A network node (1 5), comprising: at least one communication interface (3 1-2); at least one memory; and at least one processor configured: - to receive an interest message on said at least one communication interface (3 1) from a downstream node (1 4), said interest message comprising a name of a requested data object, - to determine whether to bid for storing said requested data object in said at least one memory, - to calculate a bid value, - to forward said interest message to an upstream node (1 6) on said at least one communication interface (3 2), the forwarded interest message including said calculated bid value in dependence on at least said determination whether to bid, - to receive a data message comprising said requested data object from said upstream node (1 6) on said at least one communication interface (3 2), - to determine from at least said data message whether said network node (1 5) won said bid, - to store said data object in said at least one memory if said network node (1 5) won said bid, and - to forward said data message to said downstream node (1 4) on said at least one communication interface (3 1). at least one communication interface (3 1-2); at least one memory; and at least one processor configured: - to receive an interest message on said at least one communication interface (3 1) from a downstream node (1 4), said interest message comprising a name of a requested data object, - to determine whether to bid for storing said requested data object in said at least one memory, - to calculate a bid value, - to forward said interest message to an upstream node (1 6) on said at least one communication interface (3 2), the forwarded interest message including said calculated bid value in dependence on at least said determination whether to bid, - to receive a data message comprising said requested data object from said upstream node (1 6) on said at least one communication interface (3 2), - to determine from at least said data message whether said network node (1 5) won said bid, - to store said data object in said at least one memory if said network node (1 5) won said bid, and - to forward said data message to said downstream node (1 4) on said at least one communication interface (3 1). - to receive an interest message on said at least one communication interface (3 1) from a downstream node (1 4), said interest message comprising a name of a requested data object, - to determine whether to bid for storing said requested data object in said at least one memory, - to calculate a bid value, - to forward said interest message to an upstream node (1 6) on said at least one communication interface (3 2), the forwarded interest message including said calculated bid value in dependence on at least said determination whether to bid, - to receive a data message comprising said requested data object from said upstream node (1 6) on said at least one communication interface (3 2), - to determine from at least said data message whether said network node (1 5) won said bid, - to store said data object in said at least one memory if said network node (1 5) won said bid, and - to forward said data message to said downstream node (1 4) on said at least one communication interface (3 1).