Osi Model Essay

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)

Layer 3: Network - The way that the data will be sent to the recipient device is determined in this layer. Logical protocols, routing and addressing are handled here.

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.

A communications protocol characterizes the guidelines for sending pieces of information starting with one hub in a system then onto the next hub. Conventions are regularly characterized in a layered way and give all or part of the administrations indicated by a layer of the OSI reference show. A convention characterizes the operation of the convention and may likewise propose how the convention ought to be actualized. It comprises of three sections:

The OSI Model is a model is used to define how data is theoretically passed on a network. Each layer is responsible and has its own duties for a network. The name of layer 3 in the OSI is the Network Layer. This layer is responsible for creating the paths for the transmission of data across the network. This layer provides routing and switching capabilities, as well as, internetworking, congestion control, and packet sequencing (Beal, 1999).

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

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),

The layer starts from 7 being the top layer and 1 being the lowest layer of the OSI model. Application layer- Serves as the window for users and application processes to access networks services like web browser (Internet explorer, Mozilla) protocols – DNS & SSH etc. Presentation layer- Translates data from the format send into the format that program can understand. Session Layer- Starts and end session and also keeps them isolated protocols- SMB,NFS, Socks and allows session establishment between processes running on different stations. Network- Determines addressing method for being transmitted. Transport- Defines ports and reliability protocols- TCP, UDP. Network- logical or IP addressing: Determines best path for the destination protocols- IPV4, IPV6, ICMP, IPsec. Data link- Contain data into a frame that contains a header with a destination. Switches, Mac addressing protocols- PPTP, Token Ring. Physical Link- Determines the hardware used and the method used for data transmission like cables, network interface cards, electrical

The OSI (Open System Interconnection) model is a set of specifications that allow computers around the world to openly communicate. It is pivotal to understanding and developing computer to computer communications in a network. Each layer plays a role in the process of sending and receiving data. The application layer is the top layer (layer seven) it promotes communication between programs and lower-layer network services. The services at this layer allow the network to decipher a program's request and the program to decipher data sent from the network. The Application layer protocols, programs handles formatting, procedure, security, synchronization, and any other requirements with the network. The Presentation Layer (layer 6) acts as a translator. For instance these protocols decode the jpg/jpeg files sent within the Web server’s HTTP response. So, in the last step (the Application layer) we enter the Web address and it took us to the Web site. This step allows us to see the images and content of the site. The Session Layer (layer 5) regulates and controls the communication between two nodes on the network. It is an ongoing exchange of data between the two and keeps the connection between them for the duration. It keeps the communication secure, detects whether or not the communication has been cut off and if it has it determines where to restart the

• “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).

Which layer of the OSI reference model handles logical addressing (IP addresses) and routing traffic?

| Using your textbook and web research, in your own words, summarize what you have learned about LAN modeling using OPNET ITGuru. Requirements: Minimum one paragraph per section; best practice is two or more

10. Which of the following statements is true when comparing the OSI and the TCP/IP model as defined in RFC 1122? B) The lower four layers of TCP/IP define the same kinds of functions as the matching layer numbers from OSI.

One may wonder why the OSI model is so successful. The author believes that the OSI model’s manner of network-function organization is the cause of OSI’s great success: the model defines clearly each function that is essential in inter-computer communications, as well as the relationship between each of these functions. The author will further contend that the scope of OSI’s method of communication-functions organization is not limited to inter-computer communications. Rather, the model’s clear method of organizing the elements of a communications system is an efficient tool for analyzing the elements of any method of communication. The author will now demonstrate this point by evaluating the functionality of the Pony Express according to the layers of the Open Systems Interconnection reference model.

Peterson, L. L., & Davie, B. S. (2011). Computer Networks, Fifth Edition: A Systems Approach (The Morgan Kaufmann Series in Networking). Morgan Kaufmann.