Bugzilla – Bug 542
short preamble support
Last modified: 2005-11-23 19:28:52
You need to log in before you can comment on or make changes to this bug.
It is not possible to associate to Intel PRO Wireless 5000 DAP AP in b mode with 2915 ABG card. Iwlist doesnt show BSSID of that AP at all. Association on band a with that AP is possible. Logs below. Repro: 1. Configure AP's band b (turn off band a) 2. Execute command: iwconfig eth1 essid ESSID
Created an attachment (id=233) [details] error_mode_b_0.21
Please try with a different firmware on the 5000. If it still fails, can you provide some packet sniff logs? Would like to rule out that it's a long/short preamble issue. Additional info: ala_ma_kota is the essid of the AP WEP is not enabled in AP
I've changed preamble type from short to long on AP and everything works fine now. So the problem is with short preamble. The firmware right now is 1.4-8.5 and the newest is 1.4.-8.5.1 so it probably wont change anything (no such fixes in release notes in 1.4-8.5.1 exist).
I've updated firmware to newest one and as I suspected it didnt change anything. Still association with short preamble in b mode is not possible.
Created an attachment (id=249) [details] Patch to attempt to enable short preamble support Please try the attached patch. If it works, great! If not, please load the driver at debug level 0x43fff and also enable debug on the ieee80211 module at level 0xf: . load debug=0x43fff echo 0xf > /proc/net/ieee80211/debug_level And provide the debug log that shows the probe response for the AP you are attempting to associate with, and the part of the debug log that shows the attempt to associate (including setting of the SSID through the association failure) Thanks, James
Created an attachment (id=250) [details] error_short_preamble.gz Applied the patch but it didnt help. Association is still impossible. There are logs as you requested in the attachment.
Would this then be the same issue as bug #377? If so, need to dupe them.
You may say that this bug is a result of #377. As can be seen problem lies in fact that driver support only long preamble so if AP will support only short one then we will not be able to associate with it. I think we should document it somehow - maybe in release notes or something - or solve the problem if this was not the intention. The same problem is with IBSS - if other card doesnt accept long preamble then we wont be able to associate with it. In b mode short preamble is optional but in g mode it is mandatory so I think we should investigate if we support short preamble in g mode and what type of preambles we support in b mode.
Marking as TO_BE_DOCUMENTED.
card can associate with short preamble APs in 1.0.6
Since no update for about 3 months, and I can assoicate AP with "iwpriv eth1 set_preamble 0", verify this bug. If anyone still find this problem, please reopen it.