It is presented a method for assisting a resource allocation transfer of a wireless device from a source site of a mobile communication network to a target site of the mobile communication network. The method is performed in a service function node at the source site and comprises the steps of: receiving an indication of resource allocation transfer of the wireless device; and transmitting a reset signal to a user service node at the source site, the reset signal commanding the user service node to reset its transport layer session with the wireless device.