. QoS Broker The QoS broker (QoSB) comprises: an engine, responsible for taking all management decisions, and several different interfaces to inter- operate with other entities, using COPS (common open policy service); an AR interface used both for letting the AR pool the broker for policies related to the services that the attached users are requesting and for configuring the AR with that specific policy; an AAAC interface used to exchange messages with the AAAC, to inform the QoSB of every new MT/user that attaches to its domain (including the NVUP information for that user) and to require specific user and service information; a QoSB interface used for exchanging information between QoS brokers. QoS End-to-End Support The provision of end-to-end QoS gives rise to three different aspects. Registration The registration process initiates after the MT acquires the care of address (CoA) via auto configuration. However, this does not entitle the user to use the resources and the MT needs to send the authentication information to the AR in order to use the resources later. This information is then forwarded to the AAAC system and on successful authentication it dumps the NVUP to the QoS broker and informs the MT via the AR. Authorization In the next step each network service is authorised. The MT first sends a packet with an appropriate DSCP code to request a particular service. If the requested packet does not match any policy set in the AR, the AR sends a request to the QoSB via the QoS manager. On analysing the request and based on available NVUP and the available resources, the QoSB sends a confirmation back to the AR. The QoS manager in the AR then configures the appropriate policy for that user/MT service in the AR and after that any packet matching the configured policy will be able to cross the network. QoS Enabled Handover Maintaining a constant level of QoS will be the main problem involved in IP mobility scenarios. Fast handover techniques are guaranteed to the user in the context of a transfer between the