ACC Ping not low enough?

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usergar
Posts: 18
Joined: Thu May 29, 2014 6:58 am

ACC Ping not low enough?

Postby usergar » Thu May 29, 2014 7:10 am

Hi, I've been playing with OpenWRT/Gargoyle for a few weeks now, and decided to get QOS up and running. Basically I have 3 categories of traffic:

Priority: Video streaming through a proprietary IPTV box. BW minimum set to 2500kbps

Normal: Web Browsing

Low Priority: Torrents/Usenet

Basically when I start downloading things, "Priority" bandwidth shrinks and the IPTV stream stutters like crazy. It needs about 1500kbps minimum, and I will see it hit about 200 to 300 kbps during Usenet/Torrents.

I think this is due to ACC not working for me. When it is set to my ISP's gateway, I get about 15ms during idle. During full load, it only jumps up to maybe 20ms, maybe up to 30 for a moment or two, and the "Ping Limit" gargoyle sets is around 50/60 if I recall. This is too high even if RTT is enabled (enabling it does not help the issue, but I don't want to enable it anyway). From what I've read, the "Manually control target ping time" setting is only for the difference between RTT and non-RTT, and it appears to have a minimum value of 10, and so it doesn't help me in this case.

Any ideas? Am I just using things wrong? I've tried setting the ping IP to OpenDNS as suggested elsewhere, and that increases my idle ping to about 30, but the "Ping Time Limit" is also increased, so it's the same problem.

So from what I gather, ACC does not enforce QOS until that 2nd number in the brackets in "Ping Time Limit" is reached? Can I modify this? Is this even the problem? Is my internet so amazing that under maximum load the ping is largely unaffected? (Doubt it haha)

Any help is appreciated, I'm loving this project otherwise! Thanks!
Last edited by usergar on Thu May 29, 2014 8:34 am, edited 1 time in total.

usergar
Posts: 18
Joined: Thu May 29, 2014 6:58 am

Re: ACC Ping not low enough?

Postby usergar » Thu May 29, 2014 8:34 am

I should add, my practical line speed is about 16mb/1mb, upload QOS is set sanely, and when I say max load/torrents/usenet, the number of connections can be low-- I can set usenet to 10 connections, which maxes the line. Hardware is 1043ND v2.2, Gargoyle 1.6.1 and modem in bridge.

pbix
Developer
Posts: 1365
Joined: Fri Aug 21, 2009 5:09 pm

Re: ACC Ping not low enough?

Postby pbix » Thu May 29, 2014 12:33 pm

Some errors in your understanding I will correct.

The job of ACC is to detected changes in the performance of your link to the internet. It is the nature of QoS that is must know the peak through-put the link will support and it is a fact that most WAN links vary in performance. ACC can handle this situation.

But ACC does not itself cause QoS to operate or not, the enable QoS switch on the QoS page does this. If ACC is not enabled QoS just used the number you put in as your downlink speed. As long as this is less than the actual speed you are getting at the moment QoS will work fine.

When active ACC switches between the two ping time targets shown in the status section based on if a MinRTT class is active or not. You can influence these two target values with the manual setting.

I think in your case you should disable ACC and set the download speed to 10Mbps down. Get that working and then move onto using ACC.

Remember QoS does not do anything unless the link is fully saturated. Make sure to report results only for this case.
Netgear WNDR3700v2
TP Link 1043ND v3
TP-Link TL-WDR3600 v1
Buffalo WZR-HP-G300NH2
WRT54G-TM

usergar
Posts: 18
Joined: Thu May 29, 2014 6:58 am

Re: ACC Ping not low enough?

Postby usergar » Thu May 29, 2014 5:53 pm

Hi pbix, thanks for clearing some things up.

If I set the QOS downlink figure to 10mbps with ACC off (my modem's page reports a little over 17.5mbps, and I read gargoyle accounts for overhead) it works OK, but ofcourse overall download speed suffers. But the way ACC works, even if I put my speed as 100mbps, it should still limit the link speed to ~17mbps due to the high pings it *should* reach around that speed, no?

