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Valid reasons to use Smart Queue?

Just curious as to usage scenarios that might benefit with the use of SmartQueue? As with many features, there is something of a lack of information as to the types of real-world situations that would call for SmartQueue (or information regarding when it might be detrimental). I realize there is a lot of just "try it a see" when it comes to features like this, but some guidance wouldn't hurt. I've played with it a bit, and it definitely functions to reduce the bandwidth of a single device that's trying to utilize all the WAN bandwidth, but according to our Dashboard we almost never see high WAN utilization in the first place.


Here are a couple possible usage scenarios:


1) 5 teachers, all using Netfilx at the same time (this will never happen, but it is a good "for instance")

2) 35 students simultaneiously taking a web-based test - (continious low-bandwitch connection for each device with intermittent spikes at random intervals as each student (at their own pace) submits an answer and the browser loads the next question)


Would SmartQueue be beneficial or detrimental in either of those situations?

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Re: Valid reasons to use Smart Queue?

Hello @waldengreen,


There would be a use if you were using VoIP or when you have a really slow internet connection.




Glenn R.

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Re: Valid reasons to use Smart Queue?

Your best bet is to read here. 

Video (the Netflix scenario)
Playing onlime games etc. 
These types of service are called
inelastic, meaning that they require a certain minimum bit rate and a certain maximum latency to function.

By contrast,
elastic applications can take advantage of however much or little bandwidth is available. Bulk file transfer applications that rely on TCP are generally elastic.

So Smart Queue will/should prioritise the inelastic applications at the cost of the elastic ones. 

5x Teachers watch Netflix get higher priority than the teacher copying kids test results to a server. 

Obvioulsy if you have sufficient bandwidth and low latency, it won't do much if any good. 

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Re: Valid reasons to use Smart Queue?

At campgrounds that have wifi for campers the smart queue feature is a must for fair sharing the bandwidth with all clients regardless of who is trying to hog the connection.


On a cable setup where we have 65 Mbps down and 6 Mbps up, if 4 or 5 campers at the end of the day after taking pictures all day have their iphones all start uploading all of their several gigabytes of videos to the cloud, it can saturate that 6 Mbps upstream in no time.  When that happens, people just surfing or whatever -- it will act like the connection is not working at all w/o the smart queues in place to give the "bursty" web sites being loaded and e-mail checking, surfing facebook etc. to get a chance.


It also helps when several people are trying to stream in the downstream direction -- it will always fair share the available bandwidth to all clients.  I find it to be a much better solution rather than bandwidth limiting groups of wireless users etc. 


When the campground is mostly empty, the few people that are there can enjoy having the full bandwidth they can get.  If they were limited to like 3 Mbps down and 0.5 Mbps up, that's fine, but just letting the smart queues manage it gives everyone a better experience for when the campground is crowded vs. hardly anyone around.


Hope this helps!


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Re: Valid reasons to use Smart Queue?

Tell us a) the USG or EdgeRouter model you have and b) the speed of your Internt uplink, and c) the UniFi model of your APs.


The best QoS approach is to have more bandwidth than needed --> no SmartQueue necessary


You can actually read up yourself on the QoS traffic shaping limits of the different USG & EdgeRouter hardware. Note that these limits you will find here in the forum refer to down & up traffic combined, i.e. the sum of both!


In case of the UAP-AC-HD or better you could enable "airtime fairness" instead of SmartQueue. All other APs have too weak a CPU for that feature.