...Describe the OSI Model and how it relates to a network. The OSI Reference Model is becoming more popular everyday because it is a useful tool for learning about networks. The OSI Reference Model is where the communication system (network) is broken down into seven layers, where each layer serves a purpose. The OSI Reference Model defines what each layer’s function is but does not specify actual services in the layers. So that the vendors can write device drivers for a device; and not be concerned about the higher layers, this speeds up the process. The seven layers are divided into three groups: 1) Application (upper) layer, 2) Intermediate layer, 3) and Network oriented (lower) layer. With this system the OSI Reference Model is convenient because you’re able to communicate with a different computer network. The WAN Network operates on the Physical and data link layer of the OSI Reference Model. What are some Protocols? The purpose of the OSI Reference Model is to determine how data should be transmitted between two points in a network. Its job is to consistently work with other products. On which layer do switches and routers operate? Layer two, three, and four the Presentation layer, Session, and Transport Layer is where the witches and routers will operate. If Routers operate on more than one layer, what is the difference? Routers operate on layer three then apply on layer two and the switch the packets. Layer two would be Ethernet and layer three is the operating...
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...OSI MODEL Joseph Lucero College America Abstract In this paper it is going to explain the OSI model and all the layers. There are 7 layers in total: the layers are Application, Presentation, Session, Transport, Network, Data Link and Physical. It is going to explain what all the layers are and how they work in the OSI Model, it is also going to explain what every layer is. It is also going to explain why it was created and what the use for the OSI model is for today. You are going to know why we need the OSI model and how it evolved from the first time. You are also going to find out about the past history about the model and the other name is what called before. OSI Model The OSI model has been used for a long time. Why do we use it? OSI, formally known as the ISO OSI model, is the most standard model for networking communication. The ISO formed the OSI or Open System Interconnection, so that you can communicate and connect with another system over the network without having system specific configuration. The OSI model consists of 7 different layers: Physical, Data Link, Network, Transport, Sessions, Presentation, and Application. One reason why the OSI model was created, is so that the process of communication that were between two end points in a telecommunication network can be split into layers. The main reason why the OSI Model was created was to standardize the networking rules so that all the systems can communicate over the OSI reference model, which was a...
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...Checkpoint: Week 1 Day 5 OSI Model When we breakdown the OSI model you will see that in the seven layers of the design, a decision is made in the third layer, which WAN protocols operate on is known as the network layer. This layer carries out regular tasks such as pinpointing routings diagrams and end to end addressing. Some layers associate a unit also known as a brouter that works like a bridge and a router. Now on layers two thru four routers and switches work on these layers which are commonly known as the data link layer and the transport layer. As stated earlier on the network layer, which is layer two on the OSI model, is where the routing and addressing are carried out. In the OSI model during the transport layer is where we see the mistake handling and the flow control at work. Finally, synchronizations and assemblies are finished on the fourth layer of the OSI model. Configured of various parts every layer conducts a unique role inside the network. Additionally, each layer incorporates everything to the data which is then transmitted point to point. Protocols at work during this time are known as the frame relay protocol, HDLC, and PPP. The protocol that works as a data link layer is known as the frame relay protocol in the OSI model. The HDLC means high level data link in the model, and the PPP is an additional protocol which works on different layers of the OSI...
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...The OSI Model Upon trying to decide what to write about, I decided to go with The Open System Interconnection or OSI Model for short. My reasons are simple. One, the OSI Model provides a ton of information to write about. Secondly, found it to be one of the most interesting topics. My objective is to obviously explain the different layers of the OSI Model. As well as how communication occurs, and the many other functions of the Model. The OSI Reference model is based on a proposal developed by the International Standards Organization (ISO). The original objective of the OSI model was to provide a set of design standards for equipment manufactures so they could communicate with each other. The OSI model defines a hierarchical architecture that logically partitions the functions required to support system-to-system communication. “The OSI model is a theoretical representation of what happens between two nodes communicating on a network.” (Network + Guide to Networks fifth edition) It goes on say “It does not prescribe the type of hardware or software that should support each layer. Nor does it describe how software programs interact with humans.” The communication in the model is defined by its seven layers, which divides the tasks into seven smaller components that can be easily managed. A task or group of task are assigned to each layer and each layer is reasonably self- contained so that the task assigned to each layer can be managed and updated independently. My...
