TCP/IP AND THE FUTURE OF THE INTERNET OVER WIRELESS MEDIUM Fifteen Years ago computers were just an expensive typewriter, calculator, and entertainment center thrown together in one box. People transferred their tiny files with floppy disk. The computer itself seldom had a hard drive. It was an amazing feat to dial into a computer bulletin board, and talk to other users of systems. Networking computers was more or less unheard of. The only exception were mainframes that might span several buildings, with terminals, or dial in terminals. The internet, and TCP/IP were developed by the Department of Defense so as to be able to link together several LANs around the country. Each individual system was built sometimes by different vendors, and were sometimes incompatible. For example I can remember my father telling me while he was working at Perkin Elmer that they had to link from San Diego to Cheyenne Mountain in Colorado with two dissimilar systems. TCP/IP was a robust common language that could be used. In part the same is true today, The Arpanet is no longer the driving factor in the internet, but business. Computers using a myriad of operating systems, from a DEC to a Unix box, to someone running Windows 2000, they all can speak the same language. Beken 2I’m going to overview how TCP/IP works into the entire system. Keeping in mind the OSI reference model (Fig. 1). While TCP and/or UDP are running at the Transport Layer IP is running at the Session Layer. The IP protocol handles fragmentation of packets. Fragmentationis essential, because some networks allow a verylarge packet size, and others do not packets sometimes must be fragmented. The presentationlayer is where the TCP/IP “languages” are usedsuch as FTP, SMTP, HTTP, and Gopher. Fig. 2 demonstrates the overlapping of the Ethernet Frame, the IP packet, and TCP packet. (Fig. 1) 7 layers of the OSI ModelThe ...
