The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 05, 2009
Filed:
Jan. 13, 2006
Armstrong Soo, San Francisco, CA (US);
Blair Lane Porter, Ballwin, MO (US);
Bernard Siu-man Ku, Austin, TX (US);
Phyllis G. Anderson, Austin, TX (US);
Armstrong Soo, San Francisco, CA (US);
Blair Lane Porter, Ballwin, MO (US);
Bernard Siu-Man Ku, Austin, TX (US);
Phyllis G. Anderson, Austin, TX (US);
AT&T Intellectual Property L.L.P., Reno, NV (US);
Abstract
A Voice over Internet Protocol (VoIP) call from a first provider to a destination telephone number served by a second provider comprises sending a Session Initiation Protocol (SIP) INVITE message from an originating switch to a first SIP server of the first provider. The first SIP server queries a telephone number mapping (ENUM) server of either the first, second or a third provider, and receives a Uniform Resource Identifier (URI) associated with the destination telephone number. The ENUM server may be internal or external to the first provider. The first provider queries a Domain Name Service (DNS) server based on the URI, and receives an Internet Protocol (IP) address of a second SIP server of the second provider. The first SIP server and the second SIP server are used to set up a bearer path for the VoIP call between the originating switch and a destination switch.