Patent ID: 8296443

Claim:
A method of a third party service provider for retrieving a network-service address of at least one network-service offered by an Internet Protocol Multimedia Subsystem (IMS) network of a first IMS operator, wherein the third party service provider has no business agreement with the first IMS operator but does have a business agreement with a second IMS operator providing a second IMS network, the method comprising: activating an application of the third party service provider from a mobile station via a first network; establishing an IMS-session between the third party service provider and the mobile station via the first IMS network, and via the second IMS network; retrieving the network-service address of the at least one network-service at the application of the third party service provider, wherein the network-service address has been inserted into a mobile originated SIP message of the IMS-session at a session managing node of the first IMS network; determining by the application of the third party service provider whether the application requires a network-service provided by the IMS network of the first operator; and accessing a required network-service from an application server of the IMS network of the first operator via the first network using the retrieved network-service address.