The content layer has a simple deployment path, based on user need and on an ISP's motivation to provide a better web experience to customers and superior service to colocated service providers. INRP and NBRP can initially be implemented in ISP name servers, which fail over to normal DNS behavior for unrecognized names. INRP provides a way for ISPs to quickly direct their customers to colocated servers, eliminating any need for name requests to leave their network. NBRP is not strictly needed, but may prove a convenient way to advertise new content to an ISP's name servers.
This initial deployment requires no changes to end hosts and no change to the basic IPv4 routers and switches constituting the infrastructure of the leaf and backbone networks. It only requires the deployment of content routers, which can be implemented on top of existing hardware using packet filtering and redirection techniques. In particular, hosts still use conventional DNS lookup to get an address, but benefit from reduced dependence on distant root name servers and lower latency to access local content servers. However, some customers may be running their own name servers and avoiding the use of ISP DNS servers, and thus see no benefit until they reconfigure.
The overhead of doing content routing in this manner is very small, since the ISP's name server already does DNS packet handling. Only the cost of accessing the name-based routing table would be wasted on names not in the content routing system-- much less than the 0.5 ms described above.
ISPs who already peer at the IP routing level are motivated to peer at the content routing level to provide their customers faster access to nearby content servers-- and increase the benefit of placing content servers in their network. As demand grows, additional content routers can be placed to handle the increased usage without user-visible changes. As the content routing topology evolves to more closely matches IP routing topology, the content routing system can make more accurate decisions.