The exponential growth of the mobile devices market, not only smartphones but also tablets, laptops or wearables, poses a serious challenge for 5G communications. Random linear network coding is a promising solution for present and future networks as it has been shown to provide increased throughput, security and robustness for the transmission of data through the network. Most of the analysis and the demonstrators have focused on the study of data packets with the same size (number of bytes). This constitutes a best-case scenario as coded packets will incur little overhead to handle such packets. However, packet lengths are quite heterogeneous in real networks, which can cause a high overhead or, alternatively, a high delay in the transmission of data packets. As we show, this can have a severe effect on a variety of applications. This paper proposes a series of mechanisms to manage heterogeneous packet lengths and analyses the induced overhead of those mechanisms using real packet length distributions provided by the Center for Applied Internet Data Analysis (CAIDA) and own measurements using video content. Our results show that an appropriate packetisation of the data packets can reduce the overhead from over 100 per cent (zero-padding packets) to below 5 per cent for CAIDA packet distributions and that the right choice of parameters can reduce the overhead to less than 10 per cent in the case of video data.