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...Networking - Understanding The OSI Model The OSI is a useful model for understanding and developing computer-to-computer communications over a network. OSI stands for Open Systems Interconnection. This conceptual model groups network communication into seven layers of data: Application, Presentation, Session, Transport, Network, Data Link, and Physical. Today, we will be talking about: the history, the seven layers of data, the communication between two systems, and frame specifications of the OSI model. In the early 1980s, the ISO began working on the OSI model so that it would enable computer platforms across the world to communicate openly. The concept of the OSI model was provided by the work of Charles Bachman, Honeywell Information Services. Various aspects of OSI design evolved from experiences with the ARPANET, the fledging Internet, NPLNET, EIN, CYCLADES network and the work of IFIP WG6.1. The new design was documented in ISO 7498 and its various addenda. In the OSI, a networking system was divided into layers. Within each layer, one or more entities implement its functionality. Each entity interacted directly only with the layer immediately beneath it, and provided facilities for use by the layer above it. Protocols enabled an entity in one host to interact with a corresponding entity at the same layer in another host. Service definitions abstractly described the functionality provided to an (N)-layer by an (N-1) layer, where N was one of the seven layers of protocols...
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...OSI Model The Open Systems Interconnection (OSI) reference model is a way to standardize communication between networked computers and other devices. Since there are so many ways to connect and communicate, this task was too large for just one standard. It had to be broken down into seven parts and layer them so each layer adds to the data before sending it down or subtracts data before sending it up. Yet each layer does not need changes from another layer in order for it to function. Each layer can operate independently or as part of a team. It is truly a remarkable setup. There are four layers that WAN protocols operate. The session layer establishes, maintains, and terminates connections (sessions) between communicating applications. The transport layer does exactly what the name implies. It is the taxi for the data being transferred. The network layer establishes, maintains, and terminates connections with switching and data transmission technologies. The data link layer provides transportation of data from the physical layer. The physical layer deals with the switches and routers. There are two layers that deal with switches and routers: the network and physical layers. It sounds redundant, but it is not. The physical layer only deals with the routers and switches. Only the physical elements of network while the network layer does more. The network layer establishes, maintains, and terminates connections while the physical layer only deals with the drivers...
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...OSI Model Your Name University of Phoenix Introduction to WAN technologies Teacher Date “The OSI (Open Systems Interconnection) model was created by the ISO to help standardize communication between computer systems.” (Tech Terms, 2011) The OSI model has seven different layers which breaks up communications and uses multiple hardware standards, protocols and even other types of services. The seven layers of this protocol are the physical layer, data link layer, network layer, transport layer, session layer, presentation layer and the application layer. The layers which WAN protocols operate are at Layer 1 and Layer 2 which are the physical layer and the data link layer. You have the cables, routers, server, connectors, signaling and standards on the first layer and then you have the frame relay, HDKX, PPP and ATM which are the WAN protocols on the second layer. “The physical layer is responsible for establishing, maintaining and ending physical connections (point to point) between computers.” (University of Pittsburg) When you talk about routers on different levels in the OSI protocols a thing to remember is they can be doing processes on more than one level but they really only reside on the first level of the protocol. Layer 1 is actually concerned with the interpretation of the bit stream and turning it into an electrical signal that will be carried across a physical medium. Then the data link layer or layer 2 will really define the format of the data ion the network...
