Why enable hn ALTQ Support ?

[jc1976]

This one's been bugging me and i'm hoping someone will explain it to me.

I read all over how this option should be left enabled however i don't understand why?

if i'm running pfsense on a bare metal machine with an intel nic, why would i want to leave this enabled?
I interpret that description as saying it's necessary when used on a hyper-v but if on bare metal, it's going to be more performant if disabled.

Can anyone explain this?

Thanks!

[DaddyGo]

@jc1976 said in Why enable hn ALTQ Support ?:

Can anyone explain this?

Hi,

if you don't want to create (apply) traffic shaping (on BM), leave it as it is, or as it is written:

https://docs.netgate.com/pfsense/en/latest/trafficshaper/altq-hardware-support.html

BTW:
Intel NICs usually handle this well, but it is not relevant here

[jc1976]

@daddygo I guess i just don't understand the way it's described..

"*hn ALTQ Support

Checking this option will enable support for ALTQ traffic shaping on hn(4) network interfaces in Hyper-V.

For ALTQ to work on hn(4) interfaces, the operating system must disable the multi-queue API which may reduce the system capability to handle traffic. The administrator must decide if this reduction in performance is worth the benefit of traffic shaping.*"

In my mind, this tells me:

1. "enabling ALTQ traffic shaping" we're also "disable the multi-queue API"..

2. when we "disable the multi-queue API" , we're reducing the system capability to handle traffic......
   which, while undesirable, is a necessary trade-off if we want/need to run pfsense in a hyper-v setup..

so my question is; how is this a good thing?

The way it's worded seems to say if pfsense is run on bare metal, it is better to NOT enable hn(4) ALTQ support, and let it in fact run said multi-queue API..

What am i missing/not getting here?

I apologize for being so particular. Hopefully one of these days i'll get to know this well enough to where i can contribute to others in my same situation.

Thanks all!

[DaddyGo]

@jc1976 said in Why enable hn ALTQ Support ?:

What am i missing here?

Now you see the difference between a real environment and a virtualized environment

This used to be an issue, now it is not, if we are talking about a compatible card.....

https://redmine.pfsense.org/issues/7066

You cannot get rid of the question even if you use VLANs

BTW:
but you wrote that you run on BM and I hope you have enough bandwidth, so don't shape the traffic because there is no point :)

[jc1976]

@daddygo Hey, just seeing this.. thanks for the reply.

interestingly enough, i came across the whole "fq_codel" thing and started messing around with it.

low and behold, it (seemingly, at least to my novice senses) made a very significant difference with my latency.

going through the bufferbloat test from waveform, initially my unloaded ping was about 10-12ms, and once it started the upload and download tests, my latency was up around 60+ms and i was graded as a C.. i followed some instructions and then messed around with it to adapt it to my particular internet speed (120x6) and my upload/download latency dropped to about 5ms for both upload and download. I can definitely tell the difference (no lagging) when someone else is video conferencing while i'm on my workstation, streaming whatever..

anywho, are you saying that disabling the hn(4) ALTQ support will improve it further?