In-Depth
Web to Host Connections: The Great Outward Migration Commences
There used to be two places in the world where everyone knew your name – "Cheers" in Boston, and the central IT department. Just as everyone knew the exact stool where they could reach Norm, everyone in the organization knew where to reach you when they had trouble logging onto your S/390 mainframe host system from their PC.
However, this personable environment is ending, as mainframes garner more end users. That’s because tens of thousands of end users may be coming from outside your SNA network, and even your organization. You won’t even have a clue about what kind of computer they are using as a client, and they won’t have a clue as to what kind of host system they are accessing.
In fact, within a few years, well over half of end users accessing mainframe hosts will be external, browser-based users – in "outward-facing networks," predicts Richard Villars, Director of Network Architectures for IDC (Framingham, Mass.). The installed base of traditional internal PC-based host access users peaked last year, he notes, with Web-based connectivity solutions beginning to win market leadership.
The result is the most monumental sea change in host access since its inception more than a decade ago.
The most dramatic change is the expansion of host connectivity to users on the Web, making mainframe host data accessible through browsers. Users anywhere in the world – remote employees, sales representatives, business partners, vendors and customers – can log on and view a Web presentation of host data as an HTML rendition through their browser, or through a Java applet running as a terminal emulator, downloaded as needed. IDC’s Villars believes such configurations will become tightly integrated with broader e-commerce initiatives, and present a means for online customers to access data.
Often, the potential for Web-to-host connectivity gets lost between the conflicting demands of IT managers and business managers. One area of an organization may be connected via host access, while the other is pouring resources into its intranet – and neither side wants to meet in the middle. As a recent report from Aberdeen Group Inc. (Boston) puts it, host access is an approach that is "not well understood or documented, making it difficult for organizations to align themselves internally around a unified position." In fact, Aberdeen finds Web-to-host issues are the source of inter-departmental stress.
That’s a shame, because Aberdeen estimates that up to 70 percent of all critical business logic and data resides in host-based applications – a real competitive gold mine. The imperative is to get mainframe-based data out beyond the firewalls, to extranets of customers, suppliers and business partners. Those managers that are now all fired up over extranets and e-commerce need to become acquainted with the ways host data can be securely presented.
The best approach to a migration from green-screen terminals to a TCP/IP-enabled environment is a stepped migration, which maintains the existing network while building outward to the Web. The first step is to migrate internal users to 32-bit desktops, running 32-bit emulators, which can be connected to the existing SNA network. The next step is to introduce TCP/IP connectivity, which can be auto-detected and accessed by the new desktop emulators. Follow up with Java-based green-screen emulation, through a host screen downloaded at the beginning of a Web session.
While traditional PC-based host access technology is mature – and very robust in terms of management and security – Web-to-host solutions are still in their formative stages. In fact, the Internet adds a new security and management burden – currently the most pressing concerns in delivering access over the Web.
Web-to-host based systems can deliver legacy applications over any TCP/IP network, without the need to re-engineer or replace these back-end applications. However, since it’s so new, Web-to-host access still faces a number of hurdles before it’s on a par with PC-to-host connectivity in terms of functionality.
Maintaining uptime and accessibility is also a challenge over the Internet, and file transfers over the Web will need to be addressed as well. Users will seek the same capabilities and security in Web-based environments that are now part of traditional client/server environments.
Keyboard systems tend to disappear when converted to a browser format. Those systems that do maintain 3270-based keyboard functions may befuddle external users not experienced with mainframe terminals. Thus, 3270-style interfaces may be fine for the internal group that’s used to it, but a much simpler interface needs to be presented to outsiders.
Due to real and perceived concerns about the security and reliability of Web connections, direct dial-up arrangements may still be the favored means to reach corporate remote end users and business partners for some time. But it won’t be long before Web-to-host becomes part of the strategy of organizations seeking to extend the power of their mainframes to a larger audience.