Patent ID: 8649378

Claim:
A method implemented by a Domain Name Server (DNS) system for controlling the routing of data packets in an IP network, the method comprising: storing a packet admission policy in the DNS system, the packet admission policy configured for a first end-host and that dictates conditions for allowing or not allowing other end-hosts to convey data packets to the first end-host; the DNS system defining a routing voucher for the first end-host corresponding to the packet admission policy, the routing voucher or a representation of the routing voucher being required in data packets directed to the first end-host for routing said data packets towards the first end-host; the DNS system distributing said routing voucher or the representation of the routing voucher to at least one router in the IP network; the DNS system receiving an address query for the first end-host from a second end-host; the DNS system supplying the routing voucher or the representation of the routing voucher to the second end-host if the packet admission policy allows the second end-host to convey data packets to the first end-host, the second end-host then being able to add the routing voucher or the representation of the routing voucher to any data packets directed to the first end-host for admission through the IP network; and the DNS system refraining from supplying the routing voucher or the representation of the routing voucher to the second end-host if the packet admission policy does not allow the second end-host to convey data packets to the first end-host; wherein the DNS system is distinct from the at least one router in the IP network.