There is provided an apparatus configured to perform method comprising: supporting a split bearer involving a first entity associated with a primary path of the split bearer and a second entity associated with secondary path of the split bearer, wherein the first entity and the second entity are configured for data transfer; determining a total amount of data volume for the data transfer; if the total amount of data volume for the data transfer is greater than or equal to a threshold value of the split bearer, submitting a Packet Data Convergence Protocol, PDCP, protocol data unit, PDU, to either the first entity or the second entity; if the total amount of data volume for the data transfer is less than the threshold value of the split bearer, submitting the PDCP PDU to the first entity if the primary path is available to use, and submitting the PDCP PDU to the second entity if the primary path is not available to use.