Patent ID: 8667175

Claim:
A method comprising: receiving, by a content router, a plurality of first requests sent by an application of a client that has initiated downloading of a page containing a plurality of probe links that trigger the application to follow each of the probe links by sending the plurality of first requests, wherein the plurality of probe links are provided as images of pixels on the page, and wherein each probe link corresponds to a different geographic location hosting a plurality of servers; determining, by the content router, a particular server in each server location associated with a corresponding probe link of the plurality of probe links, the server location being a location at which the particular server could service a content request from the client; sending, by the content router, a plurality of redirect messages to the client, each redirect message being associated with the corresponding probe link and causing the client to: follow the redirect message to the particular server in the server location, receive back a redirect response from the particular server, and return a second request to the content router upon receipt of the redirect response, wherein an Internet protocol (IP) address of the client is associated with the second request for determining a roundtrip time for each particular server; associating, by the content server, each of the second requests with the corresponding probe link of the plurality of probe links; calculating, by the content router, a roundtrip time for each of the particular servers based on elapsed time from the redirect message that was sent from the content router to when the second request is received from the client; and designating, by the content router, a server location with the lowest calculated roundtrip time as a content deliverer to the client.