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Connectivity by Rawn Shah

WBEM and JMAPI on the rise

Emerging standards herald a new era
of network management through the Web

November  1996
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WBEM and JMAPI are two new standards for creating an enterprise-level network management infrastructure. Based upon the World Wide Web, they create a new interface for management which simplifies the usage of tools as well as fixing holes in current standards and schemes. (1,900 words)

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It wasn't too long ago that Web-Based Enterprise Management meant that one "wunderbar" programmer had hacked together a Perl script that could access remote system information and display it on a screen. I know this from first-hand experience.

Now it seems that using your Web browser to view and administer your network might become commonplace. After all, the browser is simply a generic interface, and systems like CGI scripts, Java, ActiveX, etc. provide the enhancement that greatly increases the usefulness of this tool.

In recent months, two camps have talked of creating a formal system for managing all network systems through the Web. Microsoft, Compaq, Cisco, Intel, and BMC Software proposed "Web Based Enterprise Management" (WBEM). WBEM enjoys a larger supporting cast of vendors including Netscape, Acer, Dell, Wall Data, Zenith, Tandem, 3Com, Hewlett-Packard, Digital Equipment Corp., NetFrame, Oracle, and Computer Associates.

The other camp consists of some of the same vendors -- Cisco, BMC, and 3Com, as well as Bay Networks, Novell and several others -- led by Sun Microsystems. This effort is based on Java and is known as the Java Management API, or JMAPI.

It is important to look at the concept of managing your enterprise through the Web and examine how these two proposals are structured and how they function. First, no matter what other pundits say, WBEM and JMAPI are not direct competitors. This is not "Java vs. ActiveX, round two." Although they overlap in some areas, there are differing philosophies in each. There might even be ways they will work together -- at least that's what major proponents like 3Com and Cisco hope.

Browsing your network
The implication that you can access your network components through the Web makes people fear that vendors might stick Web servers in every tiny little component, add them to the network, and create additional traffic. Not entirely true. Although you use HTTP to access Web servers, this protocol isn't built for everything. In fact, it is very limited, as many have pointed out.

One concept to test is creating another protocol to communicate with managed devices through your browser. For example, you could set up tiny Web servers on each of the managed devices that browsers could query directly. You could also create special Web browsers that can send and receive SNMP or RMON requests and responses.

Another method is to create an interface plug-in or application for a Web browser that acts as the intermediary. This application will convert a request for an access into something that a managed device might understand, such as an SNMP GET attribute. This way, you do not need to add HTTP capabilities to your managed devices, which could get quite complicated and insecure.

This interface level might work in several ways. You could have Web-to-database connection where all the data from your managed devices are stored in the database. This data is then accessed as a client through the Web browser. You could also create a CGI script that communicates with the device and then outputs the information to your Web browser upon request. Another possiblity is to let a Java or ActiveX applet perform the same task. Basically, the differences between each of these methods are where the processing occurs, and the capabilities of the browsers. WBEM is based upon the first concept (modify the brower) while JMAPI leans more towards the second (create a browser plug-in).


WBEM is a proposal for a new type of management architecture known as HMMA, the HyperMedia Management Architecture. HMMA consists of two parts, the schema and the protocol. The HyperMedia Management Schema (HMMS), is a design of how managed objects are structured and how they are interrelated. The HyperMedia Management Protocol (HMMP) is a communications protocol that is effectively SNMP running over HTTP. HMMP can also be structured to function with other management protocols, such as the Desktop Management Interface (DMI), which is the network management protocols for desktop PCs created by the Desktop Management Task Force.

HMMS is an object-oriented model for management. Objects within this schema have relationships and inheritance of properties according to the class of managed devices to which they belong. As in many object systems, they communicate by sending events amongst themselves. One common event is a request for information from a browser directed at a managed device. Other events like alarms and notifications also exist. Each managed device is an instance of a class of objects and is designated a HyperMedia Management Object (HMMO).

