It has to be recognised that 'virtualisation' is a means to an end, not an end in itself. So what is the end? Well, one of them, Sam tells Martyn Warwick, is to program the network in such a way that telcos can maintain a rate of innovation equivalent to companies like Google. Sam is setting store in a standard called NSH - network service header - where a packet or stream of packets sent through the network essentially instructs the network on the treatment it expects. That way operators can define services for particular flows on the fly.