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The OSI Model |
| Written by Michael D | |
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The Open Systems Interconnection (OSI) Model was developed by International Organization for Standardization (ISO) in the 1980s as an attempt to make communication between any two systems possible.
The 7) The Application Layer represents the interface between the end-user and the network. Some of the protocols that reside here are HTTP, SMTP, or FTP. Generally speaking all applications that you use to connect to something resides here: Internet Explorer, Mozilla Firefox, Outlook Express, Yahoo Messenger, etc. 6) The Presentation Layer transforms data to make a general interface to the Application layer. It decodes, encodes and compresses data for the upper layer. You will notice that every layer serves the layer above it. 5) The Session Layer includes the sessions between computers. It opens, maintains and terminates the connections between the client and the foreign server. On layers 5-7 the data package is in the form o data stream. 4) The Transport Layer provides data flow between computers; it relieves the upper layers of the concern of getting and sending the data. This is the layer where Transmission Control Protocol and User Datagram Protocol reside. Here the data is cut in segments to achieve a steady flow no matter of the differences in connection bandwidth between hosts. 3) The Network Layer makes it possible to transport the data between networks. In front of the segments a network header is places, telling the sender's IP address and the destination IP address. This header remains constant and will be just read and not changed by the equipments during the communication. There's also a IP or Network Trailer at the end of the package, containing the checksum that validates the data. Routers operate at this layer to handle network addresses. 2) The Data Link Layer takes the bits from layer one and arranges them into data structures called frames. It also uses a Frame Header stating the sender MAC address and destination MAC address in it. Note that these values change by passing through network nodes like router interfaces or servers. To make it clearer, look at the following picture.
A client that is part of a network attached to us sends a packet to tutorial5.com. The packet will have: Sender's IP: 192.168.17.1 Sender's MAC: MAC (1) Destination IP: 10.0.0.2 Destination MAC: MAC (2) - Gateway's address After leaving the router, the sender's MAC becomes MAC (3) and the destination MAC becomes MAC (4). 1) The Physical Layer defines the electrical part of the communication: the binary signals that are transmitted and received in the data exchange. As you probably expected, the data packet looks here something like 110011000011001100.
written by jagmeet , July 06, 2007
can u please explain all the layers in one example
written by sonia , July 17, 2007
Hi, m summer trainnie in wipro.m doing a project in networking.wanted to know more about The OSI Model.plz send me some details of the same.thanx
written by Mihai Dobos , July 18, 2007
Hello Here are some links that offer some detailed informations on the The OSI Model http://www.cisco.com/univercd/cc/td/doc/cisintwk/ito_doc/introint.htm http://en.wikipedia.org/wiki/OSI_model Hope this is useful to you. I will soon post another article on studying and end-to-ent communication between a FTP client and server based on the The OSI Model and the TCP/IP suite. Best regards.
written by Ananda P S , July 29, 2007
Hi All This is Ananda ..... I got all the requirements from that website.
written by pr babu , August 06, 2007
Now a days how many layers used with tcp/ip
written by Mihai Dobos , August 23, 2007
Hello The TCP/IP model is used by almost all network devices; but the The OSI Model still stands as a good troubleshooting standard for any data communication. Best regards.
written by anks , August 27, 2007
hey all link very really ver helpfull. as i am totally beginer in networking field, any one can send me link to get more about networking from basic to advance level. becoz i need it as i am on my summere training thanks for cisco and wikipedia link
written by nagaraju , September 05, 2007
it is better but i want explonation of each layer is The OSI Model
written by devanand .n , September 10, 2007
THE DOCUMENT IS REALLY FANTASTIC BUT NEED SOME MORE DETAILS ABOUT THE TRANSPORT LAYER BECOZ IT CONSISTS OF TCP AND UDP - NEED TO EXPLAIN ABOUT THE TCP AND THE UDP
written by Bafoday , September 14, 2007
I am a junior in college and need help understanding the The OSI Model, internet model, any help will be very appreciated.
