Network domain selection
View Patent ↗For an incoming session intended for a user element, a domain selection function (DSF) is provided in a multimedia subsystem (MS) to select a circuit-switched subsystem (CS) or MS domain to use when routing the incoming session to the user element. Regardless of the domain in which incoming sessions are originated, the incoming sessions intended for the user element are routed to an S-CSCF in the MS. The S-CSCF directly or indirectly employs the DSF to determine whether to use the MS or the CS for terminating the incoming session. Based on available domain selection criteria, the DSF will select an appropriate domain, such as the MS or CS, to use for routing the incoming session to the user element. The domain selection decision of the DSF is provided to the S-CSCF, which will proceed by routing the incoming session to the user element via the selected domain.
1. A method for transferring a call established by a first client to second client, the method comprising:
establishing a call via a first client;
sending a setup message from the second client on a user element to initiate transfer of the call from the first client to the second client;
receiving the setup message at a continuity control function (CCF) which is currently anchoring the call;
in response to receiving the setup message, sending a message including an identity of the CCF to a media gateway controller;
at the media gateway controller, initiating an invite message to a serving call session control function (S-CSCF) including the identity of the CCF and identifying the media gateway controller as a representative of the user element in a domain for the call; and
at the S-CSCF, forwarding the invite message to the CCF, and, at the CCF, sending an update to a remote endpoint to effect a transfer of the call to the second client.
2. A method for transferring a call supported by a first client to a second client, the method comprising:
establishing a call with a first client;
sending an invite message to a serving call session control function (S-CSCF) to initiate transfer of the call to a second client associated with a user element, wherein the invite message includes an identity for a continuity control function (CCF) and identifies the second client as an endpoint for communications;
passing the invite message to the CCF;
at the CCF, sending an update message towards a remote endpoint via the S-CSCF, wherein the update message identifies the current domain after the transfer is effected and session description protocol (SDP) information for the second client;
at the S-CSCF, storing the current domain information and forwarding the update message toward the remote endpoint; and
exchanging messaging between the user element and the remote endpoint via the signaling path, which traverses the CCF to allow a bearer path to the second client.
3. A system for transferring a call established by a first client to a second client, the system comprising:
a first client for establishing a call;
a second client associated with a user element for sending a setup message to initiate transfer of the call from the first client to the second client;
a continuity control function (CCF) for anchoring the call, for receiving the setup message, and for sending a message including an identity of the CCF;
a media gateway controller for initiating an invite message including the identity of the CCF, wherein the invite message identifies the media gateway controller as a representative of the user element in a domain for the call; and
a serving call session control function (S-CSCF) for receiving the invite message and for forwarding the invite message to the CCF, wherein the CCF sends an update to a remote endpoint to effect a transfer of the call to the second client.
4. A system for transferring a call supported by a first client to a second client, the system comprising:
a first client for establishing a call;
a continuity control function (CCF) for sending an invite message to a serving call session control function (S-CSCF) to initiate transfer of the call from the first client to a second client associated with a user element, wherein the invite message includes an identity for the CCF and identifies the second client as an endpoint for communications, wherein the CCF sends an update message towards a remote endpoint via the S-CSCF, wherein the update message identifies a current domain after the transfer is effected and session description protocol (SDP) information for the second client;
wherein the S-CSCF stores the current domain information and forwards the update message toward the remote endpoint; and
wherein messaging is exchanged between the user element and the remote endpoint via the signaling path, which traverses the CCF, to allow a bearer path to the second client.