fferent places. All the user sees is the completed screen with the appropriate results intended by the owner of the Web page. This, of course, is the reason the screen may fill in at the receiving end in very erratic pat- terns. As IP delivers the datagrams, TCP determines that it has the file and delivers the information to the terminal or PC. Therefore, as the data arrives from different locations on different routes, the information may appear to be somewhat disjoined. In reality, it is not. Transmission Control Protocol/Internet Protocol (TCP/IP) TCP and IP were developed by a U.S. DOD research project to connect a number of networks designed by different vendors. It was successful Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2004 The McGraw-Hill Companies. All rights reserved. Any use is subject to the Terms of Use as given at the website. X.25, Internets, Intranets, and Extranets X.25, Internets, Intranets, and Extranets because it delivered a few basic services that everyone needs (file transfer, electronic mail, and remote logon). Several computers in a small depart- ment can use TCP/IP on a single LAN. The IP component provides routing from the department to the enterprise network, then to regional networks, and finally to the global Internet. As with all other communications protocols, TCP/IP is composed of lay- ers, which are shown in Figure 7-15. This representation is significantly dif- ferent because it shows the various other protocols that can be contrasted in wired and wireless networks: IP Responsible for moving datagrams (commonly referred to as packets) from node to node. IP forwards each datagram based on a four-byte address. The GPRS networks were primarily set up to handle IP routing and switching from a mobile station at higher speeds than were previously available. The Internet authorities assign a range of numbers to different organizations. These organizations assign groups of their numbers to departments. IP operates on gatew