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slow wifi speed via 5Ghz - RBcAPGi-5acD2nD

Mon Dec 14, 2020 11:40 pm


My wifi 5Ghz interface has this config:
name="wlan2" mtu=1500 l2mtu=1600 mac-address=48:8F:5A:29:95:6F arp=enabled
interface-type=IPQ4019 mode=ap-bridge ssid="5g" frequency=auto
band=5ghz-onlyac channel-width=20/40/80mhz-eeCe secondary-channel=""
scan-list=default wireless-protocol=any vlan-mode=no-tag vlan-id=1
wds-mode=disabled wds-default-bridge=none wds-ignore-ssid=no
bridge-mode=enabled default-authentication=yes default-forwarding=yes
default-ap-tx-limit=0 default-client-tx-limit=0 hide-ssid=no
security-profile=default compression=no
On any device laptop phone i have on only 240-250Mbps download.
I verified the download uplink and i have 850Mbps dld and 250Mbps upload.
On site I saw this << Wireless 5 GHz Max data rate 867 Mbit/s >>
This AP has the capabilities to reach this speed?
Any help would be welcomed.
Thank you
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Re: slow wifi speed via 5Ghz - RBcAPGi-5acD2nD

Tue Dec 15, 2020 8:47 am

The 866Mbps is the maximum connection speed that a client can get. In the wireless registration tab you can see the speed of the connection (together with some more information). At what speed is your client connected?

There is also some tweaking to do on the settings:
  • Use fixed channel (and be aware of channel-width
  • Set Wireless Protocol to 802.11
  • Only use WPA2/AES
  • Enable WMM Support
  • Consider custom data rates (I have basic: 12 and supported: 12-54)
Hope this makes some difference. You can expect speeds up to 400-450Mbps

And please use iPerf3 for testing purposes (and not Speedtest).
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Re: slow wifi speed via 5Ghz - RBcAPGi-5acD2nD

Tue Dec 15, 2020 11:56 pm

Speedtest is the payload data rate , the indicated 867Mbps is the PHY, the physical rate of the wifi interface.
You have to take the 802.11 overhead into account, and that can be from 40 till even 75%. (450Mbps till 240 Mbps), based on packet size and the level of aggregation. (A-MSDU, A-MPDU)
Further reduction comes from retransmits (RX/TX CCQ) and % of free airtime (freq usage by others).

Some reading:
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Re: slow wifi speed via 5Ghz - RBcAPGi-5acD2nD

Fri Dec 18, 2020 4:34 pm

1.) What Wifi clients are you using? 1x1, 2x2, 20/40/80/160 Mhz support? 11an/ac/ax?
This might explain A LOT!
2.) Do they connect to 2.4G or 5Ghz
3.) You limit clients to 11ac only, that is a strange choice but ok...
4.) Country code is not set. Phones might not choose/support the (full) channel you have set there!
5.) interference with other AP!

And then as BPWL said, 868Mbps is max phy rate. Check the "wireless" -> registration tab. this shows you yhe PHY rate etc.

I like a new challenge, I migrate to ROS7... :? or maybe I am just crazy :lol: !!!

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