[isp-wireless] YDI Issue

["Marty Dougherty" <mdougherty@...>]

Forrest:

Here is the only feedback that we have received from YDI to date…I do
have a few of the netgears- I can send you one. Send me your shipping
info and I’ll get you an early xmas gift!

Marty
_____________________________________________________________
From YDI:
Here is a summary of the our understanding of the situation:

Problem Statement:

Agere Hermes-I wireless PC Cards incorrectly associate with a Linksys AP
(Model: WAP11-2.8 with firmware v2.05 or higher) and a Netgear 'G'
router
regardless of the AP's Network Name setting. 


In summary, the following facts are known:

1. When both the intended AP and the Linksys AP (or Netgear device) are
within range of the EA, it's a 50:50 chance of which AP the unit will
join.

2. The exact same behavior has been observed using a Notebook PC (Win98
and
WinME), standard Hermes-I wireless card and the Agere Client Manager. 

3. The exact same behavior has been observed on the KN-50 (CPE device).

4. It been reported that the USB-Ant will behave the same way.

5. Engineering has been unable to find a single version of the H-1
code/firmware (HCF, HDF, NDIS, etc.) in which this problem does not
exist.
We believe it to be a fundamental issue with the PC Card firmware.

6. Upgrading any of the above configurations to a Hermes-II based PC
Card
will correct this problem.


Exchange / Capture:

The attached log file was generated via a program supplied by Agere
called
'snif'. This program has the ability to capture all frame types
transmitted
on a given channel (regardless of the source). It clearly high-lights
the
initial exchange between the Linksys-AP and the Client device. The
following
list outlines the various packets leading up to the improper
association:

 a. AP is Beacon'ing

 b. Client (at power-up) sends out a Probe Request
 c. AP sends back a Probe Response

 d. Client sends an Authentication Request
 e. AP reply's with an ACK

 f. AP sends an Authentication Request
 g. Client reply's with an ACK

 h. Client sends an Association Request
 i. AP reply's with an ACK

 j. AP sends an Association Request
 k. Client reply's with an ACK

 l. Both units start exchanging data


802.11 Protocol errors:

Based on the above exchange: two fundamental errors in the 802.11
standard
occurred.

1. The AP should never have responded in step 'c'. 

2. The PC Card should not have continued to step 'd' (i.e., the Network
Name
contained in the Probe Response was incorrect, the PC Card should have
rejected the frame and returned to step 'b').  The principle of
robustness
(famous RFC quote) applies here: "Be liberal in what you accept, and
conservative in what you send".


Agere's position is that the AP is to blame and that "but for" the AP
improperly responding, there would not be an issue.  This problem seems
to exist in all of the Agere cards sold to date, which probably numbers
in the millions!!!!!!  I am told that if you take any Agere card in a
PC, the same situation arises.

Interestingly, the new Hermes 2 cards do not exhibit this same behavior
so when we migrate to the next generation Agere chipset (which we will
do fairly soon) this problem should be resolved.

 
As far as going forward, our testing indicates that when we go to the
Hermes 2 chipset that this situation will be corrected.  We expect to
make this migration by the end of the year.  

I hope that this information is helpful for you and I look forward to
your information on how many occurrences that you have experiences and
any suggestions that you might have for moving forward.


----------------------------------------------------------------------



Subject: Re: YDI EtherAnt Issue
From: "Forrest W. Christian" <fwc@...>
Date: Thu, 14 Oct 2004 23:35:36 -0600
X-Message-Number: 40

Marty,

I have some suspicions as to what is going on, and I don't think it's a 
problem on the etherant end.  I really think the netgear (and possibly 
others) are responding to the client's "I'm looking for SSID X" message 
with their own mac address and the wrong SSID.

I really want to replicate this here on the bench, but haven't (thank 
the lord) been able to procure one of the netgears locally - probably 
why we haven't seen the problem yet.

Do you  (or someone sle) by chance have one of these you would be 
willing to drop in the mail and loan me for some testing purposes to 
verify this here, and so I can yell at YDI also if that is warranted?

-forrest










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