Patent ID: 7920558

Claim:
A method of operating a data network, of the type in which a number of interconnected router devices forward received packets of data towards a destination node in accordance with a routing table associated with each router, the method comprising: assigning a trust value to one or more other router devices, or one or more links between router devices, in the network; calculating a route metric in respect of one or more paths for forwarding on received data packets for onward transmission towards a specified destination; and selecting a next hop destination for onward transmission of each such received packet to be forwarded on the basis of the calculated route metric for each applicable path, wherein each route metric is calculated in dependence upon the trust value assigned to one or more of the router or routers or link or links within each such path, and wherein the trust value is based on a number of factors including a plurality of observed trust factors and a plurality of inherent trust factors, the inherent trust factors including a factor based on the entity responsible for the respective router or the router terminating the respective link.