Configuration management is the process that manages the resource configurations. The term “provisioning” is sometimes used interchangeably with CM.
First feature of the configuration managers is to provide abstraction, over the lower layer devices, which leads us to business process consolidation, reduced silos and increased enterprise effectiveness.
Let me give an example on this. Suppose, I have a customer order manager which manages the e2e order-to-cash business process. In a typical scenario, OM will trigger a service activator to activate the service. The SA will then go to the element managers/NEs to configure them, however, for each specific device; there may be different provisioning steps. For example, if the device is Cisco IOS based, you would probably ssh first, enter the password, then enter privileged exec mode, enter the commands. (I remember the times I was using “expect” scripts to achieve this). For another type of device, it could be done by SNMP SET requests. The examples differ. Here, via CMs GUI or NBI, I can issue the same “enable VLAN 1” command and it will be applied to multiple types of devices by the CM.
The second feature of the CMs is configuration tracking. CMs connect to the devices on scheduled intervals and pull the configuration data. They put this data in their repository. This behavior enables us to rollback to a previous configuration in the case of a failure.
CMs also provide user-friendly Diff in order to highlight you which parts of the configuration have been changed.
The third feature is to enforce the policies. Organizations are obligated to conform to specific policies and those should be reflected to the configurations. For example, for a router, disabled telnet access (they want to use ssh) requirement can be implemented on the CM. This case, CM will not allow this request to be passed to the devices, providing a control mechanism.
Individuals may bypass the CM and go and configure the systems directly. This should be considered as an extra-ordinary situation. However, the CMs will also help you to detect discrepancies in the configuration data in their next configuration polling and generate notifications (via trap, email etc.)
We see 3 types of configuration managers in today’s telecommunications environment:
– Server Configuration Managers – manage the servers/PCs. They install OS, install applications, and apply patches.
– Network Configuration Managers – manage firewalls, IPS/IDS, Routers, switches. Their configurations, IOS updates, bulk configurations etc.
– Storage Configuration Managers – manage the storage systems (SAN, NAS etc.)
Most of the devices have element management systems that do the configuration management function, and they are very successful in this. However, these element management systems can only manage specific types of elements. So, if your infrastructure is a multi-vendor environment involving multiple types of devices, investing on a configuration management will definitely bring efficiency to your organization.