Abstract: A method to preserve the ordering of data packets of a same flow (P1-P4, P7, P8) passing either through a control plane (CP) or through a data plane (DP) of a telecommunication network element. The method comprises the step of, when the control plane starts processing the new flow, the control plane controls the data plane to latch any other packet belonging to this flow by sending a first control packet (C1) to said data plane. When the processing is completed, the control plane controls the data plane to release the latched packets by sending a second control packet (C3) to said data plane. The present method is particularly applicable to Ethernet frames, where it is also not allowed to reorder frames belonging to a same ‘Ethernet flow’.