There are two major parties involved into management "game":
| • | Managed party -- a network to be managed, consisting of a multitude of interconnected devices, services and applications (network elements/items/nodes). A device is a network element with assigned IP address. Another term that can be used as a synonym is network or IP host. Device provides functionality in terms of services/applications it is running. Manageable device can be any type of device, including, but not limited to, routers, access servers, switches, bridges, hubs, IP telephones, IP video cameras, computer hosts, printers. Examples of services and applications are Web services, e-mail services, database management systems, etc. One of the most important services, we expect to be provided by network device, is ICMP ping. Another important type of service a device can provide for manager is SNMP support. AggreGate Network Manager supports many other types of services and applications as covered in Application/Service Monitoring section. |
| • | Managing party -- people performing the management, and tools (management system) used to accomplish management tasks. AggreGate Network Manager is an example of such a management system. |
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There is another part that can't be easily classified here: common media providing communication between the two parties. Ironically, the media conforms to both definitions above: as a part of network it is subjected to management and hence is a managed party; but, on the other hand, as a facility providing execution of management tasks it can be treated as a part of managing party. We don't go deeper into the speculations here and confine ourself by stating the fact that a distinct classification here could be somewhat sophisticated. The subsequent reasoning if left for our readers. |
Extending the management terminology here, we introduce terms Manager and Agent.
Manager can be any kind of management system that performs its duties by tracking and controlling activities of network items. The variety of possible functionality that manager can provide and architecture it can be built with is endless. Manager role can be played by a simple network utility, a very specific application or a huge and sophisticated network management system. Therefore it's impossible to provide any reasonable description for structure or functionality of manager here.
Management agent represents a separate network element that is a network device, service or application. As a network element, agent has some essential functionality referred here as its core logic. Additionally agent provides some kind of management interface that makes it available for management and provides information about network element that can be consumed by managers. Thus, an agent can be represented as a three-part component: core logic, management interface, management information base (MIB).
Core Logic
Here we use the term Core Logic to refer to essential functionality of network item. This may include operations the item provides, algorithms, parts it comprises and relations between them, etc.
Management Interface
Management Interface provides interaction between agent and manager, providing execution of manager requests and commands, sending back the data requested, and altering the element configuration if needed.
Management interface can be implemented as a dedicated interface existing exclusively for and performing only management tasks. Examples are ICMP and SNMP services. But other types of interfaces can be also used to monitor and control certain aspects of a network element. For example, availability and operability of many services and applications can be monitored by accessing and using their core functionality. Say, we can check an e-mail system operability by connecting and communicating with the service via a certain protocol (POP3/IMAP/SMTP). Furthermore, we can ensure that the e-mail system operates properly in whole by sending a test message and checking its delivery to recipient.
Management Information Base (MIB) presents pieces of management information about network item, offering an abstraction of the manageable item used for management purposes.
All the management information concerning a particular network item can be regarded as a (virtual) data store that comprises description of all the entity's physical and logical aspects. The data may cover monitoring information, for example, hardware configuration (e.g. available ports and line cards), current state and characteristics; as well as configuration settings that allow manager to control item activity.
The MIBs are not real databases; they just reflect information from network item's core. Note, that often MIBs present snapshots of data obtained from core at some instant, and MIB contents is refreshed periodically. The update periods and communication delays should be taken into account by management operations.
There are plenty ways management information can be represented and exchanged between agents and managers. One of the most common standards for that, and the one supported out-of-box by AggreGate Network Manager, is SNMP. Refer to SNMP Management section for details about SNMP, what for and how it can be used in AggreGate Network Manager.