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...OSI Ned Leeds CMGT/245 CMGT/245 Version 2 IS Security Concepts October 28, 2013 LAYER 1 - PHYSICAL The physical layer is mainly responsible for establishing, maintaining and ending physical connections (point to point) between computers. This layer is concerned with the actual interpretation of the bit stream into an electrical signal that can be carried across a physical medium. The protocols at this layer deal with the binary transmission, voltage levels, and data rates. This layer would also specify physical medium properties such as cables and network cards. LAYER 2 - DATA LINK The data link layer defines the format of data on the network. All of the data sent through the network are made into a frame which is performed at this level. The frame is a uniform way of sending the data along with address information and error checking capabilities. CRC is used for the error detection at this level. The receiving end the CRC fails at this level there is a request back to the sender for retransmission of this packet. LAYER 3 - NETWORK The network layer basically handles all of the addressing issues. This layer addresses packets, determines the best path or route will manages network problems such as data congestion. There are three ways in which the packets are routed to their destinations. There could be a static route through the entire network that will never be changed. This could also be a static line only used during a particular session between the sender...
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...CheckPoint: OSI Model Due Week 1 Day 4 Describe the OSI model and how it relates to a network in 200 to 300 words. Your response should include answers to the following: - On which layers of the OSI model do WAN protocols operate? - What are some of these protocols? - On which OSI layers do switches and routers operate? - If routers reside at more than one layer, what is the difference between the OSI layers? • On which layers of the OSI model do WAN protocols operate? WAN protocols function at the lower three layers of the OSI reference model: the physical layer, the data-link layer, and the network layer. • What are some of these protocols? Frame Relay- is a high performance WAN protocol that operates at the physical and data-link layers of the OSI model. The Frame Relay allows for use across ISDN (Integrated Services Digital Network) interfaces. It is a good example of a packet-switched technology. LAPB, which stands for, “Link Access Procedure Balanced” – is a data-link layer protocol that manages communication and packet framing between devices. It shares the same frame format, types and field functions as SDLC and HDLC. However, unlike either of those, LAPB is restricted to the ABM transfer mode and is appropriate only for combined stations. LAPB, circuits can be established by either the data terminal equipment, or the data circuit-terminating equipment. The station initiating the call is determined to be...
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...OSI Model Protocol Keisha Bullock NTC 361 December 9, 2013 University of Phoenix (Axia) Bruce Yamashita OSI Model Protocol Open System Interconnection (OSI) is a recommended suggestion for how messages should be transferred between any two users in a telecommunication network. The purpose of the OSI is to direct product implementers so that their items will regularly work with other items. The OSI model outlines seven layers of function that happens at each end of a message. The main purpose of the Open System Interconnection is that the communication procedure between two end points in telecommunication networks can be split up into different levels with each level having its own set of responsibilities ("OSI (open System Interconnection)", 2000-2013). The OSI slits the telecommunication into seven levels which is the application level, the presentation level, the session level, the transport level, the network level, the data link level, and the physical level ("OSI (open System Interconnection)", 2000-2013). The layers are broken up into two sets. The higher four levels are used when a message is transmitted from user to another user. The bottom three levels are exercised when any message passes through the main computer. Messages planned for this computer go through to the higher levels and messages intended for some other computer are not distributed up to the levels but are advanced to other host. The application level offers multiple services to the...
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...The OSI Model The OSI Model The OSI model describes how data flows in a network. From the top, highest level containing applications for the everyday user down to the bottom level of the physical connections, data and information passes through every layer which in turn can talk to the layers above and below it. Every layer is made up of complicated software. When that software and its components receive information, commonly called packets, from another source it checks it and then sends it back through if necessary (Breithaupt & Merkow, 2006, Chapter 12). The OSI Model is comprised of seven layers, each distinctly different but yet each function and communicate with the others. Application layer The application layer is the one most computer users are the most familiar with, whether it is known to them or not. This is where user forward software operates, such as e-mail and the beloved World Wide Web. The application layer handles resources, files, and verifications necessary for these things to operate. Presentation layer The presentation layer is aptly named. Its main function is to present decrypted or encrypted data to the application layer. Examples of this process include viewing video streams or listening to music online. Session layer The session layer creates a session, or connection between processes running between two separate workstations or platforms. A session includes creating the connection between the systems and eventually terminating...
