In the case there has been an interruption (for example: connectivity lost, or the subscription has been paused by the provider), is expected that the consumer invokes the subscription interface to resume the subscription and start getting updates again, after the connection to the queue is re-established.
To ensure that updates since the last time the system was known to be working properly are not lost, is expected that the consumer invokes the retrieval interface specifying the time since when recovery is required.