Contiki’s IP networking uses the uIP network stack to handle the processing of the IP layer frames. The modularity
of this code meant that the DTN code could be directly integrated into Contiki’s network stack. This still allows for
nodes that did not support DTN to be built with the same codebase without incurring any processing or code space
overhead. The RPL routing system used by Contiki uses the hop by hop option for some of its information exchanges,
this meant that Contiki already had support for detecting hop by hop options and processing them. This code was
expanded to include the DTN header, allowing the DTN options to be inspected as part of the packets reception.