Enabling a communication server to use msc-s related functions

A hosting switching node of a circuit switched, CS, network comprising an instant communication server which is adapted to communicate over an instant communication protocol with an instant communication client which is associated to a mobile subscriber of the CS network, wherein the hosting switching node further comprises a message converter which comprises:

• a receiver, adapted to receive a CS setup message for setup a CS call to the mobile subscriber;
• a processor, adapted to convert the CS setup message into a converted setup message which is based on the instant messaging protocol;
• and
• a transmitter, adapted to transmit the converted setup message to the instant communication server.

A media gateway, MGW, node of a circuit switched network, CS, which is controlled by a hosting switching node of a CS network, the MGW node comprising:

• a receiving unit, adapted to receive a request for providing a relay function between an instant communication client and a message converter associated to the hosting switching node;
• a processing unit, adapted to determine an address of a local port to which the instant communication client can be terminated and an address of a remote port to which the message converter can be terminated;
• a relay function, adapted to relay media data between the local port and the remote port;
• and
• a sending unit, adapted to send to the switching node the address of the local port and the address of the remote port.