The present invention relates to a method of a serving Radio Access Network (RAN) node for facilitating communication between a communication terminal and a core network in view of a handover of the communication terminal from said serving RAN node. The method comprises receiving a first message from the communication terminal, the message comprising a first message sequence number. The method also comprises producing a sequence number synchronization indicator (SNSI) arranged to indicate to a second RAN node to adjust a message sequence number of any future message from the communication terminal before forwarding said future message to the core network, such that the message sequence number of said future message is synchronized with a corresponding expected message sequence number of the core network. The method further comprises sending an update message to the second RAN node, wherein the update message comprises the SNSI.