A method of collecting charging information relating to usage of the Internet by an Internet user. The method comprises constructing in a router of the Internet a routing table containing a set of destination address ranges and a set of respective next hop network nodes. Each address range in the routing table is assigned a cost class in dependence upon the route via which a packet must travel to an address within the range. Upon receiving a data packet from the network user, the destination address of the packet is identified by the router. The router then determines from the routing table the associated cost class. A corresponding cost class counter in the router is then incremented.