A network generally comprises equipments to be managed and a device for managing those equipments.
Network management is based on the management device and the equipments to be managed exchanging information. Thus the management device can send commands to one or more network equipments, in particular to request modification of configuration parameters, or merely to consult certain configuration parameters of the network equipments. The network equipments prompted in this way generally modify the parameters on receiving a modification request or send requested information on receiving an information request. The network equipments are also adapted to send information spontaneously to the management device, such as in particular information relating to alarms.
The data exchanged in this way must be comprehensible to the sender and to the receiver. To this end, a network conventionally uses a management information base (MIB) reference model of such management information.
An MIB specifies a management information model in the form of objects to be managed in relation to parameters to be consulted, parameters to be modified, or alarms to be sent. These objects are specified by the International Standardization Organization (ISO) in the form of an object record tree. Thus a reference is assigned to each object specified in the MIB.
As a function of the type of management required, it is possible to refer to only a portion of the MIB tree, below called the “MIB portion”.
The MIB contains individual scalar objects that can be instantiated once only, and groups of objects that can be instantiated a varying number of times, these groups being conventionally represented in the form of tables in which each row represents one instance of the group of objects. Each row is then identified by an index.
In a management network, the equipments and the management device generally know the MIB portion in accordance with which they manage their own management data. Thus a network is conventionally managed on the basis of a model of the above type, with knowledge thereof being shared by the management device and the network equipments to be managed.
A standardized protocol such as the simple network management protocol (SNMP) is generally used to send this information between the equipments and the management device. This kind of protocol is suited to exchanging management data relating to objects specified in the MIB, but it occupies considerable transmission bandwidth in the network. About 75% of the size of each message corresponds to ‘Abstract Syntax Notation 1’/‘Basic encoding rule’ (ASN.1/BER) references.