R12. What advantage does a circuit-switched network have over a packet-switched network? What advantages does TDM have over FDM in a circuit-switched network? Packet switching network is not suitable for real time services. In circuit switched network it can give end to end bandwidth during a call. In the packet switched network it cannot guarantee any end to end bandwidth. In circuit switched network Quality of service (Qos) is guaranteed while in packet switched network it is not guaranteed and packet switched network might have delay and time insensitive. Time division multiplexing (TDM) has an advantage over Frequency division multiplexing(FDM) as it gives bandwidth saving and there is low interference between multiplexed signals. R22. List five tasks that a layer can perform. Is it possible that one (or more) of these tasks could be performed by two (or more) layers? The layer can perform the five following tasks, Error control Flow control Segmentation Multiplexing Connection setup Yes, It is possible to one of these tasks can perform by two layers. For example, error control can be performed at two or more layers. R23. What are the five layers in the Internet protocol stack? What are the principal Responsibilities of each of these layers? Application layer: In this layer the user actions can be performed by the computer. It is the interface between user and computer and it supports for network applications. Example, transferring files Transport layer: It is used to
3: Network Layer: The use of network layer is switching and routing technologies. It demonstrates logical path and virtual circuits for transferring data from one node to
Layer 6: Presentation - Layer 6 takes the data provided by the Application layer and converts it into a standard format that the other layers can understand.
The fifth layer is the session layer this establishes a connection,this layer makes and sets up the connection using co ordinates and could terminate conversations links. the session layer produces services that make authentication after an interruption and not only that but it can reconnect.and as well as the transporting layer it can also have the TCP and the UDP can provide services for all most all applications.An application layer is an abstraction layer that specifies the shared protocols and interface methods used by hosts in a communications network. The application layer abstraction is used in both of the standard models of computer networking; the Internet Protocol Suite (TCP/IP) and the Open Systems Interconnection model (OSI model).Although both models use the same term for their respective highest level layer, the detailed definitions and purposes are different.In TCP/IP, the application layer contains the communications protocols and interface methods used in process-to-process communications
• “Application - The Application Layer is the layer that most network users are exposed to, and is the level at which human communication happens. HTTP, FTP, and SMTP are examples of the application layer protocols the Patton-Fuller will now be utilizing for communicating electronically” (Network Design, 2012).
1. Application (in terms of cabling infrastructure): The application layer is the OSI layer closest to the end user, which means both the OSI application layer and the user interact directly with the software application. When determining resource availability, the application layer must decide whether sufficient network or the requested communication exists.. (OSI_model#Layer_7:_application_layer)
This makes sure the data transferred is in the right order, error free and reliable from beginning to end. The Network Layer is the third layer of the model and its function is to interpret the network addresses into physical addresses and figure out how to direct them from the sender to the receiver. The next layer is the Data Link Layer, this is the second layer and it separates the data it receives from the Network layer into specific frames so they can be transmitted by the Physical layer. Frames are packages for moving data, they include the raw data, the sender and receiver’s addresses, as well as error checking and control information. This makes sure the frames are delivered to their destination without any problems. The physical layer is the first layer and the lowest, the protocols at this layer recognize and receive the frames from the Data Link layer. They also monitor data error and set data transmission
In the seven layers of the OSI, control is passed between layers. The model is theoretical, but tells us how a network takes the data sent from the application all the way down to the physical layer and out, to in the physical layer and back up all the way to the application layer. This Model has nothing to do with the actual functions of the process. Instead it is a concept of the framework, so the complexities of a network can be broken down and understood (Beal, 1999).
Transmission Control Protocol/Internet Protocol (TCP/IP) are the basic communication protocols, which were designed to provide low level support for internetworking. This term is generally also used to refer to a more generalised collection of protocols developed by the internet community and U.S. Department of Defence.
The Application layer within the OSI reference model is where the application and the user communicates. In other words, the application layer is the ending of data that is transferred in visual form to the user. This layer provides the interface between the applications we use to communicate and the underlying network over which our messages are transmitted. The Application Layer functions are to provide the interface for application-specific protocols commonly used such as HyperText Transfer (HTTP), file transfer (FTP), Simple mail transfer (SMTP), Internet message Access (IMAP),
Layer 3 is the network layer and utilises multiple common protocols to perform routing on the network. Protocols consist of the Internet Protocol (IP), packet sniffing and DoS attacks such as Ping floods and ICMP attacks. Because of their layer 3 nature, these types of attacks can be performed remotely over the Internet while layer 2 attacks primarily come from the internal LAN.
The internet layer is built up of four core protocols: IP, IGMP, ICMP and ARP. Internet protocol (IP) is responsible for routing, IP addressing and breakdown/reassembly of data packets, address resolution protocol (ARP) is responsible for mapping an IP address to a device on the local network, internet control message protocol (ICMP) provides diagnostic information and error reports on lost packets, internet group management protocol (IGMP) controls who receives IP datagrams in a single transmission. The transport layer is built up of two core protocols: TCP and UDP. Transmission control protocol (TCP) sequences and acknowledges packets sent and their recovery when lost in transmission allowing the computer to make and maintain network conversations where applications exchange data, defined as a connection-oriented protocol meaning the connection is maintained until the programs has finished exchanging data. User datagram protocol (UDP) This is used to transfer small amounts of data when the use of error correction isn’t needed increasing the speed of the transmission, common in multi-player video games as the user will not need to receive packets of past events in the game so the error correction featured in (TCP) would be
6. Why is Ethernet technology more appealing to users than the rest of the LAN technologies?
Layer 5 which is the Session layer allows the applications to establish a session by connecting systems. It provides a synchronisation between communication computers as well as manages and terminates the session if required and this depends on how the communication will take place. It also provides operation such as simple, half duplex and full duplex.
The application layer: this layer allows different applications to communicate with each other’s. In order to exchange different data over the network connection, the protocols included in this layer set up the standards such as DNS, HTTP, FTP. The data coded in this layer will be encapsulated to transport layer for further packing.
The ability to send and receive data efficiently is the most important objective of networking computers.