Traffic control within an IP multimedia subsystem

摘要

A method of handling traffic within an IP Multimedia Subsystem, IMS, network. The method comprises registering an IMS user with a first Serving Call Session Control Function, S-CSCF, of the IMS network. Subsequently, at the first S-CSCF, a decision is made or instruction received to transfer said user to an alternative, second S-CSCF within the IMS network. A notification is sent from said first S-CSCF to a further IMS node, the notification including an explicit instruction to select a second S-CSCF and, upon receipt of said notification at the further IMS node, an S-CSCF reselection initiated for the user in order to select a second S-CSCF.

主权项

1. A method of handling traffic within an IP Multimedia Subsystem (IMS) network, the method comprising:
registering an IMS user with a first Serving Call Session Control Function (S-CSCF) of the IMS network; the first S-CSCF making a decision or receiving an instruction to transfer said user to an alternative, second S-CSCF within the IMS network; as a result of the first S-CSCF making a decision or receiving an instruction to transfer said user to an alternative, second S-CSCF, the first S-CSCF sending to a further IMS node a notification comprising a request to select a second S-CSCF, wherein the step of the first S-CSCF sending to the further IMS node the notification to select a second S-CSCF comprises the first S-CSCF sending to a Proxy Call Session Control Function (P-CSCF) the notification to select a second S-CSCF; and upon receipt of said notification at the further IMS node, initiating an S-CSCF reselection for the user in order to select a second S-CSCF, wherein said notification includes an identification of said first S-CSCF, and said S-CSCF reselection for the user comprises including said identification together with an explicit instruction to select an alternative, second S-CSCF in an S-CSCF reselection request sent to an Interrogating Call Session Control Function, I-CSCF, of the IMS network.