HTBQueue: A Hierarchical Token Bucket Implementation for the OMNeT++/INET Framework

The hierarchical token bucket (HTB) algorithm allows to specify per-flow bitrate guar-
antees and enables excess bandwidth sharing between flows of the same class. Addition-
ally, it provides capabilities to prioritize the traffic of specific flows, potentially considering
their delay demands. HTB hence constitutes a powerful mechanism to enforce QoS re-
quirements hierarchically and on a fine granular per-flow level, making it an appropriate
choice in numerous use-cases. In this paper, we present HTBQueue, our implementation
of a compound module for HTB support in the discrete event simulator OMNeT++. We
validate HTBQueue’s functionality in terms of rate conformance and fair bandwidth shar-
ing behavior between competing flows. We furthermore demonstrate its support for flow
prioritization.