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kaila

join:2000-10-11
Lincolnshire, IL
reply to hackybag

Re: Big downloads ruin voice quality despite QOS

I hope you get this nailed, but in the past I've made improvements but never achieved perfect success with QoS on various consumer routers using either DD-WRT or Tomato when there was high network load.

The best QoS solutions that I've tried and found to work reliably well with VoIP are pfSense and Mikrotik. The downside of course are the learning curves, but if you have the time and inclination, it works very well.

lifespeed

join:2009-09-08
reply to hackybag
The short answer is you don't have the setup right. It is also true that very few routers do inbound QoS correctly, if at all. Yes, it exists and does work despite all the naysayers with limited understanding claiming "you can't control incoming".

I only have direct experience with Draytek Vigor 2130, an excellent consumer router with bidirectional QoS. This is an inexpensive yet high-performance consumer router you can get for around $100. Other options which I am not familiar with are PFsense and monowall. I have heard from Tomato and DD-WRT proponents, but I get the impression these are fragmented solutions that run on antiquate hardware.

Good luck sorting it out. It CAN be done.
--
Lifespeed

mdseuss

join:2012-05-27
Worcester, MA

1 recommendation


To be a pedantic naysayer, you CANNOT do true QoS without control of BOTH ENDS of the link that has the bottleneck (the consumer spigot).

Yes you can achieve nearly wonderful things with traffic shaping and "consumer grade Qos" settings, but you are really just herding reasonably well behaved applications to avoid them stepping on each other.

lorennerol
Premium
join:2003-10-29
Seattle, WA
said by mdseuss:

To be a pedantic naysayer, you CANNOT do true QoS without control of BOTH ENDS of the link that has the bottleneck (the consumer spigot).

Yes you can achieve nearly wonderful things with traffic shaping and "consumer grade Qos" settings, but you are really just herding reasonably well behaved applications to avoid them stepping on each other.

+1

If your ISP has you throttled to 5mbit, the bottleneck is on their gear, not at your router.

lifespeed

join:2009-09-08
reply to mdseuss
said by mdseuss:

To be a pedantic naysayer, you CANNOT do true QoS without control of BOTH ENDS of the link that has the bottleneck (the consumer spigot).

You do have control of both ends of the spigot. The router, with proper QoS implementation, delays ACK of incoming packets causing the sending server to slow down.

I have had this setup for years and have tested it with large FTP transfers in both directions, bittorrent and other downloads. I know it works. It sounds like you have never done this, at least correctly with capable hardware. So who should we believe? Somebody who failed to get it to work, or somebody who has?

I am becoming bored with having this same discussion over and over again trying to inform the (apparently) unwashed masses. Like I said, this is a commonly held misconception that many people subscribe to.
--
Lifespeed

mdseuss

join:2012-05-27
Worcester, MA

1 recommendation


Sorry, read some RFCs

You are stuck in "consumer grade" folklore.

lifespeed

join:2009-09-08
said by mdseuss:

Sorry, read some RFCs

You are stuck in "consumer grade" folklore.

LOL. First, the Draytek 2130 is a SMB-grade router at a consumer price, not your typical drek you find at the big box store.

Second, I do not speak about folklore, but from empirical evidence and testing. You are just throwing around wild accusations, while I have experience and hard data to back up my statements.

Just because you have never seen it work, don't know how to figure it out, or don't have the right hardware doesn't mean it doesn't exist.
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Lifespeed

lifespeed

join:2009-09-08

1 edit
reply to mdseuss
said by mdseuss:

You are stuck in "consumer grade" folklore.

said by Cloneman:

You're doing it wrong - but that's okay, pretty sure everyone in the world is doing it wrong . . . You need a version of tomato that implements proper downstream QoS, which uses a global limit for inbound.

Latest Toastman is the version i've tested to work. I believe other firmwares, like recent shibby versions, also implement Tiomo's QoS rules which are the key to proper downstream bandwidth management.