written by Mihai Dobos , September 15, 2007
Hello Follow the links in the third comment directing wikipedia and cisco. Hope that works for you. Mihai D.
written by jack , September 27, 2007
Hi, in terms of The OSI Model, which layer does SOAP belong to? pls describe it briefly. Thanks
written by Mihai Dobos , September 27, 2007
Hello SOAP, or Service Oriented Architecture Protocol/Simple Object Access Protocol (both names are valid) is a protocol that resides at the Application layer. For a further reference, see http://en.wikipedia.org/wiki/SOAP please. Mihai D.
written by zarsh , September 29, 2007
hello what is mean by host layers and media layers. why these names are given to the The OSI Model zarsh
written by vickie , September 30, 2007
can i know as a data packet moves from the lower to the upper layers, waz will happens to the header? thx...
written by Mihai Dobos , September 30, 2007
Hello The packet looks like this on the layers: Layer 1: 10101001000 (binary) Layer 2: [Frame header][segments of data][Frame trailer] Layer 3: [Network header][Frame header][segments of data][Frame trailer][Network Trailer] Layer 4: [segments] - headers are removed for processing Layer 5,6,7: data stream, obtained from merging the segments Mihai D.
written by laura , October 03, 2007
hi this information is very useful for us student's expecially for me because i live in kosova EU and thanx aa
written by Sisi , October 11, 2007
hey im doin cisco but all this is confusing... i need to know how the OSI and TCP/Ip model link with encapsulation
written by amirul , November 01, 2007
Dear All I need to get CISCO CCNA certification.What can I do for best.Pls help me by more information. Thx @mirul This e-mail address is being protected from spam bots, you need JavaScript enabled to view it This e-mail address is being protected from spam bots, you need JavaScript enabled to view it This e-mail address is being protected from spam bots, you need JavaScript enabled to view it
written by Dima , November 07, 2007
Hi all, This is very useful =) Can u tell us about encapsulation and decapsulation? Encapsulation process happens when the message is sent from one computer to another, each layer adds new "header" to data units as they get passed from the Application Layer to the Physical layer. When the message is recieved, decapsulation strips "header" information on way up (Physical layer - Application layer). Is that right? ;) Best regards
written by Mihai Dobos , November 08, 2007
Hello Dima When Internet Explorer (or any browser) sends a HTTP request to Tutorial5.com, it will go down through the The OSI Model, open a socket at layer 4, then the OS will encapsulate the data using TCP/IP and add headers and trailers, then the network interface card translates this into binary and signals it on the line. (Going from Layer 7 to Layer 1) When the server recieves the request, it's interface will decode the signals, pass the data to the OS, which reads the informations from the headers and strips them off the packet, forwarding the data stream to the web server application. (Going from Layer 1 to Layer 7) So encapsulation/decapsulation is done by both sides, depending if they are recieving or transmitting data over the conversation. The The OSI Model is a theoretical way of describing a network conversation between devices. Different technologies and applications use the layer functions in different way. This is what happens in very short terms; hope that helped you to understand it better. Mihai D.
written by Krishna , December 09, 2007
hi Mihia, I also heard that the communication between to different hosts happen at the same layer i.e. application layer of A device talks with Application layer of B device and vice versa with all the layers. can you help me understand this clearly. Regards, Krishna
written by Noah , December 15, 2007
Hi there. this is Noah from Uganda well thanks very much for you support. but can you send me some links on how to config a router. thanks!! see ya Noah W.
written by sharif , January 16, 2008
i want to learn how to configure server system by vedio tips have any cd/dvd in market or any web link??
written by mahe , April 30, 2008
Hi, Excellent info on The OSI Model. I would appreciate if you provide good vedios for this The OSI Model. Regards, Mahesh Do you need more help? Ask now!
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| Last Updated ( Saturday, 23 June 2007 ) |
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