| 摘要 |
A method and apparatus for calculating a distance in a content delivery network are disclosed. According to a preferred embodiment of the present invention, when a domain name resolution request is received from an LDNS, a canonically named domain name reply is generated by adding an identifier to a resolution-requested domain name and transmitted to a probe server. A source IP address corresponding to the canonically named domain name reply transmitted to the probe server is changed to the address of a name server in the probe server and delivered to the LDNS. The name server receives a resolution request for the canonically named domain name reply from the LDNS and calculates a distance between the LDNS and a POP by subtracting the distance between the name server and the LDNS and the distance between the name server and the probe server from a time interval between a time when the name server transmits the canonically named domain name reply to the probe server and a time when the name server receives the resolution request for the canonically named domain name reply from the LDNS. According to the present invention, the distance between the LDNS and the POP can be calculated even when the probe server cannot calculate the distance to the LDNS, and thus CDN server quality can be improved and CDN service can be stabilized. |
