The Seven Layers of the OSI Model Kevin Ludwig Bryant and Stratton College TECH 140 Khaled Sabha 12.08.2009 There are seven layers in the OSI model. Each layer has a function or purpose that is used to set up a network. The International Organization for Standardization began to develop the OSI framework in 1984. The purpose was to have each layer interact with the layer directly beneath it. The layers are starting from the top: Application, Presentation, Session, Transport, Network, Data Link and Physical. The Application layer has the function of providing interface between software applications and network for interpreting the requests and requirements for applications. “This top layer defines the language and syntax …show more content…
The functions of hardware in the OSI model support similar to the functions of the model layers. In the OSI model there are also Protocols and Standards. “ISO defined a group of protocols for internetworking communications based on the OSI model.” (Network Protocols Handbook, 2007, p 217-218). Application consists of BOOTP, DHCP, DNS, FTP, HTTP, HTTPS, IMAP4, PING, POP3, NSLOOKUP, NTP, SFTP, SMTP, SNPM, Telnet and TFTP. The Presentation layer consists of MIME, SSL and TLS. The Network layer consists of ARP, ICMP, IGMP, IP, IPSec and RARP. The Data Link layer possesses L2TP, PPP, PPTP and SLIP. Finally the Physical layer has IEEE 802.3, 802.5, and 802.11. These protocols are the most common in the OSI model. By adhering to this standard model of communications, modem networks, including the Internet have come into existence. For anyone interested in implementing in today’s modem networks, an understanding to the OSI model and its various layers is vital. This standard of communications presents the foundations for today’s entire modern network hardware and software. References OSI MODEL. (2009). In Computer Desktop Encyclopedia (p.01). Pennsylvania: Computer Language Company Inc. Network Protocols Handbook (2007). Protocols Guide: Iso Protocols in OSI7 Layers Reference Model. P
A: OSI stands for Open System Interconnection. The main aim of the OSI layer is to implement protocols of a networking framework.
Patton-Fuller Community Hospital uses layers 1, 3, 4, 5, 6, and 7 of the OSI model. The OSI model is broken into seven layers that play a major important role in how the model functions on a functioning level. Patton-Fuller Hospital uses certain layers of the model, below is the function of each layer:
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).
The OLI theory refers to ownership, location, and internationalization (Dunning, 2000). It is a basic theory proposed by John Dunning in an attempt to explain the incentives behind the MNEs going overseas (Dunning, 1993), organizational forms of MNEs, the MNE’s location choices, and the decision choice that lay between FDI and its alternatives like international licensing, trade and outsourcing (Javorick, 2004). The Ownership advantage is how a firm’s tangible and intangible assets are used in overcoming extra costs of doing business in the global market and explain why a home-grown country firm as opposed to a foreign firm manufactures in a foreign country. Location advantage offers explanation to why a home-based MNE may choose to manufacture in a foreign country instead of home country (Helpman et al., 2004). Lastly, internationalization advantage is attributed to why a home-based MNE may choose FDI instead of licensing to gain production in a foreign country (Athreye and Chen, 2009).
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)
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
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 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.
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:
Which layer of the OSI reference model handles logical addressing (IP addresses) and routing traffic?
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 RADIUS also known as Remote Authentication Dial-In Service, which takes place at the application layer also known as layer 7 of the OSI model. It is a protocol that is used to communicate to and from the NAS (Network Access Server) and also to the AAA server. RADIUS was developed as access server authentication and accounting protocol. It is used as both a client and server protocol that is also a software that allows remote access to servers to allow servers to communicate with the main server, by doing this it allows the server to authenticate dial-in users and allows authorised access to the services that was requested. RADIUS is an industry standard that is used by a various number of network product companies, it is also a proposed IETF standard. The RADIUS is known to be considered as a connectionless service
The ability to send and receive data efficiently is the most important objective of networking computers.