Found 1320 Articles for MCA

The application layer is the highest abstraction layer of the TCP/IP model that provides the interfaces and protocols needed by the users. It combines the functionalities of the session layer, the presentation layer and the application layer of the OSI model.The functions of the application layer are −It facilitates the user to use the services of the network.It is used to develop network-based applications.It provides user services like user login, naming network devices, formatting messages,  and e-mails, transfer of files etc.It is also concerned with error handling and recovery of the message as a whole.This layer uses a number of protocols, ... Read More

The transport layer is responsible for error-free, end-to-end delivery of data from the source host to the destination host. It corresponds to the transport layer of the OSI model.The functions of the transport layer are −It facilitates the communicating hosts to carry on a conversation.It provides an interface for the users to the underlying network.It can provide for a reliable connection. It can also carry out error checking, flow control, and verification.The protocols used in this layer are −Transmission Control Protocol, TCP − It is a reliable connection-oriented protocol that transmits data from the source to the destination machine without ... Read More

The Internet layer is responsible for logical transmission of data packets over the internet. It can be compared to the network layer of the OSI model.The main functions of the internet layer are −It transmits data packets to the link layer.It routes each of the data packets independently from the source to the destination, using the optimal route.It reassembles the out-of-order packets when they reach the destination.It handles the error in transmission of data packets and fragmentation of data packets.The protocols used in this layer are −Internet Protocol, IP − It is a connectionless and unreliable protocol that provides a ... Read More

The host-to-network layer is the lowest layer of the TCP/IP model and is concerned with the physical transmission of data. It is also called a network interface layer or link layer. It can be considered as the combination of physical layer and data link layer of the OSI model.The functions of this layer are −It defines how bits are to be encoded into optical or electrical pulses.It accepts IP packets from the network layer and encapsulates them into frames. It synchronizes the transmission of the frames as well as the bits making up the frames, between the sender and the ... Read More

TCP/IP Reference Model is a four-layered suite of communication protocols. It was developed by the DoD (Department of Defence) in the 1960s. It is named after the two main protocols that are used in the model, namely, TCP and IP. TCP stands for "Transmission Control Protocol" and IP stands for "Internet Protocol".The four layers in the TCP/IP protocol suite are −Host-to- Network Layer −It is the lowest layer that is concerned with the physical transmission of data. TCP/IP does not specifically define any protocol here but supports all the standard protocols.Internet Layer −It defines the protocols for logical transmission of ... Read More

The application layer (Layer 7) is the topmost layer of the OSI model. It specifies the interfaces and supports services to the end users for network access.The main functions of the application layer are as follows −It provides a virtual network terminal through which a user can log on to the remote host on the network.It provides facilities so that a user can access and retrieve files in a remote computer for local usage, as well as manage and store files on a remote computer from the local computer.It provides e-mail services.It helps to retrieve global information and services by ... Read More

The presentation layer (Layer 6) ensures that the message is presented to the upper layer in a standardized format. It deals with the syntax and the semantics of the messages.The main functions of the presentation layer are as follows −It encodes the messages from the user dependent format to the common format and vice versa, for communication among dissimilar systems.It is responsible for data encryption and decryption of sensitive data before they are transmitted over common channels.It is also responsible for data compression. Data compression is done at the source to reduce the number of bits to be transmitted. It ... Read More

The session layer (layer 5) is responsible for establishing, managing, synchronizing and terminating sessions between end-user application processes.The main functions of the session layer are as follows −It works as a dialog controller. It allows the systems to communicate in either half-duplex or full-duplex mode of communication.It is responsible for token management. Through this, it prevents the two users to simultaneously attempt the same critical operation.It synchronizes communication. It adds synchronization points or checkpoints in data streams for long communications. This ensures that data streams up to the checkpoints are successfully received and acknowledged. In case of any failures, only ... Read More

The transport layer (Layer 4) is responsible for delivery of an entire message from an application program on the source device to a similar application program on the destination device.The main functions of the transport layer are as follows −It delivers a message from a specific process of one computer to a specific process in another computer. The transport layer adds a port address to the header of the data packet.It divides a message into smaller segments such that each segment contains a sequence number along with the port address. It ensures that the segments arrive correctly at the receiver’s ... Read More

The network layer (Layer 3) controls the source to destination delivery of data packets across multiple hops (nodes). It controls the operation of the subnet.The main functions of the network layer are as follows −It is responsible for routing packets from the source host to the destination host. The routes can be based upon static tables that are rarely changed, or they can be automatically updated depending upon network conditions.The data link layer assigns the physical address locally. When the data packets are routed to remote locations, a logical addressing scheme is required to differentiate between the source system and ... Read More