A method of routing packets between nodes of a packet switched network, the method comprising receiving a packet at a first node, the packet comprising routing information and payload data, sending said routing information to a second node in the routing path via a first transmission medium having a relatively high transmission speed, and sending said payload data to said second node via a second transmission medium having a relatively low transmission speed. Upon receipt of said routing information, said second node is able to prepare or begin preparation for onward routing of the packet in advance of receipt of said payload.