US Patent 9525659 Request routing utilizing point of presence load information

A system, method and computer-readable medium for request routing based on prioritization and load information are provided. A client request processing a resource identifier for requested content transmits a DNS query to a content delivery network service provider. Based on a content provider identifier included in the DNS query, a receiving DNS nameserver determines a selection from a hierarchical organization of POPs and the relative capacity for a selected POP to process a subsequent request for resources. Based on the processing of the prioritization information and load information, the receiving DNS nameserver resolves the DNS query.