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...This paper will discuss the Open System Interconnections (OSI). “The OSI was developed by the international Organization for Standardization (ISO) as a Model for a computer protocol architecture and as a framework for developing protocol standards. The OSI model consists of seven Layers: Application, Presentation, Session, Transport, Network, Data Link, and Physical.” (University of Phoenix) The Application layer supports application and end user processes, also it provides application services for file transfer, e-mail, and other network software service. Telnet and FTP are applications that exist completely in the application level. The Presentation layer provides self-rule from differences in data representation by translating from application to network format and vice versa. This layer works to convert data into the form that the application layer can accept. It formats and encrypts data to be sent across a network, providing lack of restrictions from compatibility problem. The Session layer launch manages and come to an end connection between applications. This layer sets up, brings together, and terminates conversations, exchanges, and dialogues between the applications at each end. The Transport layer provides crystal clear transfer of data between end systems, or hosts, and is responsible for end to end error recovery and flow control. This layer guarantee complete data transfer. The Network layer offers switching and routing technologies, creating logical paths...
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...The following table compares the functions performed at each OSI model layer. Layer | Description and Keywords | Application (Layer 7) | The Application layer integrates network functionality into the host operating system, and enables network services. The Application layer does not include specific applications that provide services, but rather provides the capability for services to operate on the network.Most Application layer protocols operate at multiple layers down to the Session and even Transport layers. However, they are classified as Application layer protocols because they start at the Application layer (the Application layer is the highest layer where they operate). Services typically associated with the Application layer include: * HTTP * Telnet * FTP * TFTP * SNMP | Presentation (Layer 6) | The Presentation layer formats or "presents" data into a compatible form for receipt by the Application layer or the destination system. Specifically, the Presentation layer ensures: * Formatting and translation of data between systems. * Negotiation of data transfer syntax between systems, through converting character sets to the correct format. * Encapsulation of data into message envelopes by encryption and compression. * Restoration of data by decryption and decompression. | Session (Layer 5) | The Session layer's primary function is managing the sessions in which data is transferred. Functions at this layer include: * Management of multiple sessions...
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...OSI Seven Layer Model The Open System Interconnection model (OSI) defines internetworking in terms of a vertical stack of seven layers. The upper layers of the OSI model represent software that implements network services like encryption and connection management. The lower layers of the OSI model implement more primitive, hardware-oriented functions like routing, addressing, and flow control(Mitchell, 2011).The seven layers of the OSI model are - * Physical * DataLink * Network * Transport * Session * Presentation * Application Physical Layer is the first layer of the OSI model and deals with the physical aspects of the media being used to transmit the data. This layer is also responsible for bit-level transmission between network nodes. Specification examples include Ethernet, 802.3, 802.5, and Fiber Distributed Data Interface. Data Link Layer is the second layer of the OSI model and is responsible for ensuring there are data link connections between two network entities so that data can get across a specific medium and individual links. Examples of this layer include IEEE 802.3, IEEE 802.5, Token Ring, and Frame Relay. Network Layer is the third layer of the OSI model and is responsible for the packet sequencing, congestion control, and error handling. This layer also provides paths for data to transfer through the network. At the Network layer routers began to operate. Examples of this layer include the use of Internetwork Protocol (IP)...
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...TCP/IP OSI MODEL TCP/IPMODEL OS MODEL Eric Jones 1/31/2014 TCP/IP MODEL OS MODEL TCP/IP is a set of protocols that allows communication between to different computers. It separates networking functions into different layers. Each layer has a different task that is similar to another layer or functions. The TCP/IP is a short version of the OS Model it has four layers instead of seven. TCP/IP is the language of how computers communicate with other computers through the internet. TCP/IP is not a single network protocols it’s a suite of protocols. The TCP layer handles the message being sent and breaks it down into small units called packets which are transferred over to the network. The IP layer is most concerned about transmission. By using unique IP addresses assign to every active receiver on the network. TCP/IP combines the OSI application and the presentation layers and supports flexibility in hostnames and also handles Dns errors and mapping domain names. The OSI also known as the reference model it provides a method of standards and protocols which can be compared to assist in other connectivity. Most developers today now use a reference model/OSI Model learn how transmissions are framed and created to translate to other systems. I it begins with the physical layer of the transmitting system and travels through the other layers to the application layer. Once the data reaches the application layer it is processed by the receiving system. In some cases, the...
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