Data Collection Protocols: CMISE/CMIP and GDMO

The fundamental function of the Common Management Information Service Element (CMISE) is the exchange of management information between manager and agent entities.

CMISE is specified in two parts:

• The Common Management Information Service (CMIS) is a user interface specifying the services provided (ISO 9595).

• The Common Management Information Protocol (CMIP) specifies the Protocol Data Unit (PDU) format and associated procedures (IOS 9596).

CMIP was proposed as a replacement for SNMP as part of the ITU-T Telecommunications Management Network (TMN). The major advantages of CMIP over SNMP are as follows:

• CMIP variables contain information similar to SNMP and can also define actions and perform tasks.

• CMIP has built-in security mechanisms for authorization, access control, and security logs.

• CMIP provides flexible reporting of unusual network conditions.

• The CMIP information model is object-oriented compared to the object-based model from SNMP.

Guideline for Definition of Managed Objects (GDMO) provides a language for defining managed objects within TMN-based systems. GDMO is a structured description language for specifying object classes and the objects' behaviors, attributes, and class ancestry. While there is an analogy to the SNMP Structures of Managed Information (SMI), the GDMO format is not derived from Abstract Syntax Notation 1 (ASN.1).

Although the "S" for Simple in the SNMP acronym reflects the philosophy behind the SNMP protocol design, CMIP/CMIS was designed to be much more powerful and therefore is more complex and resource-intensive to implement. This, along with some performance issues, explains why CMIP/CMIS were not widely adopted throughout the industry. In the competition between the IETF SNMP and the OSI CMIP, the industry clearly selected SNMP as the winner because of quick developments and freely accessible standards. Although this section is interesting from a reference and quick overview point of view, the authors advise you not to investigate CMISE, CMIP, and GDMO further.