3

Is there a way in OpenWrt to read the current value of the RTS threshold for a specific interface without installing iwconfig?

What I'm looking for is the value of RTS thr that can be found in the output of iwconfig device:

wlp2s0    IEEE 802.11bgn  ESSID:"my_essid"  
          Mode:Managed  Frequency:2.412 GHz  Access Point: 00:DE:AD:BE:EF:00   
          Bit Rate=54 Mb/s   Tx-Power=16 dBm   
          Retry  long limit:7   RTS thr:off   Fragment thr:off

Since iwconfig is deprecated, I'm looking for a way to obtain this value with iw or by reading some system files.

What seems strange is that with iw I can set the RTS threshold by using

 iw phy phy0 set rts 80

but I can't read it. After that command the output of iwconfig is

wlp2s0    IEEE 802.11bgn  ESSID:"my_essid"  
          Mode:Managed  Frequency:2.412 GHz  Access Point: 00:DE:AD:BE:EF:00    
          Bit Rate=54 Mb/s   Tx-Power=16 dBm   
          Retry  long limit:7   RTS thr=80 B   Fragment thr:off
          Encryption key:off
          Power Management:off
          Link Quality=70/70  Signal level=-19 dBm  
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:26  Invalid misc:1916   Missed beacon:0

So the actual question is: where does iwconfig read the value of RTS thr?

2

While iwconfig prints the RTS threshold anyway, iw prints it only when the RTS mechanism is enabled.

In order to read the value the command is

iw phy phy0 info | grep RTS

which outputs no lines if RTS is off or something like

RTS threshold: <number>

if it's enabled.

0

This took a while to route out but I think what you're asking is as follows. In the output of iwconfig:

$ sudo iwconfig
wlp3s0    IEEE 802.11bgn  ESSID:"none_of_your_business_1"  
          Mode:Managed  Frequency:2.437 GHz  Access Point: 00:22:3F:03:5C:67   
          Bit Rate=54 Mb/s   Tx-Power=14 dBm   
          Retry  long limit:7   RTS thr:off   Fragment thr:off
          Encryption key:off
          Power Management:off
          Link Quality=62/70  Signal level=-48 dBm  
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:0  Invalid misc:225   Missed beacon:0

Specifically this line:

          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0

These values are accessible under the /sys filesystem if you know where to look. My WiFi device is located here under the /sys:

$ sudo more /sys/kernel/debug/iwlwifi/0000:03:00.0/iwldvm/debug/ucode_rx_stats

The corresponding lines from that file?

Statistics_Rx - OFDM:               current  cumulative       delta         max
  unresponded_rts:                        0           0           0           0
  • The value of unresponded_rts is related to the topic but that's not what I'm looking for; that file is also driver-dependent and I'm not using an Intel card. I edited the question to make it (hopefully) clearer – David Costa Apr 7 '14 at 14:27

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.