in the network and routers makes use of ICMP for multicasting communication that have IP networks. In many networks multicast routers are used in order to transmit the messages to all the nodes. Multicast routers therefore receives large number of packets that needs to be sent.
• But to broadcast this packets is difficult as it would increase the overall network load. Therefore ICMP helps the multicast routers by addressing them while broadcasting.
• As multicast communication consists of more than one senders and receivers the Internet Group Message Protocol is majorly used in various applications such as streaming media, web conference tools, games, etc.

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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• How Does IGMP Work?
• Devices that can support dynamic multicasting and multicast groups can use IGMP.
• The host has the ability to join or exit the multicast group using these devices. It is also possible to add and remove customers from the group using these devices.
• The host and local multicast router use this communication protocol. Upon creation of a multicast group, the packet’s destination IP address is changed to the multicast group address, which falls inside the class D IP address range.

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Department of Electrical and Electronics Engineering, BVCOE New Delhi Subject: IDCN, Instructor: Dr.SUDHA.K

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