Probably a dumb question, but does ACC try to check for congestion on my own downlink/uplink speed or the ISP's network in general?

So ultimately it looks like my ISP gateway/OpenDNS ping is barely higher than idle when I am maxing out the line, which means ACC is not limiting my line speed, which means QOS is never applied? Is that right? Any way to remedy this?

pbix
Developer
Posts: 1365
Joined: Fri Aug 21, 2009 5:09 pm

Re: ACC Ping not low enough?

Postby pbix » Fri May 30, 2014 10:26 am

ACC checks for congestion between your router and the ping target IP address shown in the ACC section.

I have updated the Wiki to address you other questions. Please look there.
http://www.gargoyle-router.com/wiki/doku.php?id=qos&#active_congestion_controller_acc
Netgear WNDR3700v2
TP Link 1043ND v3
TP-Link TL-WDR3600 v1
Buffalo WZR-HP-G300NH2
WRT54G-TM

usergar
Posts: 18
Joined: Thu May 29, 2014 6:58 am

Re: ACC Ping not low enough?

Postby usergar » Fri May 30, 2014 12:27 pm

Thanks, that did clear some things up for me. So is there anything I can do about this? Am I simply cursed with this supernatural ping that won't go up? Anything other than OpenDNS or gateway IP? I tried a tracert to OpenDNS and picked the IP that showed the biggest jump-- no better than OpenDNS itself, unfortunately!

usergar
Posts: 18
Joined: Thu May 29, 2014 6:58 am

Re: ACC Ping not low enough?

Postby usergar » Fri May 30, 2014 8:58 pm

Another issue I've noticed is that when I'm watching a multicast stream (from my ISP) it appears to get bandwidth from "nowhere". As in, my max bandwidth while torrenting/usenet is say 15 mbps, I never see it get higher. If i then start watching a multicast stream, an extra 2.5 mbps comes out of nowhere and now my max speed is 17.5 mbps. This 17.5 mbps load is not attainable unless I'm watching this particular type of stream. Any regular streaming Youtube etc doesn't bump it up. Would there be a way to create a class for this traffic and have the QOS "ignore" it, and not count it towards the bandwidth?

In the meantime I've tried other IP addresses for the ping limit, including amazon/other ISP's gateway IP addresses, and again, the ping increase is too small (though it is there).

usergar
Posts: 18
Joined: Thu May 29, 2014 6:58 am

Re: ACC Ping not low enough?

Postby usergar » Mon Jun 02, 2014 4:22 am

In addition, I have noticed that QOS throttles my bandwidth for no reason when only 1 class has traffic? Is that supposed to happen? This is with ACC disabled.

Eg. I set "Total Download Bandwidth" to 13 mbps (found this is best for streaming IPTV), and my Usenet runs at 1.4 MB/S. I up the value to 18mbps, and Usenet jumps to 1.7 MB/S. There is no other traffic on the network, the QOS distribution is 100% to the correct class, and ofcourse the Usenet traffic is all in that one class. Any ideas?

pbix
Developer
Posts: 1365
Joined: Fri Aug 21, 2009 5:09 pm

Re: ACC Ping not low enough?

Postby pbix » Mon Jun 02, 2014 12:18 pm

Except for enforcing maximum bandwidth limits QoS does not do anything unless your link is saturated.
Netgear WNDR3700v2
TP Link 1043ND v3
TP-Link TL-WDR3600 v1
Buffalo WZR-HP-G300NH2
WRT54G-TM

usergar
Posts: 18
Joined: Thu May 29, 2014 6:58 am

Re: ACC Ping not low enough?

Postby usergar » Mon Jun 02, 2014 8:12 pm

I have no maximum bandwidth limits set-- this issue is testable. Disable ACC, saturate your connection, ensure it is the only class that is active, and set your "Total Bandwidth" to a low value than it normally is. The speed of your downloads should not change, but they definitely do.


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