Abstract: Methods, devices, and system related to cross-domain routing of communication session requests in Internet Protocol (IP) Multimedia Subsystem are disclosed. In one example aspect, a method for routing a call initiated in an IP Multimedia Subsystem (IMS) includes receiving, by a Breakout Gateway Control Function (BGCF) node operating in a first domain, a first message from a caller requesting an establishment of a communication session. The method includes determining, by the BGCF node based on header information of the first message, that the caller is located in a second domain different than the first domain, and generating, by the BGCF node, a second message based on a preconfigured rule for the second domain.

Abstract: Methods, devices, and system related to wireless communications are disclosed. In one example aspect, a method for wireless communications includes receiving, by a network node in a communication network, a packet associated with a call that has been initiated for a user device, and determining, by the network node, location information carried in a header of the packet. The method also includes determining, by the network node using a mapping between location information and Major Trading Area (MTA) values, an MTA value corresponding to the location information carried in the header, and routing, by the network node based on the MTA value, the packet using a routing path that bypasses a circuit-switched based network.

Abstract: Methods, devices, and system related to wireless communications are disclosed. In one example aspect, a method for wireless communications includes receiving, by a network node in a communication network, a packet associated with a call that has been initiated for a user device, and determining, by the network node, location information carried in a header of the packet. The method also includes determining, by the network node using a mapping between location information and Major Trading Are (MTA) values, a MTA value corresponding to the location information carried in the header, and routing, by the network node based on the MTA value, the packet using a routing path that bypasses a circuit-switched based network.

Abstract: A Breakout Gateway Control Function (BGCF) determines a geographic location information (e.g., a major trading area (MTA) information) from a SIP INVITE header information (e.g., from a P-Access-Network-Info (PANI) header information) and modifies the SIP URI in the SIP INVITE request by adding, deleting, or modifying values (e.g., prepending a number prefix to the URI) to generate a SIP URI that is based on the geographic location information.

Abstract: Methods, devices, and system related to cross-domain routing of communication session requests in Internet Protocol (IP) Multimedia Subsystem are disclosed. In one example aspect, a method for routing a call initiated in an IP Multimedia Subsystem (IMS) includes receiving, by a Breakout Gateway Control Function (BGCF) node operating in a first domain, a first message from a caller requesting an establishment of a communication session. The method includes determining, by the BGCF node based on header information of the first message, that the caller is located in a second domain different than the first domain, and generating, by the BGCF node, a second message based on a preconfigured rule for the second domain.