The newest business-computing revolution is network computing. Network computing is sometimes even referred to as the next generation of client/server computing. I believe (my personal biases are showing) that network computing will have a bigger impact on business computing than the PC revolution did. The network technologies already have changed the way we live and work. The Internet, and especially the advent of the Web (officially called the World Wide Web) in 1993, are making information into a utility similar to electricity or telephone service. Geographical boundaries have disappeared overnight as we all have gained access to a worldwide network of computers. Whole communities in cyberspace have evolved, where people of like interests can get together to communicate and interact through chat rooms and discussion forums. This colonization of cyberspace provides new opportunities for businesses to target specific groups of potential customers they previously could not reach.

Clearly, the consumer market is driving the early movement to network computing, but the opportunity for other businesses is enormous. Businesses can gain huge competitive advantages from network computing by working more closely with customers and with other businesses over the Internet. As businesses begin to appreciate the Internet, many of them are recognizing the benefits within their own businesses and are implementing intranets (an intranet uses the technologies of the Internet on a private network that can be either local or enterprise-wide). All of this helps to explain why more and more these days, business is becoming e-business.

Implementing the Standards

The good news about network computing is that it is based on standards. The only way to connect a worldwide network of dissimilar computers is to adopt a fairly small set of standards and implement them everywhere. The AS/400 is a full Internet server with all the standards necessary to do Web serving.

Figure 11.2 shows the various offerings available on the AS/400, together with the standards these components support. IBM first introduced Internet Connection in 1996 as a part of TCP/IP Connectivity Utilities in OS/400 and will continue to enhance the software at each release of Version 4.

Figure 11.2  AS/400 Internet Connection

When I discussed secure Web serving in Chapter 7, I introduced many of the acronyms in Figure 11.2 and provided a brief description of the function they provide. I repeat some of those here. My intent behind the following discussion is to show the breadth of function available on the AS/400 for Internet and intranet serving, not to describe every component in detail. It is important to note that new applications, as well as existing applications, are enabled to participate in the network world.

Any Mail, the offering that gives the AS/400 its mail-serving capabilities, supports several standards. The Simple Mail Transfer Protocol (SMTP) function allows electronic mail to be sent or received. The AS/400 also can function as a Post Office Protocol (POP) server. A POP server provides a mail box, where the mail can be stored until the recipient opens it. POP3 is the latest version of this standard. The Internet Message Access Protocol (IMAP) provides synchronization of local data across multiple Internet nodes (for example, a machine at work and a machine at home), so the complete mail environment can float from machine to machine. Multipurpose Internet Messaging Extensions (MIME) is the Internet standard for sending mail with headers that describe the contents of the mail message to the receiving client. These messages can be video, image, audio, text, or binary files. Secure Multipurpose Internet Messaging Extensions (SMIME) is the secure form of MIME.

Web clients can access existing 5250 applications through Telnet, which provides terminal emulation for 3270, 5250, and VT100 terminals across the network, or through the Hypertext Markup Language (HTML) Gateway. HTML is the datastream between the Web server and a Web browser on a client in the network. HTML Gateway provides a way to graphically view 5250 applications through a browser.

The Internet’s standard transport protocol, called the Hypertext Transport Protocol (HTTP), is used by the Internet Connection Server and the Internet Connection Secure Server to communicate with Web clients. The difference between these two HTTP servers is that one is non-secured and the other is secured. The selection of which one to use depends on business needs, as I discuss shortly.

You can access the Integrated File System (IFS), which supports files containing HTML and Java, using several protocols. The most common protocols are HTTP and the File Transport Protocol (FTP). Figure 11.2 shows the servers for these two protocols. Servers are also provided for other protocols. These other protocol servers include BootP (BootStrap Protocol) server, TFTP (Trivial FTP) server, Telnet server, and RIP (Routing Information Protocol) server.

Common Gateway Interface (CGI) is a standard Web server protocol that lets server-based programs interact directly with a Web browser on a network client. The standard way that all other servers deliver network applications is via CGI applications. CGI applications also are fully supported on the AS/400. Finally, an alternative to writing CGI programs that simplifies access to DB2/400 from the Web is through the Net.Data macro processor.

The Transmission Control Protocol/Internet Protocol (TCP/IP) is the industry-standard transport mechanism used across the Internet. The physical connections can be via leased lines, asynchronous dial-up lines, and LANs. For dial-up connection to the Internet, you can use either of two protocols: Serial Link Internet Protocol (SLIP), or point-to-point protocol (PPP). LAN connections can be Token-Ring, Ethernet with communications up to 100 Mb per second, wireless, or the new Asynchronous Transfer Mode (ATM) for communications up to 155 Mb per second.

Security on the Internet is critically important. This is especially true when you are conducting commercial business on the Internet. Network security enhancements continue to be added to the AS/400 either as part of the base support included with OS/400 or as separate products. For example, HTTP basic authentication is part of the base support. Basic authentication prompts the user for a user ID and password when a client tries to access a restricted Web page. In this way, the AS/400 user profiles or a separate server’s user validation list can be used to restrict access to Web pages at the user level.