Abstract: Network nodes for an access network and a home network of a first UE are described for use when routing an originating call from the first UE in the access network including an IMS network. A network node receives a SIP INVITE message associated with the originating call from the first UE, and including a called party number associated with the call. The network node determines whether the first UE is visiting the access network and whether the called party number is associated with the access network. The network node determines whether the called party number is allowable in the access network. The network node modifies and transmits the received SIP INVITE message towards a home network of the first UE to cause the home network to route the originating call to the access network.

Abstract: A method of managing a media path for a media session established between users across a plurality of interconnected Internet Protocol (IP) networks which utilize Session Initiation Protocol (SIP) and Session Description Protocol (SDP) signaling. The method comprises, at session establishment via a signaling path over the IP networks, making a determination that a shortcut media path is available, wherein the shortcut media path deviates from the signaling path. The method further comprises making a further determination that nodes in the signaling path will subsequently be able to maintain the shortcut media path in the event of a subsequent session update or re-invite and, at a subsequent session update or re-invite, including within update or re-invite signaling an indication that the shortcut media path is to be maintained.

Abstract: Requests between first and second IMS network domains are communicated by receiving an XDM request in the first domain. The XDM request relates to an XML document that can be accessed via the XDM request from a location in the second domain. A SIP request is created that includes information identifying it as a request that relates to an XDM request. The SIP request is sent to the second domain so that the SIP request can be routed to the location in the second domain based on the identifying information in the SIP request. A connection for XDM requests between the first and second domains is established.

Abstract: A method of routing a session from a calling party in a serving communication network of the calling party to a called party is described. The serving communication network of the calling party is distinct from a home communication network of the calling party. The method is executed by a session routing node in the serving communication network of the calling party. In order to optimize a session routing path of signaling data of the session, the method comprises receiving from the home communication network of the calling party a session routing request requesting routing the signaling data of the session to the called party via the serving communication network of the calling party, and routing the signaling data of the session to the called party via the serving communication network of the calling party based on the received session routing request.

Abstract: System, methods, nodes, and computer program for determining a home network of a UE roaming in a visited network are described. The UE sends a session invitation to a further UE. The method comprises receiving, by a control node in the home network, the session invitation. The method further comprises adding, by a control node in the home network, an indication of the home network identity and an indication for session invitation loopback routing, to the session invitation. The method further comprises sending, by a control node in the home network, the session invitation towards the visited network. The method further comprises receiving, by a control node in the visited network, a session invitation from the home network. The method further comprises determining, by the control node in the visited network, the home network based on the indication of the home network identity.

Abstract: A method of managing a media path for a media session established between users across a plurality of interconnected Internet Protocol (IP) networks which utilize Session Initiation Protocol (SIP) and Session Description Protocol (SDP) signaling. The method comprises, at session establishment via a signaling path over the IP networks, making a determination that a shortcut media path is available, wherein the shortcut media path deviates from the signaling path. The method further comprises making a further determination that nodes in the signaling path will subsequently be able to maintain the shortcut media path in the event of a subsequent session update or re-invite and, at a subsequent session update or re-invite, including within update or re-invite signaling an indication that the shortcut media path is to be maintained.

Abstract: During a registration procedure by a User Equipment (UE) via a Proxy Call Session Control Function (P-CSCF) node and a Serving Call Session Control Function (S-CSCF) node, the S-CSCF node provides a policy indicator in a response message to a register request message. The policy indicator enables subsequent operation of the node to be controlled according to whether or not a registered UE has an associated policy. As such, delays (such as delays associated with retrieving an associated policy) are only experienced by UEs that have previously been determined as having such an associated policy, rather than all UEs being affected in the same way.

Abstract: Network nodes for an access network and a home network of a first UE are described for use when routing an originating call from the first UE in the access network including an IMS network. A network node receives a SIP INVITE message associated with the originating call from the first UE, and including a called party number associated with the call. It determines whether the first UE is visiting the access network and whether the called party number is associated with the access network. A query to a database is performed, the database comprising a plurality of called party numbers, as to whether the called party number is allowable for use in the access network when the UE is visiting and when the called party number is associated with the access network. Instructing the home network to route the originating call to the access network when a response from the query indicates the called party number is allowable for use in the access network.

Abstract: A method of routing a session from a calling party in a serving communication network of the calling party to a called party is described. The serving communication network of the calling party is distinct from a home communication network of the calling party. The method is executed by a session routing node in the serving communication network of the calling party. In order to optimize a session routing path of signaling data of the session, the method comprises receiving from the home communication network of the calling party a session routing request requesting routing the signaling data of the session to the called party via the serving communication network of the calling party, and routing the signaling data of the session to the called party via the serving communication network of the calling party based on the received session routing request.

Abstract: A method of routing a session from a calling party in a serving communication network of the calling party to a called party is described. The serving communication network of the calling party is distinct from a home communication network of the calling party. The method is executed by a session routing node in the serving communication network of the calling party. In order to optimize a session routing path of signaling data of the session, the method comprises receiving from the home communication network of the calling party a session routing request requesting routing the signaling data of the session to the called party via the serving communication network of the calling party, and routing the signaling data of the session to the called party via the serving communication network of the calling party based on the received session routing request.

