Patent ID: 8730951
Filing Date: 2014-05-20
Classification: H04L

Abstract:
1. A method, comprising: transmitting, by a telephone number mapping (ENUM) server, a first name authority pointer (NAPTR) to an originating call session control function (CSCF) server, wherein the first NAPTR comprises a session initiation protocol (SIP) uniform resource identifier (URI) associated with a terminating device; receiving, by the originating CSCF server, one of an identity of a terminating CSCF server associated with the terminating device or a notification of an unsuccessful identification of the terminating CSCF server; transmitting, by the originating CSCF server and responsive to receiving of the identity of the terminating CSCF server, the SIP URI of the first NAPTR to the terminating CSCF server to initiate a packet-switched communication session; transmitting to the originating CSCF server, by the ENUM server, the second NAPTR comprising a telephone protocol (tel) URI associated with the terminating device responsive to receiving the notification of the unsuccessful identification of the terminating CSCF server; and transmitting to a media gateway control function (MGCF) server, by the originating CSCF server and responsive to the originating CSCF server receiving the second NAPTR, the tel URI of the second NAPTR to initiate a circuit-switched communication session.