Link Test results

I thought this might be of interest.

We recently set our APs to have a Download ratio to 50% seeing that our major selling point against DSL and Cable here (who sell 6 megabit connections) is the upload speed that we can offer.

I tested a link test for a SM that was a solitory session on an Advantage AP that was set at 50% download. The SM was configured to have a 4 meg download and 2 meg upload.

The result of the Linktest was 3.5 Meg down and 3.5 Meg up. I was confused at this seeing at how I had configured speeds on the SM, but I guess that what is happening is that the SM is flooding both Up and Down links to full capacity and not being an Advantage SM, this capacity is 7 Megabit aggregate which is why (seeing that the AP is at 50%) the limit i see on the LInk Test is 3.5Meg in each direction.

If anyone has more input on this, it would be interesting to hear it.

your 50% ratio would be 3.5mb up & down. so that looks completely normal.

you said the SM was configured to have a 4mb download rate & 2mb upload rate… is this the MIR settings for sustained uplink & downlink rates? you will not see that on a linktest as the airlink rates you setup are at a 50% ratio.

everything you wrote looked to be right on par with the canopy system imo.

good luck

The link test is the raw data rate between AP and SM and is determined by the AP Downlink %

The data rate set in the SM is the speed allowed to the user.

THanks guys, so my question is…

With an Advantage AP set at 50% download, would an SM set at 4 Meg download and 2 Meg Upload see those rates? They should… right?

with the AP set at 50% you would get the 3.5mb up & down that your see’n on the link tests. the MIR rate is the sustained throughput. you will need to tweak the downlink percentage to get 4mb down.

is the MIR settings for sure where you are “setting” the 4mb down & 2mb up?

Hmm, this does not make sense.

When you set the AP to be 50% down, I assume that means 50% of the available throughput ON THE AP. In this case, this is an Advantage AP with 14 megabits of throughput. Hence the AP should be able to handle up to 7 megabits of sustained downloads and 7 megabits of sustained uploads.

The Speeds that the SM sees are governed by the settings on the SM for CIR (Sustained Download and Sustained Upload). Hence with one SM on this Advantage AP, there should be NO problem for this SM to get 4 megas down and 2 megas up because the 50% on the AP limits the AP to a sustained 7 Megas up and 7 Megas down.

Where am I wrong?

CIR is committed information rate meaning you’re setting aside those speeds for the SM in question. you only want to set CIR for priority customers & giving ONE SM 4mb of CIR is not the best idea, the other SM’s on that AP would suffer.

is the SM in question a P8 radio?

when you set the AP to 50% downlink rate you are just saying that AP will give 50% of its bandwidth for downlink & 50% for uplink.

the MIR is where u set sustained & burstable rates.

The Link test always does a fully capacity test regards of the settings on the SM. Now with 8.x firmware you can have the link test use the MIR values that your set rather then flooding the link completely.

Just enable the MIR Link test setting on the Link Capacity Test Tab and it will show you the actually bandwidth the SM will do with it’s MIR values.

Advantage AP -> Advantage SM: 14Mbps sustained aggregate with 2X enabled on the AP and SM and enough S/N to keep the SM in 2X mode.

Advantage AP -> Standard SM: 7Mbps sustained aggregate/14Mbps burst with 2X enabled on the AP and SM.