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In one of our Real-World Labs® at Syracuse University, I tested the second beta release of Hummingbird's JuMP platform in conjunction with HostExplorer Web and Exceed Web X server, both of which were also in beta. The Hummingbird suite promises some compelling benefits for users and system managers alike. Users gain access to legacy host and X-based applications via full-featured clients running in the comfortable confines of a familiar Web browser, while system managers consolidate application delivery and configuration management using JuMP on a centralized Web-based platform. The major catch is that you must use Microsoft Corp.'s Internet Explorer; JuMP does not support Netscape Communications Corp.'s Navigator/Communicator.

Some studies have pegged the Web-to-host market as primed for rapid growth. There's no question that a centralized model such as Hummingbird's has the potential to reduce overall implementation and support costs. But while efficiency is a key element of the management equation, overall effectiveness in meeting user requirements is still the ultimate measure of success. Hummingbird's Web-to-host solution shows great potential in accomplishing both goals, but in the short term you may have to sacrifice a little functionality and flexibility to realize some economy.

Complex Architecture Hummingbird's Web-to-host solution is built around robust client/server industry standards, including a Java development environment, CORBA (Common Object Request Broker Architecture) for interserver object communication, and LDAP for access control and configuration management. The JuMP Web-to-host server, which I tested on NT Server 4.0 with Service Pack 3, handles security and application metering, as well as user-profile management. You can customize applet-launching Web pages according to user and group attributes, so a particular user might only see icons for the hosts or applications he or she needs to access. The Web interface itself is modeled after Windows Explorer, and most users should be comfortable with it after minimal training. Hummingbird's Jconfig utility, which is included in the package, provides the management interface for customizing and controlling access to Hummingbird's thin and fat clients.

Hummingbird's Web-to-host product is compatible with most Web and LDAP version 2.0 and later server platforms. Its reference LDAP server platform is Netscape LDAP Server version 3.11. The vendor includes a simple, internally developed Web server and an LDAP server from Xcert International, which I used during testing.

Terminal emulation and management applications are delivered as Java applets, and Hummingbird has done an excellent job of delivering high-performance, easy-to-use thin clients. Although they do not share a common code base, Hummingbird's HostExplorer, a fat emulation client, and HostExplorer Web share a virtually identical user interface, and both are controlled via the same Java-based management platform. In the lab, I was particularly impressed with the snappy performance of the Java terminal emulation client, which delivered fast screen updates from both IBM mainframe TN3270 and Unix VT-220 environments. Host-Explorer also supports TN5250.

Hummingbird's thin X-server architecture is more complicated than that of the terminal-emulation client, owing to the greater resource requirements associated with X-Windows emulation. The X client Java applet handles video rendering using the power of your desktop system, and an X proxy server handles the bulk of the X-server-to-host protocol. Such a design overcomes performance problems, while minimizing bandwidth usage between the client and proxy server. Although I did not test this capability, Exceed Web includes support for automatic load-balancing across multiple proxy servers. Overall, I found performance to be acceptable for casual usage, but it was not on par with Hummingbird's Exceed for Windows.

Room To Grow While I was fairly impressed with what Hummingbird has accomplished here, I also found a few problems. First, both Exceed Web and HostExplorer Web are only compatible with Microsoft's Internet Explorer 4.0. The vendor decided to forego cross-platform compatibility so it could use Microsoft's Jdirect proprietary graphics interface, as well as the enhanced user-interface characteristics associated with Microsoft's foundation class libraries. At press time, Hummingbird was testing Sun Microsystems' JDK version 1.2 and the results were promising, though still far short of the performance under Internet Explorer. Hummingbird is not the first vendor to wrestle with these Java development trade-offs--nor will it be the last--but the lack of compatibility with Netscape Navigator and earlier versions of Internet Explorer will be a major headache for many sites.

The second major issue relates to performance. While terminal emulation and X-server performance were acceptable during our tests, applet launch time was quite slow--even after Java applets were cached. Many users will perceive this as a step backward in comparison to traditional fat clients. Part of the appeal of the Hummingbird product line is that it gives network managers the ability to deploy thin or fat clients as needed--depending on the requirements of individual users or workgroups--all managed from a common console. Nonetheless, I still think Hummingbird needs to find a way to speed up launch times.

Finally, I encountered intermittent failures when I attempted to access the X-server applets from our servers. Hummingbird was investigating the problem at press time.

Send your comments on this article to Dave Molta at dmolta@nwc.com.