Common Information Model (CIM)

Based on object-oriented technology, CIM a conceptual information model for describing management--and it's supposed to work with all network management approaches. The model is not tied to any particular implementation, and this allows management systems and applications to interchange information without prior knowledge of each other.

In a fully CIM-compliant world, it should be possible to build applications, such as a Service Level Agreement Tracking application, using management data from a variety of sources and different management systems, such as TME, OpenView, ManageWise and SMS. The management data would be collected, stored and analyzed using CIM, while allowing property extensions providing "value add."

CIM originated from the HMMS (Hyper Media Management Schema), which was originally proposed by the WBEM. Due to its origins, CIM is made up of two parts: Schema and Specifications. Eventually, both the CIM Schema and the CIM Specifications will be submitted to the ISO under the Publicly Available Specification process.

The CIM Specification describes the language, naming, Meta Schema and mapping techniques to other management models such as SNMP MIBs, and DMTF MIFs. The Meta Schema is a formal definition of the model; it defines the terms used to express the model and their usage and semantics. The elements of the Meta Schema are Classes, Properties and Methods. The Meta Schema also supports Indications and Associations as types of Classes and References as types of Properties.

The CIM Schema provides the actual model descriptions. It supplies a set of classes with properties and associations that provide a well-understood conceptual framework within which it is possible to organize the available information about the managed environment.

Directory Enabled Networks

In September, 1997, Microsoft and Cisco announced a joint-initiative called DEN (Directory Enabled Networks), which is a specification designed to integrate network hardware with directories such as NDS. Microsoft's own directory service, Active Directory, is still in the works and will also be able to integrate with hardware through DEN. DEN is designed with a standard schema integrating user profiles, applications and network services, which in turn should allow directory services to deliver optimal bandwidth utilization, policy-based management, and a single point of administration for network resources from any location. Shortly after the DEN announcement, experts in the industry began criticizing Microsoft and Cisco for keeping ownership of such a specification. So in March of 1998, both vendors announced their intent to relinquish ownership of the specifications to the DMTF, mainly because the specifications are designed as an extension to CIM (Common Information Model), which is under the control of the DMTF.

However, DEN has sparked a political battle between the DMTF and Microsoft and Cisco. When CIM 2.0 became available, Microsoft and Cisco decided that they wanted to keep DEN compliant with CIM 2.0, and thus they delayed handing over the specifications. Also, a decision was made to consider submissions from companies building their own methods for representing DEN information. This would let vendors, including 3Com Corp., MetaInfo and Novell, open up proprietary schemas for implementing DEN to the DMTF.

Finally on September 28, 1998, a year after the DEN accouchement, the DMTF announced that it officially received the specifications. The DMTF also announced that it will make DEN part of the CIM specification.

DEN shows promise to integrate directory services with hardware in a seamless fashion, but it will be some time before all the political issues are ironed out and real products that use DEN hit the market. Analysts estimate that three to five years will pass before DEN fulfills its potential.

LDAP (Light Weight Directory Access Protocol) is an active participant in this equation, as it has consistently gained momentum in becoming one of the more important directory services protocols. DEN through Microsoft's Active Directory (which Cisco will be implementing for various forms of Unix) will provide access to DNS, NDS and X.500-based directories using either native protocols or LDAP. In addition, Active Directory will support native NT namespaces.

You can find a preview of the specifications on Cisco's site. (http://192.31.7.130/warp/public/734/den/literature.shtml)

The following figure shows how the current specifications envision integration among DEN and the rest of the network.

Conclusions

We can no longer settle for independent scattered computers--networked computers are an integral part of our life. In order to ease remote management of these computers and their respective peripherals, an industrywide management standard must be adopted. And this standard, DMI, exists today thanks to the DMTF. Acceptance of DMI is growing daily: DMI-compliant computers and management applications to control these computers are now widely available. The DMTF is endeavoring to obtain greater acceptance for the standard and to implement improvements. Its latest efforts focus on the Common Information Model, which when fully adopted, will make it even easier for applications to share management information.