 : n etconf: base : 1.0" > <rpc-error> <error-type>RPC Connection</error-type> <error-tag>Device not found</error-tag> kerror-severity>Major</error-severity> <error-info> <!-- Details of the error --> </error-info> </rpc-error> </rpc-reply> The request and reply both include the same message-id number. In case of an error, the rpc-error is encapsulated in the rpc-reply. The NETCONF reply can Fundamentals of EMS, NMS and OSS/BSS indicate one or more errors of varying severity. The error message is mapped to a specific type, along with severity to identify how quick a corrective action is required, and other error-specific details that will help debugging the error. It can be seen from the example that the error response can be easily parsed and valuable information displayed in any format that is required for a GUI or Web-based appli- cation. In an event driven network management system, the contents of the error could be programmed to trigger events that involves corrective actions. In addition to the usual configuration management protocols that provide cre- ate, edit, and delete capability, NETCONF has many other commands that help the operations team to easily manage configuration. Some of these include the merge command used to merge the configuration data at the corresponding level in the configuration datastore and replace command used to replace the configuration data in the datastore with the parameter specified. Another very useful command in NETCONF is lock, which can be used by the management system to ensure exclusive access to a collection of devices by locking and reconfiguring each device. Only when required will the changes be committed. This provides an environment where multiple system administrators and their tools can work concurrently on the same network without making conflicting changes to configuration data. NETCONF offers sophisticated configuration capabilities where a device con- figuration can be changed without affecting its current configuration. The configu- ration changes can be ma