Values lock(7), unLock(8) and cancelLocking(9) are dedicated to allow to change critical objects in enabled service. The typical example of critical object is osEthServNodeType. When the value lock(7) is set for unlocked service, the service is cloned. Since then the service is in so called 'locked' state. From that moment, before value unlock(8) is set, all the changes occur only in this clone and the original service remains unchanged and continues to operate as is. When the value unlock(8) is set for the enabled service, the original service is disabled and the clone is enabled. If the clone has been enabled successfully, then the original service is deleted and the clone becomes a regular service. If the clone cannot be enabled, then the message about a reason of it is saved in osEthServLastError, the clone is deleted and all changes in it are discarded. When the value unlock(8) is set for a locked and enabled service, but the clone is disabled, then the original service is disabled and the clone becomes a regular service. When the value cancelLocking(9) is set for locked service, then the clone is deleted and all its changes are discarded. When the service is locked, values delete(3) and lock(7) cannot be set. When the service is unlocked, values unlock(8) or cancelLocking(9) cannot be set. When the service is locked with lock(7), all GET, GETNEXT returns values from the original service. The value erase(10) sets the service into an initial state. This value cannot be set for disabled or locked services.