Abstract: Methods and apparatus are described for use in handling session establishment in a home network or visited network. IMS roaming is described for a UE of the home network that is roaming in the visited network. On receipt of a session establishment request associated with an originating call from the UE the home network determines whether to perform home routing and/or direct home routing of the originating call to the called party. When home routing, execution of service invocation is suspended and the home network sends a session establishment request including a routing number of an application server in the home network back to the visited network, which performs visiting service invocation of the call and routes the signaling and media to the home network-based on the routing number. The network node in the home network resumes execution of service invocation and routing of the originating call to the called party.

Abstract: A method of facilitating access to services of an IP Multimedia Subsystem network by services located behind an access point to said network. The access point is associated with a subscription to the IP Multimedia Subsystem network. The method comprises including within an Implicit Registration Set defined for said subscription, a wildcarded Public Service Identity or Public Service Identity sub-domain representative of a range of Public Service Identities. At IP Multimedia Subsystem registration of said access point with the IP Multimedia Subsystem network, the Public Service Identities contained in the Implicit Registration Set are distributed to a Serving Call Session Control Function allocated to said access point and to a Proxy Call Session Control Function to which said access point is attached.

Abstract: Requests between first and second IMS network domains are communicated by receiving an XDM request in the first domain. The XDM request relates to an XML document that can be accessed via the XDM request from a location in the second domain. A SIP request is created that includes information identifying it as a request that relates to an XDM request. The SIP request is sent to the second domain so that the SIP request can be routed to the location in the second domain based on the identifying information in the SIP request. A connection for XDM requests between the first and second domains is established.

Abstract: During a registration procedure by a User Equipment (UE) via a Proxy Call Session Control Function (P-CSCF) node and a Serving Call Session Control Function (S-CSCF) node, the S-CSCF node provides a policy indicator in a response message to a register request message. The policy indicator enables subsequent operation of the node to be controlled according to whether or not a registered UE has an associated policy. As such, delays (such as delays associated with retrieving an associated policy) are only experienced by UEs that have previously been determined as having such an associated policy, rather than all UEs being affected in the same way.

Abstract: A method of routing a session from a calling party in a serving communication network of the calling party to a called party is described. The serving communication network of the calling party is distinct from a home communication network of the calling party. The method is executed by a session routing node in the serving communication network of the calling party. In order to optimize a session routing path of signaling data of the session, the method comprises receiving from the home communication network of the calling party a session routing request requesting routing the signaling data of the session to the called party via the serving communication network of the calling party, and routing the signaling data of the session to the called party via the serving communication network of the calling party based on the received session routing request.

Abstract: A method of facilitating access to services of an IP Multimedia Subsystem network by services located behind an access point to said network. The access point is associated with a subscription to the IP Multimedia Subsystem network. The method comprises including within an Implicit Registration Set defined for said subscription, a wildcarded Public Service Identity or Public Service Identity sub-domain representative of a range of Public Service Identities. At IP Multimedia Subsystem registration of said access point with the IP Multimedia Subsystem network, the Public Service Identities contained in the Implicit Registration Set are distributed to a Serving Call Session Control Function allocated to said access point and to a Proxy Call Session Control Function to which said access point is attached.

Abstract: Methods and a communications node provide for routing communications over interconnected operator networks. These communications can be routed between individuals and/or organizations. Typically these communications are routed based upon information located in a database (410) and stored in session initiation protocol (SIP) communications.

Abstract: Systems and methods according to these exemplary embodiments provide for methods and systems for routing communications from a serving network to an enterprise network. Access point information associated with users in the enterprise network is stored and accessible for use by the serving network.

Abstract: A method of facilitating access to services of an IP Multimedia Subsystem network by user terminals and services located behind an access point to said network. The access point is associated with a subscription to the IP Multimedia Subsystem network. The method comprises including within an Implicit Registration Set defined for said subscription, a wildcarded Public User Identity, Public Service Identity, Public User Identity sub-domain representative of a range of Public User Identities, or Public Service Identity sub-domain representative of a range of Public Service Identities. At IP Multimedia Subsystem registration of said access point with the IP Multimedia Subsystem network, the Public User Identities and Service Identities contained in the Implicit Registration Set are distributed to a Serving Call Session Control Function allocated to said access point and to a Proxy Call Session Control Function to which said access point is attached.

Abstract: A method of facilitating access to services of an IP Multimedia Subsystem network by user terminals located behind an access point to said network. The access point is associated with a subscription to the IP Multimedia Subsystem network. The method comprises including within an Implicit Registration Set defined for said subscription, a wildcarded Public User Identity or Public User Identity sub-domain representative of a range of Public User Identities. At IP Multimedia Subsystem registration of said access point with the IP Multimedia Subsystem network, the Public User Identities contained in the Implicit Registration Set are distributed to a Serving Call Session Control Function allocated to said access point and to a Proxy Call Session Control Function to which said access point is attached.