Method and arrangement for implementing certain negotiations in a packet data network

The invention concerns generally the protocol structures that are used to arrange the communication between a mobile terminal and a packet-switched network. Especially the invention concerns the optimal composition of such structures and the arrangement of negotiations where the protocol-determined parameters relating to the communication are agreed upon. A method is disclosed for a mobile station (MS) for negotiating a set of Layer 3 parameters with a network device (NW) in association with the setup of a new Packet Data Protocol context. A request message () is created for requesting the setup of a new Packet Data Protocol context, and a set of suggested Layer 3 parameters () is inserted into the created request message. The request message is transmitted to the network device. After receiving from the network device a set of agreed Layer 3 parameters (), they are employed within the new Packet Data Protocol context the setup of which was requested.