CommunicationFailed
Final state which means there was a communication failure either when trying to create the payment or when trying to get state updates.
PosLink specifics:
If we got Pending ->CommunicationFailed it means the payment was never created (or for state reason PaymentStateReason.CommunicationFailedNetwork specifically, we may not know if the payment was created or not).
If we got any state other than Pending ->CommunicationFailed it means the updating flow failed unexpectedly. (state reason will be PaymentStateReason.CommunicationFailedUnexpectedly) or PaymentStateReason.CommunicationFailedAuthRequired - in which case you should setup PosLink again after clearing the auth info)