Re: Are there any alternatives to IFB for downlink shaping?

[Nick Pelling <nick.pelling@farncombe.com>]

Thanks very much for your quick replies, Andrew and Andy. :-)

In short: I'm trying to prioritize bandwidth between two groups of interfaces, so that users in the home group get priority over users in the guest group, all the while sharing the uplink bandwidth and downlink bandwidth nicely (i.e. nobody can monopolize the uplink or downlink bandwidths etc).

And yes: in an ideal world, downlink traffic would be shaped at the other end of the DSL line (because by the time packets have arrived, the downlink bandwidth has already been hogged), hence downlink shaping is indeed "on the wrong end of the bottleneck".

But it seems that the only 'control lever' a home/guest Linux wireless gateway could 'pull' to try to discourage such downlink bandwidth hogs would be delaying or perhaps even dropping their packets, even if those packets arrived OK. And though that's not a great answer, that's just about the only answer I can see.

All the same, thanks for your specific suggestions: I shall go and try them out and hopefully come back when they're all working as well as the uplink shaping. ;-)

My $0.02's worth: I suspect that the ongoing explosion in WiFi devices means that QoS and local traffic management are now about to be reluctantly pushed centre stage, because the humble wireless gateway now has all kinds of real-time traffic competing and colliding. The R&D I'm doing at the moment is just a small part of this very much wider landscape: but I do wonder whether the current set of tc qdiscs and filters will prove to be up to the job.