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Between TCP/IP model & ISO/OSI model, which one is more advantageous than the other and why?
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on 2010-10-22 09:30:00In the TCP/IP model of the Internet, protocols are deliberately not as rigidly designed into strict layers as the OSI model.[6] RFC 3439 contains a section entitled \"Layering considered harmful.\" However, TCP/IP does recognize four broad layers of functionality which are derived from the operating scope of their contained protocols, namely the scope of the software application, the end-to-end transport connection, the internetworking range, and lastly the scope of the direct links to other nodes on the local network. Even though the concept is different than in OSI, these layers are nevertheless often compared with the OSI layering scheme in the following way: The Internet Application Layer includes the OSI Application Layer, Presentation Layer, and most of the Session Layer. Its end-to-end Transport Layer includes the graceful close function of the OSI Session Layer as well as the OSI Transport Layer. The internetworking layer (Internet Layer) is a subset of the OSI Network Layer, while the Link Layer includes the OSI Data Link and Physical Layers, as well as parts of OSI\'s Network Layer. These comparisons are based on the original seven-layer protocol model as defined in ISO 7498, rather than refinements in such things as the internal organization of the Network Layer document. The presumably strict consumer/producer layering of OSI as it is usually described does not present contradictions in TCP/IP, as it is permissible that protocol usage does not follow the hierarchy implied in a layered model. Such examples exist in some routing protocols (e.g., OSPF), or in the description of tunneling protocols, which provide a Link Layer for an application, although the tunnel host protocol may well be a Transport or even an Application Layer protocol in its own right. The TCP/IP design generally favors decisions based on simplicity, efficiency and ease of implementation.
dip
on 2010-11-15 10:30:00OSI Model have seven layers, TCP have four. OSI distinguish between service, interface and protocol, where TCP dose\'nt distinguish thm. OSI model description comes first, protocol comes next. TCP protocol comes first and model later. In OSI there is only connection-oriented communication in transport layer and network layer supports both connection oriented and conection less. where as in TCP only connectionless is supported in network layer and both modes in transport layer. Protocol in OSI are better hidden, no Transparency. Protocol in TCP are not hidden and thus cannot be replaced easily.