You can read some of my findings here:
»Cloneman's Tomato QoS Tips for adsl, vdsl2, and cable

Later in thread I highlight how to test your setup with visualware voip tester

said by kaila:

The best QoS solutions that I've tried and found to work reliably well with VoIP are pfSense and Mikrotik. The downside of course are the learning curves, but if you have the time and inclination, it works very well.

If you read this thread, you will notice a couple other posters using REAL routers that have had the same success I have seen. But why listen to actual experiences when you can just make unsupported statements about inbound QoS not working?
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Lifespeed

lifespeed

join:2009-09-08
reply to lorennerol
said by lorennerol:

If your ISP has you throttled to 5mbit, the bottleneck is on their gear, not at your router.

Your router can decide which traffic has priority to use the available 5 Mbits in your example. If you have the right router.

In almost all cases your ISP network is not saturated or overloaded, only the last mile link to your house is limited in speed. A good router manages this in both directions, given proper configuration.
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Lifespeed

mdseuss

join:2012-05-27
Worcester, MA

1 recommendation


Doesn't matter what kind of router you have. If don't control BOTH ENDS (and hence the middle) of the "thing that needs QoS", then you aren't doing REAL QoS.

This isn't "wild accusations". Just simple networking and perhaps queue theory.

lifespeed

join:2009-09-08
said by mdseuss:

Doesn't matter what kind of router you have. If don't control BOTH ENDS (and hence the middle) of the "thing that needs QoS", then you aren't doing REAL QoS . . .

Now you're repeating yourself. Done here . . .
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Lifespeed

Bink
Villains... knock off all that evil

join:2006-05-14
Castle Rock, CO
kudos:4
Reviews:
·VOIPO

1 recommendation

reply to lifespeed
Sorry, but I have to concur with mdseuss See Profile completely here. Even with my first post in the thread mentioned doing QoS in both directions, I also noted inbound QoS is less effective. At the end of the day, inbound QoS here is only best effort and not ideal—and, depending on one’s traffic patterns, success is variable.

While others in this thread have shared their experiences, the fact of the matter is someone else is making the decision whether to drop packets or not before your QoS device even sees the packets—and while you can have some effect on this, the solution is still not ideal and this is why businesses invest in costly MPLS networks, with guaranteed bandwidth and QoS, to connect their offices (as opposed to just doing everything over the Internet and wrapping it up via IPsec).

For what it’s worth, I do technology consulting for a living and some of this deals with building business-class data networks.

lifespeed

join:2009-09-08
said by Bink:

Sorry, but I have to concur with mdseuss See Profile completely here. Even with my first post in the thread mentioned doing QoS in both directions, I also noted inbound QoS is less effective. At the end of the day, inbound QoS here is only best effort and not ideal—and, depending on one’s traffic patterns, success is variable.

While others in this thread have shared their experiences, the fact of the matter is someone else is making the decision whether to drop packets or not before your QoS device even sees the packets—and while you can have some effect on this, the solution is still not ideal and this is why businesses invest in costly MPLS networks, with guaranteed bandwidth and QoS, to connect their offices (as opposed to just doing everything over the Internet and wrapping it up via IPsec).

If you want to prove that just using the internet and QoS in some rare cases does not work as well as a dedicated private network, I suppose that would be possible.

I don't think that is what anybody is interested in here, and arguing about some obscure 0.01% of use cases is not relevant to this discussion. We all use the internet for VoIP and other uses, and are trying to accomplish PSTN-grade audio quality, or better. This is absolutely possible using hardware available today.

