(FTP), HyperText Transfer Protocol (HTTP), Dynamic Host Configuration Protocol (DHCP), Simple Mail Transfer Protocol (SMTP), Simple Network Management Protocol (SNMP), and several others. Each of these protocols has unique responsibilities (Ogletree 232,233). Like the OSI Model, TCP/IP has layers. TCP/IP contains four layers that loosely correspond to OSI Models seven layers. The four layers of the TCP/IP protocol suite are the Application Layer, the Transport Layer, the Internet Layer, and the Network Interface Layer. The Application layer of TCP/IP corresponds with the Application and Presentation layers of the OSI Model. The Session and Transport layers of OSI Model compare to the Transport Layer of TCP/IP. The Internet Layer of TCP/IP corresponds to the Network Layer, and the Data Link and Physical layers of the OSI Model compare to TCP/IPs Network Interface Layer (Microsoft).IP is part of the Internet layer of TCP/IP. IP is responsible for addressing information and for making sure that data is transferred to where it is supposed to go. IP enables TCP/IP to travel to more than one network segment and more than one type of network. Connecting individual networks can be achieved by the use of a secondary set of addresses called subnet mask addresses (Ogletree 232, 235).The Transport layer of the TCP/IP protocol suite contains the TCP protocol. TCP is responsible for delivering information reliably across a network. TCP requires an established connection between two devices before information can be transmitted. Without TCP, IP would send information without checking to see if the destination devise could receive the data. Also, IP does not ensure delivery. Without TCP, for example, if a computer sends a print job to a network printer, and the printer was not on-line, the computer would assume that the print job succeeded (Dean 68).The subprotocol UDP uses virtual ports to exchange data between two applications on a net...
