Patent ID: 11936694
Assignee: T-MOBILE USA, INC.
Field: Digital communication (Electrical engineering)
Classification: CPC H | IPC H

Claim 14:
15. A system for providing Internet Protocol (IP) Multimedia services to users, comprising:
a first network node configured to receive a request from a caller in a first domain requesting an establishment of a communication session; and
a second network node operating in a second domain configured to receive the request originated from the first network node, wherein the second network node is configured to:
determine, based on header information of the request, that the caller is located in the first domain that is different than the second domain,
generate, without a Call Session Control Function (CSCF) network server querying an Electronic Numbering (ENUM) server, a new request based on a preconfigured rule,
wherein the preconfigured rule represents an agreement between a first carrier of the first domain and a second carrier of the second domain, the agreement indicating that a subset of calls from the first domain is routed by the second domain,

wherein the new request includes a routing number field formed by adding one or more routing digits that corresponds to a third network node to (1) a call number carried in the request in response to the call number not being a ported number or (2) a local routing number assigned to the caller in response to the call number being a ported number, and

route the new request to the third network node to establish the communication session.