Q Assignment states all about networking model is very important and describes how data is transferred from one network Home, - ITECH1102 -NETWORKING AND SECURITY Introduction We find many people who are connected with the computer network daily all over the world. The data communication can be wired or wireless, most of them now takes place by way of packets of data transmitting from one or more networks. However, before working of these networks together, a common protocol should be taken. ISO model is called the International Organization of Standardization commonly known as OSI model. The ISO-OSI model is seven layer models focusing on integrated networking and communication system. A – The Data Link Layer (Layer2) Data Link Layer is called as the OSI model layer 2. The link layer can be described as the use for sending data to and from of a physical path of connections link. The mediums has link-layer condition for network and features are performed by link-layer that include such as substantial addressing, , mistake notification, network topology, outline sequencing as well as flow control (Almog, Saar, Raveh, & Goldenber, 2015). Network Topology Network topology has characteristics that figure out how they are linked to the devices in a network. Several sources let devices to be connected by a term called ring topology, most of the times the others use or require a star topology (Almog, Saar, Raveh, & Goldenber, 2015). The star topology is used to prevent the network from failure, with the help by connecting central nodes to all systems. Physical AddressingThe term Network addressing is not like the physical addressing. It gets distinguished between devices or nodes present in network, and put the traffic to be change through the network. In comparison, physical addressing focuses on the devices concerning link-layer level. The physical addressing is separated between individual devices in relation to physical mode (Venkataswami, Bhikkaji, Perumal, & Beesabathina, 2016). Frame Sequencing In data link layer the frame sequencing capabilities lets frames to be transmitted out of cycle on the receiving end of a transmission (Venkataswami, Bhikkaji, Perumal, & Beesabathina, 2016). The packet consistency can then be confirmed within the direction of bits present in the data link layer header. It is further transmitted next following data payload within the layer functioning. Error Notification Error notifications are been provided by data link layer that aware top layer of protocols in case of any error caused. When an error is subjected it is transferred on to physical link. Link-level errors results in the loss of a clocking sign, loss of connection, bugging, across serial connections and loss of a signal. Sometimes the result becomes failure of the isolated endpoint within the targeted governance of T1 or T3 link. Flow Control Flow control is part of the Layer 2 it let the devices on a link to notice any jam and then notify their downstream and upstream neighbors. The neighbor devices passes on the blocked data to their top layer protocols in order to change the flow of traffic (Venkataswami, Bhikkaji, Perumal, & Beesabathina, 2016). Data Link Sub layers The data link layer has certain set of sublevels that includes Media Access Control (MAC) and Logical link Control (LLC). The Logical Link Control sub layer helps to foster the process of communications occurs between devices within the series of connections of a particular network. The sub layer is connected to wires within field. Further, the link-layer frames to allow various peak layer protocols to disconnect a single physical link (Essinger et al., 2015). On the other hand, MAC sub layer attempts to handle the protocol admittance within the procured physical network medium. While MAC addresses actions prearranged to all ports on a device, or occasionally various devices. B. Internet (Network) Layer The internet (network) layer is the tertiary layer in OSI model of computer networking system. This layer gives support to end to end communication through the medium of network switches and routers. This layer manages the transmission of data from the lower layers to the upper layers via network connection and internet sources (Morales, Ruiz, & Velasco, 2017). The three main functions of Network Layer are as follows:- 1. Forwarding function At the key of the router, when the data packet enters, the network layer enables the data to reach the desired source. 2.Determining the path It is important to check the path of the concerned data packets from the source to the end is recognized by the network layer. 3. Setting up the router Before the data flows into the path, few networks need the router to be labeled. This is done by the internet layer. Internet as a connection-less protocol 1. Datagram packets are part of the connection-less network services. 2. In the network layer the internet works as a data packet exchanging source. 3. Internet diverts the packets to its desired destinationthrough a collective path. 4. In this layer, each protocol functions in a separate manner. 5. Internet is a vast web of several connected network resources. Thus, it is not possible to know the characteristics of the path before making a connection between the source and the destination(Casimer et al., 2016). IPv4 In internet layer the Internet Protocol version 4 (IPv4) is a connection-lessservice and is used as a delivery mechanism to the transport layer. The IPv4 is a protocol which is less dependable than others.However, to make it reliable, IPv4 should be matched with the transport layer protocol for a smooth functioning of the networking system. The IPv4 uses the advanced stage of datagram transmission which means, that every datagram is sent separately and tracking the different route to the destination. Owing to this, some of the data packets can lose their way on their journey to the destination (Morales, Ruiz, & Velasco, 2017). Datagram Datagrams are the information packets in the IPV4 layer, and also a variable which is composed of the networking information and headers.A header which is an important component of routing and release has the size of 20 to 60 bytes. Fragmenting the data Data from several varied networks travels through the networking system passing this layer. Every router on the way segments each frame and sends it as data packets to the destination, encapsulating on the way(Madakam, Ramaswamy, & Tripathi, 2015). Maximum Transfer Unit The size of the data being sent should be less than the maximum permissible size so as to ensure smooth passing of the required messages. Network Devices (Hub, Repeater, Bridge, Switch, Router) 1. Repeater – A networking device that stimulates the signal over the similar path so as to avoid any weak signal, and transmits the data over the same networking path. Repeaters cannot intensify the signal strength, but as it has dual port the signal reaches the desired place in bits(Gal et al., 2017). 2. Hub – This device is used for multiple port networking. Connecting many wires coming from varied divisions, it links several networking series but as they are unable to segregate the data, the information is sent to the linked devices. There are two types of hubs:- Active Hub: -This type of hubs has their own supply of power, and can increment the signal and send it to the desired network path. They are used between nodes at both end and works as a repeater and a wiring connectivity source. Passive Hub: - These hubs accumulate the wiring and the power connection from the active hub and send the networking signals as they are, and do not increase any area in between the nodes (Karagiannis, Chatzimisios, Vazquez & Alonso-Zarate, 2015). 3. Bridge – A bridge is an example of networking device that functions in relation to data link layer. A bridge is a repeater. It is also used for communicating the two Local Area Networks working on the same protocol (nodes). Types of Bridges Transparent Bridges: - The transparent bridge acting as the targeted the locations of the bridge sometimes are completely unaware of the bridge’s continuation. For example, in certain case, a bridge is added or deleted from the network allwoing disintegration and reconfiguration of the locations that is not important. It sues two processes such as bridge learning and bridge forwarding. Source Routing Bridges: - the source routing bridges help in determining the targeted position where the simulated outline denotes which route to track within the network line. The bridge on the other hand has an easier way to check frame by transferring a particular frame named as Discovery Frame. It forms into multiple connectivity within the wide network using all possible directions to channel networking. 4. Switch – A switch is referred as multi port bridge that enable connectivity swifter and faster with just a push. It doesn’t hold onto barrier and helps in boosting capability and performance. Switch is the most common example of example of data link layer device. C. The Transport Layer (Layer4) In the OSI networking model, the transport layer functions as a separator of the flow of information, and removes any hurdles in the networking path. The processing on the fourth layer is done via an informational segment known as the Service Data Unit, which also involves the base of the protocols that make the transport layer. The layers five to seven get the access of networking suites from this layer (Gal et al., 2017). Gateways and firewalls are used in the transportation layer (Sweeney, 2016). Conclusion A networking model is very important and describes how data is transferred from one network part to another. It is almost same like an address blueprint defining the procedure in building a house. A computer networking model states the rules and devices that are significant in creating the structure of a systematic networking pathway. Each of the protocols in the networking system defines the services,devices, paths, and the methods that are essential for the complete process of web services and data transfer to go on properly.