A mobile switching centre server configured to handle control plane information exchange and to select a multimedia gateway for switching and carrying for user data traffic, the mobile switching centre server comprising: means for receiving a connection establishment request which indicates that a circuit-switched data stream is to be delivered over IP; means for determining whether the connection establishment request originates from a home subscriber; means for determining whether the connection establishment request is targeted to a home subscriber; means for determining, in case the connection establishment request originates from a home subscriber, whether the connection establishment request is targeted to a cared of subscriber that is either a home subscriber or a visiting subscriber served by the mobile switching centre server; means for checking, in case that the connection establishment request is targeted to a home subscriber, whether the home subscriber is roaming; means for forwarding, in case that the connection establishment request is targeted to a home subscriber that is roaming, the connection establishment request towards the home subscriber that is roaming; means for receiving a response to the forwarded connection establishment request; means for checking whether the response to the forwarded connection establishment request contains information on a multimedia gateway; means for forwarding, in case the response to the forwarded connection establishment request contains information on the multimedia gateway, received information on the multimedia gateway in a response to a party from whom the connection establishment request was received; means for sending, in case that the connection establishment request is not targeted to a home subscriber and the connection establishment request does not originate from a home subscriber or in case that the connection establishment request is targeted to a visiting subscriber served by the mobile switching centre server and the connection establishment request originates from a home subscriber, a second connection establishment request to the targeted subscriber; means for receiving an acceptance of the second connection establishment request; means for reserving, in case that an acceptance of the second connection establishment request is received or the response to the forwarded connection establishment request does not contain information on a multimedia gateway, multimedia gateway resources for user traffic to be sent over the connection from the multimedia gateway; and means for sending, in case that multimedia gateway resources are reserved, a response including the address of the multimedia gateway to the party from whom the connection establishment request was received. means for receiving a connection establishment request which indicates that a circuit-switched data stream is to be delivered over IP; means for determining whether the connection establishment request originates from a home subscriber; means for determining whether the connection establishment request is targeted to a home subscriber; means for determining, in case the connection establishment request originates from a home subscriber, whether the connection establishment request is targeted to a cared of subscriber that is either a home subscriber or a visiting subscriber served by the mobile switching centre server; means for checking, in case that the connection establishment request is targeted to a home subscriber, whether the home subscriber is roaming; means for forwarding, in case that the connection establishment request is targeted to a home subscriber that is roaming, the connection establishment request towards the home subscriber that is roaming; means for receiving a response to the forwarded connection establishment request; means for checking whether the response to the forwarded connection establishment request contains information on a multimedia gateway; means for forwarding, in case the response to the forwarded connection establishment request contains information on the multimedia gateway, received information on the multimedia gateway in a response to a party from whom the connection establishment request was received; means for sending, in case that the connection establishment request is not targeted to a home subscriber and the connection establishment request does not originate from a home subscriber or in case that the connection establishment request is targeted to a visiting subscriber served by the mobile switching centre server and the connection establishment request originates from a home subscriber, a second connection establishment request to the targeted subscriber; means for receiving an acceptance of the second connection establishment request; means for reserving, in case that an acceptance of the second connection establishment request is received or the response to the forwarded connection establishment request does not contain information on a multimedia gateway, multimedia gateway resources for user traffic to be sent over the connection from the multimedia gateway; and means for sending, in case that multimedia gateway resources are reserved, a response including the address of the multimedia gateway to the party from whom the connection establishment request was received.