Uplink is faster than my CRS109 can handle, should I still use QoS?

I recently upgraded from a 50/5mbit to a 1gigE solution for my upstream provider. My CRS109 is able to manage around 325/325mbit which is pretty good but less than the capability of the uplink (I managed to get around 750/350 using my laptop direct into my providers equipment). I’m planning on replacing it with a CCR1009-8G and actually had some questions about it (though perhaps for another post).

In the meantime, though, I’m wondering if I should still be considering QoS (using either the hardware or software queues)? I realize the software queues might lower my overall performance but I was wondering if that would avoid potential congestion? I don’t see using 325mbit particularly often (but for when folks come over for LAN parties, I could see hitting it).

Thoughts or ideas?

QoS is only useful when the link is congested.

So I would turn it off !

I think QoS could be justified depending on your situation…


This is true, except your case is special because the router is going to be the limiting factor. If the router simply can’t forward packets fast enough, then random traffic is going to be dropped when the CPU is pegged. This will essentially be the same as congestion, so if you do have priority traffic that should be forwarded even when the CPU is nearing its limits, then QoS can still help you.

You’ll have to use queues to limit the speeds to a level that will not quite overload the router, and then use QoS against your artificially-low speed limit.

Gave it a shot and with using the Simple Queues section (under Queues) and only managed about 140mbit. That’s pretty low :slight_smile: The switch hardware queues did better (no surprise there) but I’m not sure how congestion would work with the switch-based QoS as I’m more familiar with the Linux software queues.

Oh well. Ended up that I can pick up a 1009 sooner than I thought so I can probably “deal” with only 325mbit for a few days :wink:

Have you tried fasttrack?

http://wiki.mikrotik.com/wiki/Manual:Wiki/Fasttrack

you use a 1gbit connection only for your laptop??

Oh wow I didn’t know about fast-track. That’s pretty neat!

In any case, I have the CCR1009 all setup. I’m still tweaking things (such as installing a VPN client) so I’m not quite yet at a good benchmark for my setup, but it so far seem to have no problem handling the gigabit uplink, even when underclocking it (though I found that didn’t help reduce heat or power by all that much so I’ll probably set it back to stock).

My CRS109 is still involved, but is now largely just a switch. I had though about maybe having it handling secondary services (DHCP, DNS, VPN) but for now it’s mostly functioning as switch and my wireless bridge.