In PSNs, sometimes it is not possible to distinguish and manipulate different kinds of network flows. For example, we may want to give priority to some flows while limiting bandwidth of other flows or even perform packet classification. To solve such problems, we have a traffic control layer in ns-3 which intercepts the packets flowing between the L2 Net devices and any IP protocol. It uses several qdiscs like pfifo, HBT, RED, CoDel etc., in order to process these packets and perform scheduling or shaping. Currently the ns-3 traffic layer only contains traffic scheduling qdisc models (AQMs) and lacks realistic traffic shaping algorithms. This project aims to introduce the TBF and HHF algorithms into the ns-3 traffic control layer. TBF is a classless traffic shaper, that is used to control the flow rate or bandwidth of the throughput. HHF is a size-based qdisc that attempts to differentiate small and heavy flows. The goal is to catch the heavy flows and move them to a separate queue with less priority so that bulk traffic does not affect the latency of critical traffic.




  • Stefano Avallone