WBEM structures a new "language" inside of HTML for creating events and communicating with these devices. The scripting command structure for HMMS is stored within HTML Comment tags. For example, the figure below shows the structure of what WBEM code looks like within an HTML document:

<HEAD> <TITLE>Logical Disk</TITLE></HEAD>

<!--{[UniversalKey]Name}--> C: <!--{[]}-->

<p>Available Space
<!--{[Integer]AvaliableSpace}--> 102 <!--{[]}--> k Bytes

<!--{[Integer]Size}--> 1000 <!--{[]}--> k Bytes

<!--{[Ref]DrivePartition}--> <A HREF"Object2.htm">
<!--{[]}-->Drive Partition </A>


The code <!--{[UniversalKey]Name}--> is an message telling the device to enter its unique name. Similarly you can see other directives within the comments of this example. The very last line of the example is a list of indices to a universal table of HMMOs identifying where you can get a full description of the object itself. The browser needs to be configured to point to a server which holds this data and table.

As you read the definition document, you'll agree the HMMA standard is quite complex. It creates a new language and object-oriented structure designed specifically for this purpose. As object-oriented languages and systems go, you notice it is a full specification with sophisticated traits such as inheritance, polymorphism, associations, etc.

The group of well-known vendors which met in July for the first draft of the specification have participated in other standards efforts. A reference version written in C++, known as the HyperMedia Object Manager, will be the first implementation of HMMA.

JMAPI is a programming API describing how to create a network management application. Unlike WBEM, there are no new protocols or schema involved. Managed devices still communicate using common standards such as SNMP and RMON.

What JMAPI does is provide the framework on how to create Java-based applets and applications for network management. One of the inherent problems with products based upon SNMP such as HP OpenView, IBM NetView, and Sun Solstice Enterprise Manager (the current 2.0 and older versions), is that although the protocol for communicating with these network devices is the same, the framework and architecture of these applications are different. You cannot, therefore, take portions of OpenView you like and move them to a different interface like Solstice Manager. Sun's Java push towards a unified and platform-independent architecture promotes exchange of objects easily. The theory is that a new network management framework created with JMAPI will provide this ability.

Who's on first?
With potential standards, it is always difficult to know which will survive. Large companies like Cisco and 3Com can afford to be in both camps and develop for both sides. However, small vendors cannot put up the large capital to support both, and they are forced to choose sides.

The question of picking sides is a hairy one. Both sides have an equal number of supporting vendors. Both sides also have the support of industry leaders in the management and networking markets. It is easy to assume Sun will continue to promote JMAPI as long as Java is a worthwhile technology. Meanwhile the other top vendor, Microsoft, has a lot of investment in its own embryonic management effort. It is hard to make a business case for which is the better standard, though I have noticed more problems surrounding WBEM.

The first question I have about WBEM is, why reinvent the wheel when it comes to object-oriented environments? Java is already there, why make a new object hierarchy and design a new language all over again? A second question is, why do we need to bastardize the HTML Comment tags even more? Vendors who want to make their own proprietary tags or features for their Web browsers have typically stuck them inside HTML comment tags. Comment tags contain just comments about the surrounding HTML, not programming languages. It's an easy out for many vendors. Another question: Why create a new protocol for managing network devices? We already have SNMP and RMON. Although they are not the be-all-end-all of network management architectures, there is already a huge investment in them. HMMS does make use of SNMP, but pushes it into a different network level as well.

WBEM for some reason seems to be a standard made by huge committee -- not the best way for creating a standard. It also seems like it was created to specifically ignore a good many elements of current network management, Web, and de-facto standards.

JMAPI isn't without fault either. One of the things that concerns me about Java is that it is created by one vendor. There's definitely a lot of input from others, but control of the many APIs is still in the hands of JavaSoft. There is simply a lack of democracy. Technologically, however, JMAPI is sound and doesn't reinvent any wheels.

Since both are only a few months old and haven't even been released as official standards yet, it is hard to tell which one will come out on top. The matter is complicated by leaders like Cisco and 3Com who are taking part in both standards. We'll have to see what is accepted by the masses over the next year. It's called standards implementation through popularity.

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About the author
Rawn Shah is vice president of RTD Systems & Networking Inc., a Tucson, AZ-based network consultancy and integrator. Reach Rawn at

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