1. A method for allocating a video conferencing task within a computer network, wherein the computer network comprises a plurality of Local Area Networks (LANs) interconnected by a Wide Area Network (WAN), wherein the video conferencing task relates to a video conference, wherein the computer network comprises a plurality of endpoints intended to participate in the video conference and a plurality of candidate processing devices, wherein the participating endpoints and the candidate processing devices are located in the LANs, and wherein at least one candidate processing device is one of the endpoints of the computer network, the method comprising: for each of the candidate processing devices: determining a topological score for the candidate processing device, the topological score being a function of at least one end-to-end delay between a pair of participating endpoints through the candidate processing device, wherein determining the topological score comprises: selecting a path for connecting the pair of participating endpoints through the candidate processing device, the path consisting of at least one of at least one LAN segment located in a LAN and at least one WAN segment located in the WAN, allocating a delay contribution to each LAN segment of the selected path, allocating a delay contribution to each WAN segment of the selected path, wherein the delay contribution of a WAN segment is longer than the delay contribution of a LAN segment, determining the end-to-end delay between the endpoints of the pair of participating endpoints as a sum of the delay contributions of the at least one of at least one LAN segment and at least one WAN segment constituting the path, for each candidate processing device within at least a subset of the candidate processing devices: determining an availability score for the candidate processing device, the availability score being a function of an available processing capacity of the candidate processing device, detecting that a processing device of the computer network to which a video conferencing task relating to a video conference was allocated is not able to continue performing the video conferencing task, selecting a preferred processing device among the candidate processing devices other than the processing device which is not able to continue performing the video conferencing task as a function of the topological scores and of the availability scores, and re-allocating the video conferencing task for the video conference between the pair of participating endpoints to the preferred processing device.