For ISPS: Motivations and methods for implementing fq_codel and cake

[dtaht]

At the ISP level I would really like some of these queuing disciplines to have native support for MPLS. The typical way to do QoS on an MPLS network is with EXP bits and not DSCP for the actual IP packet being transported. It would be ideal if something like cake could support prioritization based on MPLS EXP bits for backhaul links.

yea! the first actionable feature request I’ve had since the start of these threads. But I pointed out that a pure AQM might already work, and that the flow_dissector might already work also for fq-codel derived algos, with this kernel release. I am not in a position to test…

Secondly, cake supports putting things into 3 or 4 or 8 classes of service not just on the dscp bits, but on any “tc” filter you can write. Can a tc filter see the EXP bits? Can that be expressed in RouterOS?

Thirdly, there’s the spectre of ECN, I still have not the foggiest idea if access to those bits is working, nor what the current standard is for sticking them (if possible?) into MPLS.

I asked some questions based on this of the bufferbloat folk on the bloat and cake mailing lists.