Dear all,

Yet another question from me, sorry about that. I checked the Wiki but couldn't find anything.

My question:
Why is it that with stock TP-LINK firmware (on my wdr4900) when running WDS link, clients can still connect at 150 Mbit to the SSID of the WDS Station. With OpenWRT, on the other hand, clients only get single stream N - 65 Mbit when they connect to the WDS Station's SSID.

In sum:
Main Router (WDS Master) - Secondary Router (wdr4900 / WDS Station) - SSID of wdr4900 - Client (Stock: 150 Mbit/OpenWRT: 65 Mbit connection)

Anyone have an explanation? I can see that the WDS Master and Station are connected at a speed of 270-300 Mbit, thus leaving very little room for the secondary SSID. Honestly, I would rather have the WDS link function at 150 Mbit and the SSID function at 150 Mbit.

My wan downstream is 60 Mbit so 150 Mbit WDS link is sufficient anyway.

Thank you for helping / reading
Emile

(Last edited by Boompje123 on 30 Jun 2013, 08:38)

have you checked the "noscan" option?

http://wiki.openwrt.org/doc/uci/wireless#common.options

Yep its set at 1

config wifi-device 'radio0'
    option type 'mac80211'
    option channel '36'
    option hwmode '11na'
    option path 'pci0000:00/0000:00:00.0/0000:01:00.0'
    option htmode 'HT20'
    list ht_capab 'LDPC'
    list ht_capab 'SHORT-GI-20'
    list ht_capab 'SHORT-GI-40'
    list ht_capab 'TX-STBC'
    list ht_capab 'RX-STBC1'
    list ht_capab 'DSSS_CCK-40'
    option noscan '1'

config wifi-device 'radio1'
    option type 'mac80211'
    option hwmode '11ng'
    option path 'pci0001:02/0001:02:00.0/0001:03:00.0'
    list ht_capab 'LDPC'
    list ht_capab 'SHORT-GI-20'
    list ht_capab 'SHORT-GI-40'
    list ht_capab 'TX-STBC'
    list ht_capab 'RX-STBC1'
    list ht_capab 'DSSS_CCK-40'
    option country 'NL'
    option channel '13'
    option htmode 'HT40-'
    option txpower '20'
    option noscan '1'

config wifi-iface
    option ssid 'MainSSIDtoBridge'
    option encryption 'psk2'
    option device 'radio1'
    option mode 'sta'
    option bssid 'F8:D1:11:BE:2C:6A'
    option key 'XXX'
    option wds '1'
    option network 'lan wan'

config wifi-iface
    option device 'radio1'
    option mode 'ap'
    option encryption 'psk2+ccmp'
    option key 'XXX'
    option ssid 'SecondarySSID'
    option network 'lan wan'

(Last edited by Boompje123 on 30 Jun 2013, 12:13)

I don't know why you can't connect at full speed, maybe I'd try to pick a different channel like 12 (13 is at the edge of the spectrum). But 150 mbit wifi will handle 60mbit connection only in ideal conditions, if you're in the same room with router and far away from civilization and interference.

well, i tried an simpler setup on my wr703n, with AA 12.09, a client, and an ap, on the same and only radio.

with only the ap enabled, it supports HT40 and rate is 150 Mbps, when enabling also client, it stops broadcasting HT Capabilities, and the clients connects at 65 Mbps maximum.

also Inssider shows channel 1 and max rate 65 Mbps, while before it showed 1+5 and 150 Mbps.

seems to me like a bug when there are multiple interface on same radio?

here is a wireshark cap file that shows difference between the 2 Beacons:

https://www.dropbox.com/s/g0eglkdoi3j9q4o/ht_prob.cap

look under Tag: HT Information Subset

EDIT:

https://dev.openwrt.org/ticket/12720

-.-

(Last edited by nebbia88 on 30 Jun 2013, 16:39)

Thanks for the info guys. So it looks like its a bug.. kinda annoying.

I'll try switching channels/HT tomorrow. Just did a quick test on channel 12 tho, that didn't change anything

Again, will try some more tomorrow.

Thanks!

Also: thanks for testing nebbia. That's super kind

Posted culprit process and temporary solution for this bug on the tracker https://dev.openwrt.org/ticket/12720#comment:22

Here is a copy and paste for the lazy: