Goal: Compare WiFi performance for 'upload' traffic (client to AP) using a WiFi access point, a LANforge Attenuator and a LANforge Virtual Station. Traffic is generated by a RFC-2544 script on a Layer-3 UDP connection.
This demo consists of one WiFi access point and one CT523 LANforge WiFIRE machine connected to the LANforge Attenuator with coax SMA cables. (This is not over the air testing). This requires LANforge release 5.2.7 or higher.
Create Virtual Station
Select radio wiphy1 and click Modify
Set the frequency of the radio to Auto
On the Port Modify tab, click Create
Create virtual station with these paramters:
Select Wifi STA
Station ID 0
Create upstream port wired to AP
Wire the eth1 port into the upstream connection of the AP under test.
On the Ports tab, click on the eth1 port
Configure eth1 port with an upstream IP, like 10.26.2.3
Set the Gateway to the AP wired interface IP.
Create and Test Cross Connect
Go to the Layer 3 tab
Create a cross connect with these qualities:
Make sure Endpoint A is eth1
Make sure Endpoint B is sta0
Min PDU Size for both should be 1472
NOTE: These rate and PDU size settings will be manipulated by the script we setup later.
Next, expand the screen to Level 4 using the [+] button.
Configure the send buffer on Endpoint B to 1 MB
On the Layer 3 tab, click Start to verify the AP and Station can connect
Click the Display button to monitor throughput
Only a short confirmation is necessary, click Stop on the Layer 3 tab
Configure Scripting for Cross Connect
On the Layer-3 tab, click Modify
In the Level 2 box, click Endpoint A Script button
The Cross Connect Script window displays with no parameters
Select Script Type: RFC-2544. Set the following parameters:
Select Symmetric. This will increment both the A and B rates and payload sizes. (Instead of just side A).
Select Show Attenuation. This displays attenuation levels in the report.
Run Duration: 10 sec. This is how long each rate setting will be held.
Pause Duration: 2 sec. We give it some time to transition.
Max Drop Percent 10%
Max Jitter 200ms
Max RT Latency 200ms
Rates A: 56kbps. This sets the client upload target rate.
Rates B: 400Mbs. This sets the client download target rate.
Pld A: 1472 This sets the client (sta0) MTU. This is a 1500 byte wire packet.
Pld B: 9000 This sets the upstream (eth1) MTU.
Attenuator Resource: 1.1.2. You can find your attenuator resources in the Attenuator tab.
Attenuation: 0..+5..955. This is shorthand for: Begin at zero dB attenuation, increase in 0.5dB steps, until 955 dB of attenuation. Individual dB steps could also be specified.
On the Create/Modify Cross Connect window, click OK
Run the Cross Connect and Generate a Report
On the Layer-3 tab, click Start
The Scripting Report window will appear
When the script completes, you can view the graphed results.
Click on Graphical Display and a window with the graphical report will display
Scroll to the top of the window to view the graphs. Highlights are shown below.
Attenuation v. RX signal, endpoint A
Attenuation v. RX signal, endpoint B
TX rate (UDP payload) v. RX signal, endpoint B
RX rate including frame headers (UDP payload with frame headers) v. RX signal, endpoint B
RX rate v. TX link speed. You see a sawtooth pattern becuase all attenuations are included.
Click on Save File and your browser will appear the the HTML copy of the report.
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