Clients may have redundant multiplexer's (Mux) at their ISP end and expect an alarm in OneClick when any of the Mux at ISP end goes down.
Something like the below connection:
Router1 -> L2 Switch -> Mux -> WAN Link -> Mux -> L2 Switch -> Router2.
If there is only one Mux at the ISP end and if it goes down, the other end router will not be reachable indicating that something has gone wrong at ISP end. In the topology if there is a redundant Mux the other end router will be reachable even if the primary Mux goes down. In this case we may not have a proper root cause as the Mux from the ISP cannot be discovered in Spectrum as a model to alarm on it. This problem can be solved by representing the Mux as a WAN Segment model and using Condition Correlation Editor.
BGP is a requirement and must be enabled on the end routers connected to the WAN Link so that in the event of an outage we get a BGP peer session lost alarm on the end router interface connected to ISP when the primary Mux goes down.
Create a WAN Segment for the Mux model using the below process in OC and connect this WAN Segment to both ends of the router interfaces which are connected to the WAN Link.
To manually create a WAN Link between two end devices: