Configuring QoS on a Edge Switch 48 Lite
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@dustinb3403 said in Configuring QoS on a Edge Switch 48 Lite:
@JaredBusch you've obviously never seen QoS at the Port level for every switch having same exact settings and having to deal with that headache.
Lots of people don't know WTF they are doing and set shit up wrong. That does not invalidate the thing they were setting up. Only their implementation of it.
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@romo said in Configuring QoS on a Edge Switch 48 Lite:
Don't have any vlan set on the the switches, so probably best bet would be
Class of Service->IP DSCPthen right?Yes. Change all the interfaces to trust IP DSCP first. Before you fuck wit the default priorities.
But you do still want to look at verifying saturation.
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@jaredbusch "Lots of people don't know WTF they are doing" Im sometimes one of those people. But I think the problem is due to a lack of proper explanation, training materials and scenarios. Not talking about you specifically but saying in general.
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@krisleslie said in Configuring QoS on a Edge Switch 48 Lite:
@jaredbusch "Lots of people don't know WTF they are doing" Im sometimes one of those people. But I think the problem is due to a lack of proper explanation, training materials and scenarios. Not talking about you specifically but saying in general.
Which is what I was getting at. Setting QoS isn't the fix, tag the traffic you want and set the priority for just that traffic type, not for everything.
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Like for me I'd have to "see" why it isn't the option and the fallout for making a bad decision. I'm a bit of a visual and reader type learner.
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@dustinb3403 said in Configuring QoS on a Edge Switch 48 Lite:
@krisleslie said in Configuring QoS on a Edge Switch 48 Lite:
@jaredbusch "Lots of people don't know WTF they are doing" Im sometimes one of those people. But I think the problem is due to a lack of proper explanation, training materials and scenarios. Not talking about you specifically but saying in general.
Which is what I was getting at. Setting QoS isn't the fix, tag the traffic you want and set the priority for just that traffic type, not for everything.
No, that is not what you were saying.
You were clearing saying thart QoS was useless and had no point.
Also, it is not possible to set priority for only one thing. By setting a priority at all, you automatically create a base priority level and then prioritize above that.
You simply cannot have a priority at all if you do not prioritize everything. That is how it fucking works.
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See for me I don't understand when and where to apply QoS. As one minute your told it's useless the other it's useful. Like what's missing is the context behind the usage. I agree with Jared in that if your enabling it, by that alone it doesn't mean something magical is happening, something specific is.
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@jaredbusch Would the steps be something like this:
- Change the interface configuration to trust IP DSCP,
- Give IP DSCP 46 (Rtp) a traffic class of 7 (any other thing i'd need to set as a higher traffic class?).
- Choose the Queue management type- Taildrop (default) or WRED (any opinion on which one is better)
- Finally set the Interface Queue Drop Precedence, per interface and per queue (Don't understand this) ?
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This one of those situations I think having an AI would help.
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@krisleslie said in Configuring QoS on a Edge Switch 48 Lite:
See for me I don't understand when and where to apply QoS. As one minute your told it's useless the other it's useful. Like what's missing is the context behind the usage. I agree with Jared in that if your enabling it, by that alone it doesn't mean something magical is happening, something specific is.
You apply QoS with the intention of helping your network process traffic in the order you need it to.
The hard part is determining when and where you need to do so.
Where to start: Look for the lowest bandwidth segment and start there. In almost every network this will be the internet connection.
What you can do: You can only affect traffic passing through something under your control. This would be your devices (desktop,phone, servers,etc), switches, and router.
What you can do special note: You can only control 3 of the 4 flows on your router.
- In to router from LAN
- Out of router to LAN
- Out of router to WAN
In to router from WAN is not under your control.
Traffic on a LAN is almost never a problem because the LAN links and switching backplane are simply that fast. Contrasted with your WAN link where there is rarely enough bandwidth in both directions and also where the router processing power comes into play.
On the LAN, even if your switching backplane is not saturated, QoS can still matter because the backplane is never (almost) going to be the bottleneck. The bottleneck is the 1Gbps link to the devices. Individual ports can routinely have brief moments of saturation. Again, this is so rare that most places never need to do anything, but it is far from uncommon.
Finally, implementing QoS is not about bandwidth alone. To me, it is more about latency. Making sure important packets go out first instead of the normal FIFO order improve latency for the packets that need it and let the packets that don't care back up for a moment or two until the port unsaturates and all the packets get sent.
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@dustinb3403 said in Configuring QoS on a Edge Switch 48 Lite:
Are you able to prove that your switches are in fact saturated? Not that I don't believe you but enabling QoS doesn't really address the situation.
It's pretty certain that they are saturated. Both from monitoring AND from logical description and modeling of their network traffic. They have HIGH volume internal.
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@dustinb3403 said in Configuring QoS on a Edge Switch 48 Lite:
And QoS won't do anything for you once the call hits the open internet.
In this case, it's LAN calls with issues.
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@dustinb3403 said in Configuring QoS on a Edge Switch 48 Lite:
@krisleslie said in Configuring QoS on a Edge Switch 48 Lite:
@jaredbusch "Lots of people don't know WTF they are doing" Im sometimes one of those people. But I think the problem is due to a lack of proper explanation, training materials and scenarios. Not talking about you specifically but saying in general.
Which is what I was getting at. Setting QoS isn't the fix, tag the traffic you want and set the priority for just that traffic type, not for everything.
But the description you gave is the description of "Setting QoS". QoS for everything is another way of saying "No QoS"
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@krisleslie said in Configuring QoS on a Edge Switch 48 Lite:
See for me I don't understand when and where to apply QoS. As one minute your told it's useless the other it's useful. Like what's missing is the context behind the usage. I agree with Jared in that if your enabling it, by that alone it doesn't mean something magical is happening, something specific is.
It's EXTREMELY USEFUL in VERY LIMITED CIRCUMSTANCES.
It's like a shotgun isn't useful at the grocery store, but in the limited case of hunting, it's useful.
