Question Why is my 802.11ac capped at 54mbps

[StampyDriver]

I am having trouble understanding why receive speed should be so much lower than transmit.

Link Speed (receive/transmit): 54/780 (Mbps)

SSID: Morgana5
Protocol: Wi-Fi 5 (802.11ac)
Security type: WPA2-Personal
Network band: 5 GHz
Network channel: 40
Link speed (Receive/Transmit): 54/780 (Mbps)
IPv4 address: 192.168.0.108
IPv4 DNS servers: 192.168.0.1
Manufacturer: TP-Link Technologies Co., Ltd.
Description: TP-Link Wireless USB Adapter
Driver version: 1030.22.405.2017
Physical address (MAC): D0-37-45-8C-2C-4E

I am connecting to a freshly installed access point which is set up to 5Ghz only and WPA2-PSK (AES) encryption.

I cannot get any download speed from my server connected to the same AP over around 5MB/s.

This a new AC1900 USB adaptor on the client, and cannot find any way of increasing the download speed to anywhere near the upload speed.

Any ideas?

Thanks

 

[vov4ik_il]

What kind of 802.11 interface does the server have? Is the access point letting you talk directly to the server (client isolation off)?

 

[StampyDriver]

What kind of 802.11 interface does the server have? Is the access point letting you talk directly to the server (client isolation off)?

The server is a raspbery pi 4 - Both the raspberry pi and my desktop are the only 2 clients connected. The pi shows it's connected to 5G but I can't find the command to determine if it's connected with N or AC.

 

[vov4ik_il]

iwconfig
Bit Rate is what you want to know...

/home/pi/.config/vlc$ iwconfig
eth0      no wireless extensions.

lo        no wireless extensions.

wlan0     IEEE 802.11  ESSID:"AV1A70R"
          Mode:Managed  Frequency:5.785 GHz  Access Point: 88:B1:E1:BE:D3:20 
          Bit Rate=263.2 Mb/s   Tx-Power=31 dBm 
          Retry short limit:7   RTS thr:off   Fragment thr:off
          Power Management:on
          Link Quality=60/70  Signal level=-50 dBm
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:117  Invalid misc:0   Missed beacon:0

Ehm, the Pi might be slow to read the files too.

 

[StampyDriver]

No, I plugged in a physical cable and checked that. Got over 10 times the bandwidth so I know it can read the files fine.

The server does say

wlan0 IEEE 802.11 ESSIDff/any
Mode:Managed Access Point: Not-Associated Tx-Power=31 dBm
Retry short limit:7 RTS thrff Fragment thrff
Encryption keyff
Power Managementn

What does it mean by Access Point Not Associated? The PI desktop WIFI icon shows the access point I wanted.

 

[vov4ik_il]

Remove the wireless profile and create it manually.

 

[DeauteratedDog]

Do you have WMM disabled? When disabled, data rates are limited to a/g rates (54 Mbps).

 

[StampyDriver]

Do you have WMM disabled? When disabled, data rates are limited to a/g rates (54 Mbps).

The access point doesn't offer me that option.

 

[StampyDriver]

Remove the wireless profile and create it manually.

I will look into that. Thanks.

 

[StampyDriver]

Ok, so tried disabling the 5G and going with 2.4G

SSID: Morgana24
Protocol: Wi-Fi 4 (802.11n)
Security type: WPA2-Personal
Network band: 2.4 GHz
Network channel: 1
Link speed (Receive/Transmit): 54/195 (Mbps)
IPv4 address: 192.168.0.108
IPv4 DNS servers: 192.168.0.1
Manufacturer: TP-Link Technologies Co., Ltd.
Description: TP-Link Wireless USB Adapter
Driver version: 1030.22.405.2017
Physical address (MAC): D0-37-45-8C-2C-4E

Same - still says Receive speed is 54

 

[DeauteratedDog]

Because 54 Mbps is the top rate for 802.11a (5 GHz) and 802.11g (2.4 GHz), I am suspicious of a configuration problem, probably on the AP.

I would love to look at a packet capture. Do you know how to use tcpdump?

 

[StampyDriver]

Because 54 Mbps is the top rate for 802.11a (5 GHz) and 802.11g (2.4 GHz), I am suspicious of a configuration problem, probably on the AP.

I would love to look at a packet capture. Do you know how to use tcpdump?

never used tcpdump.

I did change to a totally different access point (RT-AC87U) with factory reset it. Apart from getting a higher transmit speed, the (pretty decent) receive speed stays the same.

SSID: Merlin5
Protocol: Wi-Fi 5 (802.11ac)
Security type: WPA2-Personal
Network band: 5 GHz
Network channel: 100
Link speed (Receive/Transmit): 54/1170 (Mbps)
IPv4 address: 192.168.0.108
IPv4 DNS servers: 192.168.0.1
Manufacturer: TP-Link Technologies Co., Ltd.
Description: TP-Link Wireless USB Adapter
Driver version: 1030.22.405.2017
Physical address (MAC): D0-37-45-8C-2C-4E

I think that rules out the AP. I will have to try my daughter machine and see if it says the same.

 

[StampyDriver]

never used tcpdump.

I did change to a totally different access point (RT-AC87U) with factory reset it. Apart from getting a higher transmit speed, the (pretty decent) receive speed stays the same.

SSID: Merlin5
Protocol: Wi-Fi 5 (802.11ac)
Security type: WPA2-Personal
Network band: 5 GHz
Network channel: 100
Link speed (Receive/Transmit): 54/1170 (Mbps)
IPv4 address: 192.168.0.108
IPv4 DNS servers: 192.168.0.1
Manufacturer: TP-Link Technologies Co., Ltd.
Description: TP-Link Wireless USB Adapter
Driver version: 1030.22.405.2017
Physical address (MAC): D0-37-45-8C-2C-4E

I think that rules out the AP. I will have to try my daughter machine and see if it says the same.

Thats odd, my daughter computer have the "Link speed" line in the dialog box

 

[vov4ik_il]

I would say there is a 802.11g device (or support) that reverts everybody to that mode. Turn .11g off in the router and see what that does.

 

[StampyDriver]

I would say there is a 802.11g device (or support) that reverts everybody to that mode. Turn .11g off in the router and see what that does.

Same. There are only 2 devices connected via wifi to the router.

 

[StampyDriver]

Ok, so on the router I found a status screen which was telling my pc was connected at over 500Mbps so I think the other value is incorrect.

I think the issue is the raspbery pi only has a transmission rate for 135mbps. I am not sure how to tell it to use AC. Will try in a rasperry pi forum.

Thanks everyone for the help.