A request router for a multi-tier Content Delivery Network, CDN, each tier corresponding to a hierarchical layer of the CDN, the request router comprising processing circuitry configured to: receive, from a first delivery node of a hierarchical layer of the CDN, a routing request to bypass the first delivery node for content delivery to a user equipment, wherein the routing request comprises at least a bypass ratio and an Internet Protocol, IP, address of the user equipment, and wherein the bypass ratio is a ratio of a number of content delivery requests that should bypass the first delivery node to a total number of content delivery requests assigned to the first delivery node and the bypass ratio is determined based on at least a processing load of the first delivery node; as a result of receiving the routing request to bypass the first delivery node for the content delivery to the user equipment, select at least a second delivery node (14b, 14c) for the content delivery to the user equipment, wherein the processing circuitry is further configured to select the at least second delivery node (14b, 14c) for the content delivery to the user equipment from one of a same hierarchical layer of the CDN as the hierarchical layer of the first delivery node and/or a higher hierarchical layer than the hierarchical layer of the first delivery node, the selection being dependent on at least a number of delivery nodes in the CDN that are determined to be in a bypass mode, and wherein the bypass mode is one of input/output protection modes for a plurality of delivery nodes in the CDN with the plurality of delivery nodes bypassing content delivery requests from plurality of user equipments based on the plurality of bypass ratios of the plurality of delivery nodes, respectively; and send an indication of the at least the second delivery node (14b, 14c), for the content delivery to the user equipment, to the first delivery node. receive, from a first delivery node of a hierarchical layer of the CDN, a routing request to bypass the first delivery node for content delivery to a user equipment, wherein the routing request comprises at least a bypass ratio and an Internet Protocol, IP, address of the user equipment, and wherein the bypass ratio is a ratio of a number of content delivery requests that should bypass the first delivery node to a total number of content delivery requests assigned to the first delivery node and the bypass ratio is determined based on at least a processing load of the first delivery node; as a result of receiving the routing request to bypass the first delivery node for the content delivery to the user equipment, select at least a second delivery node (14b, 14c) for the content delivery to the user equipment, wherein the processing circuitry is further configured to select the at least second delivery node (14b, 14c) for the content delivery to the user equipment from one of a same hierarchical layer of the CDN as the hierarchical layer of the first delivery node and/or a higher hierarchical layer than the hierarchical layer of the first delivery node, the selection being dependent on at least a number of delivery nodes in the CDN that are determined to be in a bypass mode, and wherein the bypass mode is one of input/output protection modes for a plurality of delivery nodes in the CDN with the plurality of delivery nodes bypassing content delivery requests from plurality of user equipments based on the plurality of bypass ratios of the plurality of delivery nodes, respectively; and send an indication of the at least the second delivery node (14b, 14c), for the content delivery to the user equipment, to the first delivery node.