• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

The seven layer osi model

Extracts from this document...

Introduction

Ricki Lambert Communications Technology The seven layer OSI model - D3 Introduction The OSI seven layer model is the method in which data is sent and received through a communications channel. As the name clearly states there are 7 processes that need to be undertaken in order for this to happen. However, for data to be sent and received successfully it needs to undergo the process twice, the second time in reverse order. An example of this can be seen below; The first layer we come across, and the last layer when sending is application. Let's have a look at the application layer a little further. Application It is important to consider what an application really can be when applying it to computing. Application is a software program designed to perform a specific task or group of tasks, such as word processing, communications, or database management. In the case of communication we have many applications, such as messenger software (yahoo or msn), chat rooms, most prominent though is the e-mail based software used on a daily basis by almost every internet user. An application of this type maybe outlook express, or a standard web based e-mail account. Application is considered very basic and is something which is visible to the user. ...read more.

Middle

This makes up a huge part of the transportation process however differing protocols to TCP can be used. TCP/IP is one of the most common procedures in computing communications and plays a big part in transportation. This goes to show the relationship between the network layer and the transport layer. The network layer is the IP and the TCP is part of the transport layer. There are many specific ways in which the transportation layer of the model works and these shall be listed below; * Segmentation, packaging and reassembling - This process is very similar to what occurs in the memory management sub system of an operating system. Large amounts of data are segmented into smaller pieces on the source machine and are then sent, this is then reassembled on the destination machine. * Flow control - This is implemented to ensure that time differences between sender and receiver are dealt with and corrected appropriately. Network The network layer is where a router will reside and is the area in which differing protocols reside. It is possible to think of the network layer of doing the following task; if two differing networks are involved in communicating then certain pathways need to be followed, ultimately this is the routers job but it co-insides with the network layer. ...read more.

Conclusion

This happens for both sending and receiving and also occurs in wireless networking. The devices such as the routers, hubs and modems are the ones responsible for possessing the data. They don't intend on knowing any of the message being sent they are just interested in the raw data, although instead of viewing this as a 0 or a 1 they see it as a light pulse or electric charge. The two layers, physical and data link are so closely related that it is impossible to define hardware that belong to one or the other. What is tending to happen nowadays is that the physical layer is being divided in to sub categories so that different network Medias can be supported by the same technology, this allows them to increase in performance and why we have seen the following, Ethernet, Fast Ethernet and 10-Gigabit Ethernet. Conclusion In concluding it is important to remember that all stages of the seven layer model are equally important even if some functions overlap. They are vital in the way in which we communicate and are always developing to suit new technologies and hardware. Another thing to consider is the actual definition of the seven layers. This is not true as really the system is an eight layer concept where the eighth layer is actually the network engineer or user. In some cases the eighth layer is used to define the way in which the system is protected so it represents the security features. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Computer Science section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related AS and A Level Computer Science essays

  1. Marked by a teacher

    LAN & Topologies & Data Flow

    3 star(s)

    Any normal server can be transformed into a file server. Indeed a file server is mostly used in a private LAN network, which is probably password protected so user's from outside the network cannot hack it. Ethernet cables are normally used to connect servers to a network.

  2. Marked by a teacher

    The systems development life cycle (SDLC) is a conceptual model used in project management ...

    3 star(s)

    Sometimes, the coding needed to perform the system functions may be too intensive and the potential gains that prototyping could provide are too small. Prototyping is especially good for designing good human-computer interfaces. "One of the most productive uses of rapid prototyping to date has been as a tool for iterative user requirements engineering and human-computer interface design."

  1. The Seven Domains of IT Infrastructure

    Therefore, strict security is necessary to keep the system safe from attacks. If measures aren't taken to reinforce high security, security breaches are bound to occur. High security prevents hackers from gaining access to sensitive data and information. Remote Access can be gained through a VPN connection.

  2. Control Unit, Memory Unit, and Arithmetic Logic Unit. The CPU or Central Processing ...

    from time to time, implying that the original software will need to be erased so that it can be replaced. Losing these files when the machine is switched off is not a problem because they will have been saved on secondary storage. -ROM is used to store the bootstrap program.

  1. Logic and Logic Gates

    The line above stands for NOT. The circle on the symbol is called a bubble and is generally used to indicate the inverted (active-low) input or output. Truth Table Input Output AB Q 00 0 01 1 10 1 11 1 3. OR GATE There are two inputs so the equation is 22 = 4.

  2. Flexible Architectures in Communication Security Application

    The protocol is used by web servers to establish secure HTTP connections. For very short sessions, fast public-key cipher processing is critical for high transaction throughput. For longer sessions, private-key cipher performance becomes more important. Figure 2 illustrates the SSL run-time breakdown by server processing type.

  1. Introduction of Communication

    Users can connect to WAP sites: websites written in, or dynamically converted to, WML (Wireless Mark-up Language) and accessed via the WAP browser. - From http://en.wikipedia.org/wiki/Wireless%20Application%20Protocol accessed 05/12/2009 WAP can also be used to download videos. Advantages Portability, WAP is used by mobile phones to get information via an application such as weather reports.

  2. Small Office Network Implementation - hardware and security.

    Normally workstations are optimized for displaying and manipulating complex data such as 3D mechanical design, engineering simulation results, and mathematical plots. Consoles usually consist of a high resolution display, a keyboard and a mouse at a minimum, but often support multiple displays and may often utilize a server level processor.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work