CommunicationStatus indicates the ability of the instrumentation to communicate with the underlying ManagedElement. CommunicationStatus ...

CommunicationStatus indicates the ability of the instrumentation to communicate with the underlying ManagedElement. CommunicationStatus consists of one of the following values: Unknown, None, Communication OK, Lost Communication, or No Contact. 
A Null return indicates the implementation (provider) does not implement this property. 
"Unknown" indicates the implementation is in general capable of returning this property, but is unable to do so at this time. 
"Not Available" indicates that the implementation (provider) is capable of returning a value for this property, but not ever for this particular piece of hardware/software or the property is intentionally not used because it adds no meaningful information (as in the case of a property that is intended to add additional info to another property). 
"Communication OK " indicates communication is established with the element, but does not convey any quality of service. 
"No Contact" indicates that the monitoring system has knowledge of this element, but has never been able to establish communications with it. 
"Lost Communication" indicates that the Managed Element is known to exist and has been contacted successfully in the past, but is currently unreachable.