Monitoring Support for LTE Links on Dual CPEs

In single CPE deployments, when an LTE link goes down a critical alarm is generated. This behavior remains the same in dual CPE deployments if the LTE Mini-PIM is installed in only one node.

In dual CPE deployments with the LTE Mini-PIM installed in both the nodes, the Mini-PIMs operate in active / backup mode. By default, the LTE links are non-revertive—when a preferred active link goes down and the backup link becomes the active link, the backup link continues to be the active link until it fails. The preferred active link does not become the active link until the current active link fails. For example, consider a dual CPE deployment in which the LTE link on node 0 is active. If the LTE link on node 0 fails, then the LTE link on node 1 becomes the active link. Now, even if the LTE link on node 0 becomes operational after some time, it does not become the preferred active link. The link on node 1 continues to be the active link until it fails, at which point the node 0 link becomes the active link again.

When both the LTE links fail, CSO generates a critical alarm. If you configured the node 0 LTE link as the preferred link (active link) and node 1 LTE link becomes active, CSO generates a major alarm to indicate that the user preference is node 0 but the active LTE link is on node 1. If the link on node 0 becomes operational again, it does not automatically become the active link. As a result, CSO does not clear the alarm until the preferred link becomes active again.