A method for communication, in a network element that includes multiple ports, includes buffering data packets entering the network element via the ports in input buffers that are respectively associated with the ports. Storage of the data packets is shared among the input buffers by evaluating a condition related to the ports, and, when the condition is met, moving at least one data packet from a first input buffer of a first port to a second input buffer of a second port, different from the first port. Respective output ports, via which the buffered data packets are to exit the network element, are selected from among the ports. The buffered data packets are forwarded to the selected output ports.