Patent ID: 8503433

Claim:
A method comprising: receiving, at a first session initiation protocol server associated with a first service provider, a first address of a first telephone number mapping server associated with a second service provider, wherein the first address is determined based on a carrier identifier received from a second telephone number mapping server associated with the first service provider, and wherein the carrier identifier and a destination telephone number are associated with the second service provider; receiving, at the first session initiation protocol server, a uniform resource identifier associated with the destination telephone number from the first telephone number mapping server based on the first address; and after receiving the uniform resource identifier, initiating establishment of a path of a call associated with the destination telephone, wherein the path of the call is established based on a second address of a second session initiation protocol server associated with the second service provider, and wherein the second address is received from a first domain name service server based on the uniform resource identifier.