 Hello everyone. Myself, Mr. Sioppa, I am Madhga. I am working as an assistant professor in computer science and engineering department at Vulture Institute of Technology, Solapur. Now I welcome to the session on TCP IP reference model. In the last videos, we have discussed about the users of computer network, network software, network hardware and vice-reference model. Let's see the learning outcomes. At the end of this session, students will be able to describe the concept of TCP IP reference model, functions of each layers. And they are also able to compare the vice-reference model TCP IP model about TCP IP reference model, host to network layer, internet layer, transport layer, application layer. These are the topics I am going to cover in this video. So, TCP IP reference model, the set of communication protocols used for the internet and other similar network. Here the TCP, this layer is an vice-reference model, this is a TCP IP reference model. This TCP IP, a vice-reference model can contain seven layers that are physical layer, data link layer, network layer, transport layer, session layer, presentation layer and application layer. And TCP IP reference model can contains the only four layers that are host to network layer. This layer we can also call it is a network access layer, an interface layer or network layer. The second one is the internet layer, transport layer and then application layer. Here as compared to vice-reference model, some layers are combined togetherly. They have called only one layer in TCP IP reference model. Under those it means the data link layer and physical layer of vice-reference model combined togetherly they have called only one layer in TCP IP that is host to network layer or network interface layer. And then network layer we can call it is an internet layer, transport layer and then three layers of vice-reference model that are session layer, presentation layer, application layer, they have combined togetherly only one layer in TCP IP that is application layer. Session layer and presentation layer is not present in TCP IP reference model. Why they have combined those layers in TCP IP? It means functioning and working of those layers is common in TCP IP reference model. This figure is a layers of TCP IP reference model, TCP IP is a family of protocols, a few protocols wide, low level, functions needed for many applications. These includes IP, TCP and UDP. These are the four layers are there in a vice-reference or sorry TCP IP reference model and then what are the different protocols can belongs to each layers. First one is network interface or host to network layer that it can contains an Ethernet, token ring and other link layer protocols. Network layer can contains four protocols that are IP, internet protocol, ERP, ICMP and IGMP. The transport layer can contains TCP protocol and UDP protocol. The application layer can contains HTTP, FTP, Telnet, SMTP and DNS. Then some other protocols are also there in each and every layers. That protocols can be used for different purpose. First layer is host to network layer. The physical and data link layer can combine togetherly, host to network layer or network interface layer. Most companies have a substantial number of computers that computers can be used for sharing the resources, sharing the information, saving the time, saving the money also. This is the lowest layer of the vice-reference model as well as TCP IP reference model. The protocol is used to connect the host so that packet can send over it varies from host to host and network to network. In the next layer that is internet layer, the internet layer can contains some protocols that can be used for different purpose. It is the layer which holds the whole architecture together. It means the architecture can contains the number of layers that number of protocols that protocols can be used and those layers can interface with each other before transmitting the data from upper layer to the lower layer. It helps the packet to travel independently to the destination. In the internet layer, the packets can travel independently to the destination. Order in which packets are issued is different from the way they are sent. IP that is internet protocol is used in this layer for transmitting the packets or data. Next one is internet layer, the various functions performed by the internet layer that are delivering of IP packets, performing routing, avoiding congestion, delivering a packet means odd. It means before transmitting any data from the source to the destination in the source side the user should have to mention the destination information based on that only the user can transfer the data then that data will deliver to the destination independently in the internet layer. Performing routing it means through routers we have to transfer the packets. Performing congestion means the sending speed is very high, receiver speed is very slow then that time the user may face a problem of congestion it means storing problem. Then if you are maintaining the sending side speed and receiving side speed is common then we can avoid the congestion. Next one is transport layer, transport layer is the, in the transport layer the user can send some data by using some protocol that is the TCP and UDP protocol. The functions of this transport layer is such as multiplexing, segmenting and splitting on the data is done by transport layer. It means in the user is facing the problem of transmitting it means they can split the data then they can transfer to the next user. The applications can read and write to the transport layer. Transport layer adds header information to the data it means before transmitting both upper layer as well as current layer they can interface with each other. After interfacing the data can pass to the next layer the next layer can adds its header own header information to the current layer then it can pass it to the next that is by this is the concept of transport layer. In transport layer only we have to add the data to the information to the data. It breaks the message into small units so that they are handled more efficiently by the network layer. Transport layer also arrange the packets to be sent in sequence it means whatever the sequence is there in the sender side the same sequence we have to get in the receiver side. The transport layer it is in connection TCP protocol and UDP protocol we have to use the TCP protocol is in connection oriented protocol then whatever the data we are transmitting using TCP protocol the same data we have to receive in the receiver side also. Transporting layer it contains all higher level protocols such as Telnet, FTP, SMTP, DNS and summer protocols. What is Telnet? It is a two-way communication protocol which allows connecting to remote machines and run applications on it. Next FTP, FTP is a file transfer protocol it allows file transfer among among its computers users connected over network it is reliable simple and efficient. SMTP, simple mail transfer protocol it is used to transport electronic mail between source and destination are directed via RUV DNS domain name system it resolves an IP address into a textual addresses for host and connected over network. Next one is the reflection spot it can contain one question that is list some merits and demerits of TCP IP model. Now pause the video and answer the question. The answer for the above question is merits are it operates independently it is scalable client server architecture supports a number of routing protocols and it can be used to establish a connection between two computers demerits are transport layer does not guarantee delivery of packets the model cannot be used in any other applications replacing protocol is not easy it has not clearly separated its services interface sign protocols. Now a comparison of WESA reference model and TCP IP reference model the WESA model makes a clear distinction between services interface sign protocols each layer performs some services for the layer above it the WESA model has seven layers while the TCP IP model has five layers or four layers both how network and transport application layers but the other layers are different WESA model supports both connectionless and connection oriented communication TCP IP supports only connectionless communication these are the references I use for preparing the above PPT. Thank you.