Patent ID: 8594062

Claim:
A method for transmitting initiation information related to a SIP-proxy server between an IMS-client stored in a user equipment (UE) and a Gateway GPRS Support Node (GGSN) via a Access Network (AN) and a Tunnelling Termination Gateway (TTG) node of an IP core network, said method comprises following steps of: receiving IPsec/IKE signalling at said TTG node from said UE; activating PDP-context signalling comprising a request for initiation information towards said GGSN node in response to said UE IPsec/IKE signalling; receiving from said GGSN node initiation information comprising a SIP-proxy server address information; receiving at said TTG node a DHCP-query concerning said SIP-proxy server address information from said UE after said IPsec/IKE signalling has been completed; and transmitting from said TTG node said SIP-proxy server address information in response to said DHCP-query to said UE.