ADQ is a set of linux kernel queuing disciplines that provides delay guarantee and excess traffic support to real-time traffic and link sharing between real-time and best-effort traffic. It can also preserve the original ordering of all the real-time packets if transmitted. By supporting excess traffic, we allow real-time application to send unlimited volumn of traffic and shares the residue bandwidth with best-effort traffic.

The software comes as source codes for kernel modules which function as buffer management and scheduling for the output queue of network interface. Provided are two modules: jqueue and scfque. jqueue is a queuing discipline that uses SCED+ and SCFQ as scheduling algorithm with ADQ for excess traffic support. scfque is a queuing discipline that uses SCFQ alone as scheduling algorithm with ADQ. In both modules, packets are identified to be guaranteed, excess or best-effort packets based on TOS marking. Both module work with iproute2 package.

This work is supported by NSF grant ANI-9902943 and a grant from Nortel Networks. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.