After the network element is synchronized successfully, the service port status is still inconsistent with that of the host computer. But after the successful single synchronization of the service port, status of the service port is consistent with that of the host computer.
Why the service port status is still inconsistent with the host after synchronizing the network element in the topology structure?
When the network element is synchronized, the NMS requires synchronizing the pvc module. Since synchronization of the network element requires more time, to save time of network element synchronization, the NMS compares the serial number and checks whether the NMS data is consistent with that of the host. If consistent, synchronization is not needed.
Only when the serial number of the host is larger than that of the NMS, the NMS can read data from the host (send the getall command to the host) and poll the pvc module actually; then, update the serial number of the NMS to keep consistent with the host. Otherwise, the NMS will regard its data as consistent with the host (not send the getall command to the host) and return directly. If the service port status cannot be synchronized, that indicates that the serial number of the host is equal to that of the NMS.
Moreover, as for manually polling to the pvc module, no need to compare the serial numbers since the user determines synchronization and read data from the host (deliver the getall command to the host). Therefore, the service port status can be synchronized.
Considering the efficiency of synchronizing the network elements, the NMS compares the serial number when synchronizing the network elements. Because of the large amount of data and modules during synchronization, and that some data of modules may be consistent with that of the host, the data is no longer required to be read from the host. Thus, the efficiency of the network element synchronization can be improved through serial number comparison, and time is saved.