Is it possible that there exists some use case that would break my QoS implementation and cause VoIP packets to drop or delay? Perhaps, but I have not run across this in years of use. Nor have other users with proper setups. Arguments about rare corner cases, while possibly technically correct, are not germane.
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Lifespeed

phoneuser

join:2012-12-19
New York, NY
reply to Bink
I'm sorry too, but I in turn have to disagree completely with mdseuss See Profile and Bink See Profile here. RFCs and MPLS and "real" QOS and queue theory notwithstanding, the fact is that the control that pfSense and m0n0wall and Tomato (and others) give you over inbound TCP streams can greatly improve the V0IP experience. Yes, we know that it's throttling the far endpoints by dropping already-transmitted packets, therefore not sending ACKs for those packets, and thereby causing the far endpoints to back off. Yes, it's effective only in limiting TCP streams, not UDP (unless there's some other higher-level throttling). Call it "crude traffic shaping" or "a side-effect of TCP congestion control" if you want. I agree that it's important to understand how it works and what its limitations are, but that doesn't mean it isn't useful in practice (I know that it is for me) or that people shouldn't use it or at least try it in the absence of something fancy that in any case isn't available to them.

mdseuss

join:2012-05-27
Worcester, MA

Neither Bink nor I said 'consumer grade QoS' wasn't helpful. And noone is saying anyone shouldn't use it.

It just isn't a complete and proper QoS implementation.

It's good enough for consumer traffic to keep your VoIP and your porn generally at peace with each other.


xyar
Premium
join:2001-06-21
Portland, OR
reply to hackybag
So here's a question - Would a Cisco 4506-E layer 4 switch be able to effectively control QoS on inbound data? I just bought one and that's what I'm hoping.
--
One geek to rule them all!

mdseuss

join:2012-05-27
Worcester, MA

I suspect any recent Cisco will have all manner of traffic shaping commands for you. My eyes glaze over looking at Cisco IOS commands and examples. Since you are perhaps getting a metro ethernet type service delivered from a provider that does all manner of internal QoS, you should check with them if there are special ways you can play along with QoS they may be doing (or they may just be doing it for you prior to dumping traffic on your side).

If you are just doing QoS 'standalone' on your router, trying to shape traffic, then you are subject to the same limitations of trying to control traffic coming your way from "out there".

Even with a fancy Cisco, this is still "one-armed QoS" and not real end-end QoS.

One-armed QoS ... I like it. I coined a term.


mozerd
Light Will Pierce The Darkness
Premium,MVM
join:2004-04-23
Nepean, ON

2 edits
reply to hackybag
Click for full size
Traffic Classes
QoS is a complicated topic and means different things to different people and devices.

The key aspect of Bandwidth Management is allocate bandwidth to classes of traffic based on the number of users and how the users use their allocations based on the rate of concurrency sequentially done.

For example the ZyWALL USG 100 provides very good Bandwidth Management capability. The Graphic above shows one example of the Traffic Classes that can be effectively managed with this device.

What is IMPORTANT to note is how the ZyWALL USG 100 classifies each service and the DiffServ PRIORITY weight that is attached.

For example:
SIP is assigned a 1
Video Conferencing is assigned a 2
Video Streaming is assigned a 3
HTTP, SMTP, POP3 are assigned a 4.
FTP assigned a 5

This approach works really well for me in many instances.

If you want to learn more the following link to the User Guide for the USG 100 would be helpful.
»ftp://ftp.zyxel.com/ZYWALL_USG_100/use···_Ed1.pdf

Page 104 is where the graphic shown in this post is taken from.
--
David Mozer
IT-Expert on Call
Information Technology for Home and Business


hackybag

@rr.com
reply to hackybag
For some inexplicable reason, QOS now works. I have Tomato set to cap what is apparently a 15/1 line to 14000/900 and each category (VoIP, DNS, WWW, other) to 25% min/ 95% max.


mozerd
Light Will Pierce The Darkness
Premium,MVM
join:2004-04-23
Nepean, ON
said by hackybag :

For some inexplicable reason, QOS now works.

Glad that it now works for your but inexplicable reason is not a good thing.


hackybag

@rr.com
reply to hackybag

Try turning it off and on again

Well, the modem was remotely rebooted the same day I organized my equipment (and therefore power cycled the router). So one of those reboots could have resolved the issue.