I briefly introduced the so-called FCAPS functions in the introduction to this book. I give a little more detail here about this classification of device management.
FCAPS arises from the ITU-T's TMN layering structure and comprises the initial letters of fault, configuration, accounting, performance, and security management:
The detection that a fault has occurred.
The filtering and correlation of the fault reports. In many systems the number of fault reports arising from a single failure can be enormous : if these are not filtered then both the reporting system and the operator can be overwhelmed. Good filtering and correlation allow management systems to grow without becoming unwieldy.
The signalling of root cause to an operator.
The opening of trouble tickets and the management of these (particularly when the fault has occurred in hardware) until the defective component is replaced . However, because most faults occur in software, the replacement of faulty parts is normally not an issue; the failed module can be reloaded and restarted.
Configuration management: allowing the operator to make (or suggest) configuration changes for the device: bring this port up, take that port down, change the IP address associated with this other port. Configuration management also includes the auto-discovery of components and capabilities by the system itself.
Accounting management: collecting and safely storing the information needed to bill customers. This is naturally of prime importance to the device owner and may be surprisingly difficult to provide in many applications ”records may have to be held securely on a device for a long time if contact is lost with the central accounting system.
Performance management: collecting performance information (e.g., number of packets passed per second from a particular port, maximum and mean lengths of packet queues, number of incoming requests handled per second, etc.), compiling and consolidating this into a form that allows a human to identify issues affecting the present and potential performance of the managed devices.
Security management: controlling access to the managed device by users (the people using the device) and operators (the people managing it). Security management includes authenticating users and operators to ensure that they are who they say they are and checking their authority: the level of access they are allowed to the system. Security management may also be involved in protecting the device from malicious denial-of-service attacks.
Another acronym which is sometimes used in conjunction with FCAPS is FAB, fulfillment, assurance, and billing:
Fulfillment (a strange word) covers planning; anticipating the need for additional or reduced capacity and ensuring that it is installed or removed as required.
Assurance covers what would be considered performance, configuration, and fault management in the FCAPS model; i.e., the tasks needed to ensure that customers are getting the services they are paying for.
Billing which covers the collection of payment from the customers for the services they are receiving; i.e., accounting in the FCAPS model.