In one embodiment, a managed cache system, includes a cache memory to receive storage units via an uplink from a transmitting client, each storage unit including a decodable video unit, each storage unit having a priority, and enable downloading of the storage units via a plurality of downlinks to receiving clients, and a controller processor to purge the cache memory of one of the storage units when all of the following conditions are satisfied: the one storage unit is not being downloaded to any of the receiving clients, the one storage unit is not currently subject to a purging exclusion, and another one of the storage units now residing in the cache, having a higher priority than the priority of the one storage unit, arrived in the cache after the one storage unit. Related apparatus and methods are also described.