Hi, hope you can get me some ideas.

I am running Jperf on two computers.


Anyone got an idea why when I do jperf test between a wired pc and a wifi connected pc the upload from the wifi connected pc is faster than the download.

Speedtest shows me the same results. I have internet connections synchron with about 100 mbit and upload is always faster than download.
So download is only about 50 Mbit while upload is about 90 Mbit.

I know the wireless "n" standard, but I have no idea why receiving is half that slow than transmitting from the wifi pc.

The wireless chip is an Atheros AR9300
Anyone got an idea?

Thanks in advance:
Arthur

There are a few things which might explain your observations:

• wireless transmission is more CPU demanding than reception ... and CPU in RB951G is no rocket
• if your RB is running decently new version of ROS, then it might be limited with Tx power ... and if client is not very close to AP, then lack of Tx power can degrade achieved throughput.
• if wireless station is verx clise to AP and AP is transmitting at high power (the official model code does include "h" for "high power"), then it may overwhelm receiver and transmission speed has to be degraded

Hopefully you can do some analysis to see if any of above mentioned possibilities might be the case.

wireless transmission is more CPU demanding than reception ... and CPU in RB951G is no rocket
if your RB is running decently new version of ROS, then it might be limited with Tx power ... and if client is not very close to AP, then lack of Tx

Checked the cpu usage, when I perform a speedtest. It is about 12 percent, so no real stressed CPU.
RB951 is about 3 Meters away from the pc. No other networks are arouind, which can harm.

As I said already. Download is much slower than upload.
Directly on the ethernet port I get 100 to 100. I really wonder what causes the slow download.

You must have some setting or other application capping your max speed over wifi connection or your transmission power isn't high enough...

The speeds shown in that screenshot are quite typical for the RB951G-2HnD.
When you are looking for high performance, get a new router with 2G+5G and AC or AX WiFi.