1. A method comprising: outputting in a packet data network a first data packet from a network party towards a terminal; associating the first data packet with a time-to-live (TTL) adjusted to enable the first data packet to reach one or more intervening network entities but not to enable the first data packet to reach the terminal, in order to maintain traffic through the one or more intervening network entities to postpone expiry of a connection between the terminal and the network party in the one or more intervening network entities; and determining the number of hops remaining on the route of the first data packet to the terminal and the time-to-live associated with the first data packet is adjusted so that the time-to-live is set to be smaller than the determined number of hops.