A method for establishing a packet data connection in a telecommunications system which includes an office network, an operator network, and a local area network between them. Data transmission from the office network through the local area network is adapted to a data transmission protocol according to a mobile system. The office network also includes a serving support node, a packet control unit, and a gateway support node, which are arranged to support the packet data protocol of the mobile system. The serving support node, packet control unit, and gateway support node are arranged to have a functional connection with each other and with a radio access gateway. A packet data connection request is made from a mobile station to the office network, and a packet data connection is established from the serving support node and gateway support node to a destination address defined by the link request.