To reduce and/or guarantee the round-trip delay of interactive processes, cooperative scheduling in forward and backward direction is proposed. In practice, a basic idea is to estimate the delay of packets of different users during network-based scheduling of packets in forward direction. During scheduling of packets in backward direction, packets of those users having larger delay in forward direction are given higher priority based on the estimated delay. In this way the total round-trip delay can be reduced and/or even guaranteed. This means that more users will be satisfied and experience faster connections to services.