A method for assisting in multipoint data flow control in a wireless communication system having a number, n+1, where n≥1, of wireless-transmission points. The method comprises obtaining, for each of the wireless-transmission points, a round trip time of a present sampling period for data travelling to a user equipment via a respective wireless-transmission point and an acknowledge message travelling back. A round trip time skew is computed for the present sampling period for individual wireless-transmission points. The round trip time skew is a difference between the obtained round trip time of a respective wireless-transmission point and a reference value. A reference round trip time value is provided for each wireless-transmission point in dependence of the round trip time skews. A rate control signal is generated, for each of the wireless-transmission points, in dependence of a respective reference round trip time value. Corresponding arrangements are also disclosed.