The present invention relates to a method and an arrangement to maintain a TCP connection (230) between two hosts (140, 250) in a multi-hop network (110,120). If the connection (230) is inactive (no IP packets sent or received) during a certain period of time, it may happen that the connection (230) is released by certain intermediate network entities such as a Network Address Translation NAT function (130). The current invention overcomes this problem by sending keep-alive packets (210) from one of the hosts (250) towards the other (140) at regular intervals. Said packets (210) prevent the NAT (130) from releasing the connection (230). In order to not disturb the other host (140) e.g. a mobile terminal in a sleeping mode, the keep-alive packets (210) are adapted in such way that they are sent far enough to reach the NAT (130) but not all way to the other host (140).