Score:2

Ubuntu

"Low" internet speed

Никита Шейн

5/27/24, 9:50 AM

could you help, please? I have Gbit internet and when I plug in a cable without the router I have this speed (800-900), but when I connect to WiHi I have only (150-200). Could you suggest what could be the reason?

Results With Wihi: https://i.stack.imgur.com/4QtG1.png

Results With Cable: https://i.stack.imgur.com/Pu3ju.png

My Router is - TP-LINK Archer A8 This is the notebook's config:

 *-network                 
   description: Ethernet interface
   product: RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller
   vendor: Realtek Semiconductor Co., Ltd.
   physical id: 0
   bus info: pci@0000:01:00.0
   logical name: eno1
   version: 15
   serial: c8:5a:cf:db:6f:a2
   capacity: 1Gbit/s
   width: 64 bits
   clock: 33MHz
   capabilities: pm msi pciexpress msix bus_master cap_list ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd 1000bt-fd autonegotiation
   configuration: autonegotiation=on broadcast=yes driver=r8169 driverversion=5.19.0-42-generic firmware=rtl8168h-2_0.0.2 02/26/15 latency=0 link=no multicast=yes port=twisted pair
   resources: irq:16 ioport:4000(size=256) memory:52104000-52104fff memory:52100000-52103fff


*-network
       description: Wireless interface
       product: RTL8821CE 802.11ac PCIe Wireless Network Adapter
       vendor: Realtek Semiconductor Co., Ltd.
       physical id: 0
       bus info: pci@0000:02:00.0
       logical name: wlo1
       version: 00
       serial: 4c:d5:77:a2:6b:83
       width: 64 bits
       clock: 33MHz
       capabilities: pm msi pciexpress bus_master cap_list ethernet physical wireless
       configuration: broadcast=yes driver=rtw_8821ce driverversion=5.19.0-42-generic firmware=N/A ip=192.168.0.100 latency=0 link=yes multicast=yes wireless=IEEE 802.11
       resources: irq:158 ioport:3000(size=256) memory:52000000-5200ffff

upd: result ip link

 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: eno1: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc fq_codel state DOWN mode DEFAULT group default qlen 1000
    link/ether c8:5a:cf:db:6f:a2 brd ff:ff:ff:ff:ff:ff
    altname enp1s0
3: wlo1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP mode DORMANT group default qlen 1000
    link/ether 4c:d5:77:a2:6b:83 brd ff:ff:ff:ff:ff:ff
    altname wlp2s0
4: docker0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN mode DEFAULT group default 
    link/ether 02:42:99:eb:75:49 brd ff:ff:ff:ff:ff:ff

UPD: Thank you for your answers, guys! I figured it out and understood that my wifi adapter is rated for speeds up to 300Mbps, but I got only ~150, and I reinstalled drivers and got ~290-300 Mbps, and I guess it is an acceptable result.

127

1 + 10

wireless

internet

20.04

petep

5/27/24, 9:59 AM

your wifi adapter is 2.4 ghz

Никита Шейн

5/27/24, 10:00 AM

@petep Do you mean on the notebook?

24601

5/27/24, 11:49 AM

there are so many factors which affect WiFi capability - distance from router and structural obstructions such as stone walls for example. Your question and any answers will be very subjective.

waltinator

5/27/24, 2:27 PM

What's your WiFi MTU? `ip link` will tell you. For WiFi, MTU should be 1492, not 1500. Read `man ip ip-link`.

Никита Шейн

5/27/24, 3:45 PM

Hey @waltinator, Could you tell me how to install MTU to 1492, please?

vidarlo

5/27/24, 4:52 PM

@waltinator why on *earth* should MTU for WiFi be 1492 bytes? That's pure gibberish.

vidarlo

5/27/24, 4:52 PM

@НикитаШейн Please include the output of `iwconfig` to show signal conditions. 200Mb effective speed over 802.11ac is not half bad.

waltinator

5/27/24, 6:13 PM

You WiFi MTU is set by your DHCP provider, probably your router. A permanent fix should be done there. A fix lasting to the next reboot: `sudo ip link set dev wlo1 mtu 1492`.

vidarlo

5/27/24, 6:16 PM

@waltinator It is ***NOT*** a MTU problem. If it was, he should see the same issue on Wired Ethernet! He does not. Setting the MTU to 1492 ***will reduce the speed and may cause additional problems***. Come by in [chat](https://chat.stackexchange.com/rooms/201/ask-ubuntu-general-room) if you want me to explain the fallacy for you.

vidarlo

5/27/24, 6:32 PM

@waltinator In short - do *not* suggest that people should lower MTU on WiFi. It's not helpful except in very rare cases, and not in the general cases like this. It's not a solution to slow wifi; it is a solution when your upstream provider does not support a MTU of 1500B, such as when doing PPPoE. I see you've suggested it quite a few times, and that's plain bad advice, and may actually give users worse performance - as the router will happily send them 1500B frames, which their card will discard as being too big - leading to TCP retransmissions and packet loss!

Score:0

Ubuntu

vidarlo

5/28/24, 7:33 AM

200Mb is not half bad on 802.11ac. Theoretically you can reach 866Mb/s using the hardware you have - but that's not the achievable value, and includes a lot of overhead.

Under very good conditions I'd expect 350Mb/s from 802.11ac. That's with one or two clients, line of sight between access point and computer, and low noise on the selected frequency in your area.

If any of this is not true, such as a wall between you and the access point, 200Mb/s is a quite good speed.

You want faster WiFi? Replace the equipment with 802.11ax. 802.11ax can achieve 6-700Mb/s under good conditions. This entails replacing the WiFi-card in the laptop and the access point.

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