Wireless speed: download slower than upload

[patrashov88]

Hello!

After long thinking I really want to understand the reason for behavior bellow.

Many times when I test wireless speed I notice that download speed to client slower than upload from client to Access Point.

Most of the time I try it in Cisco infrastructure and speedtest.

Today I test Cisco 1852 managed by 3504.

Download speed ~90 Mbit/s, Upload ~ 140 (5GHz, 40MHz channel, 2 SS client).

I tested different scenarios: distance to AP and two different client. PC and Smartphone.

Speed Test result does not metter, I only think about results that every time speed TO client slower than speed FROM client to AP.

I continue my test at home where I have 1SS Wireless router 802.11n.

Download speed ~20Mbit/s, Upload ~30Mbit/s (from both - mobile and PC I had this difference)

I connect my PC by wire (in the same place). There is no difference in download/upload speed.

Than I try test with jPerf.

One PC I connect by wire to my network, another - by wireless.

Download speed to Wireless PC was 50 Mbit/s, UPLOAD - 80Mbit/s.

So, I think that results of my tests shows that the cause of problem not in wired network. The cause of problem in wireless phisical.

Is there anybody who could explain me the real reason of this download/upload difference?

Before I make test with my home router I thought that the reason is MRC function that helps cisco AP to combine signal from client hence the speed faster.

But my home router is old and does not support MRC, it is 802.11n 1ss.

My only one idea that this difference due to more sencitivy antenna that has router.

Help me, I could not sleep  

Thank you!

[Scott Fella]

When you want to test your wireless, only use iperf. Don’t look at speed test because that also introduce variables from your router and the internet. My test from using iperf has a +- 10-30Mbps either direction.

[patrashov88]

Thank you, Scott! I understand that Speedtest could give not real and distorted results.

But I tested with iPerf in my local network and every time DOWNLOAD to wireless client was ~30-50% slowly than UPLOAD from client to AP. In different environment (cisco and home Zyxel)

So, the real reason I think not with speedtest behaviour.

Thank you!

P.S. Buy the way Speedtest on the same place via wire shows me ~same DOWNLOAD/UPLOAD results

[Scott Fella]

I’m just saying that your best test is Iperf as that shows your internal network. Speedtest is when you are fine with what you are seeing with internal speeds and want to test the isp speeds. I run multiple types of Cisco controllers, and Meraki and like I mentioned, I have a 10-30 Mbps difference at times. It’s never the same, so I don’t really worry about it.