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Sem 1 V2 Chapter 2 OSI Model. A ll P eople S eem T o N eed D ata P rocessing. OSI Model Application Layer. OSI Model Presentation Layer. OSI Model Session Layer. OSI Model Transport Layer. OSI Model Network Layer. OSI Model Data Link Layer. OSI Model Physical Layer.
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Although the OSI model is universally recognized, the historical and technical open standard of the Internet is the TCP/IP reference model and the TCP/IP protocol stack. TCP/IP makes data communication between any two computers, anywhere in (or outside of) the world, at nearly the speed of light ,and has historical importance - such as the standards that allowed the telephone, electric, railroad, television, and videotape industries to flourish.
file transport protocol (FTP) hypertext transfer protocol (HTTP) simple mail transport protocol (SMTP) domain name service (DNS) trivial file transport protocol (TFTP).
Differences *TCP/IP combines the presentation and session layer issues into its application layer *TCP/IP combines the OSI data link and physical layers into one layer *TCP/IP appears simpler because it has fewer layers *TCP/IP protocols are the standards around which the Internet developed, so the TCP/IP model gains credibility just because of its protocols. In contrast, no networks are built around specific OSI-related protocols, even though everyone uses the OSI model to guide their thinking. Similarities *both have layers * both have application layers, though they include very different services *both have comparable transport and network layers *packet-switched (not circuit-switched) technology is assumed *networking professionals need to know both
Many networking professionals have different opinions on which model to use. You should become familiar with both. You will use the OSI model as the microscope through which to analyze networks, but you will also use the TCP/IP protocols throughout the CNAP curriculum. Remember that there is a difference between a model (i.e. layers, interfaces, and protocol specifications) and an actual protocol that is used in networking. You will use the OSI model but the TCP/IP protocols. You will focus on TCP as an OSI Layer 4 protocol, IP as an OSI Layer 3 protocol, and Ethernet as a Layer 2 and Layer 1 technology. The END