Re: [STDS-802-11-TGM] Minutes posted for Oct 12th Telecon
--- This message came from the IEEE 802.11 Task Group M Technical Reflector ---
Mark,
I was being quite specific, intentionally. We can argue about my approach, but I don't think I mixing anything up.
From 802.1X, "EAPOL PDUs" are exchanged between PAEs. And, further, 802.1X specifically talks about these being exchanged by passing them as MSDUs to the MAC Service. So, EAPOL PDUs _are_ 802.11 MSDUs (not "carried by" them). This all makes sense, as 802.1X PAEs are MAC Service users.
I have no opinion whether EAPOL PDUs can be fragmented by 802.11 (or any other MAC Service). I don't see why not - they are just another MSDU at the level where fragmentation is done. Thus, again, I claim that EAPOL PDUs are MSDUs like any other.
What I am trying to convey with this new definition/concept is what an "EAPOL-Key frame" (and its various other spellings) means. We call this a "frame" and the text discusses these being "exchanged" with peer entities. That means they are PDUs (to some entity). From 802.1X, its PDUs are EAPOL PDUs. But, also from 802.1X, these PDUs are delivered to the MAC Service (as MSDUs) and are then carried 'on the wire' or 'on the air' (those are 802.1X's words) using 'EAPOL frames' at the MAC Service layer. That is, the MAC Service takes the EAPOL PDU and applies MAC-specific procedure and protocol to result in the actual frame exchange that carries the EAPOL PDUs to the peer PAE. In our case, we do that with data MPDUs. I believe there is a simple mapping, then, that 802.11 has data MPDUs that carry lots of MSDUs. Sometimes those MSDUs happen to be EAPOL PDUs. And, in that case, the data MPDUs can be referred to as EAPOL frames, or, EAPOL-Key frames as we have chosen.
The attempt is to explain what discussion like that in 4.5 and 4.10, and pictures like Figure 12-2 (802.11-2012) are showing. I don't think it helps us to talk about these being MSDUs, as that makes the terms "frame" or "exchange" in this context very confusing with respect to the usage of these terms in the rest of the Standard.
Since you brought up fragmentation, while I doubt fragmentation of EAPOL PDUs ever happens, we could perhaps cover this case more correctly by saying that an EAPOL-Key frame is a data MPDU that carries "some or all" of an EAPOL PDU. Thus, if an EAPOL PDU does have to be carried via more than one data MPDU, each with a fragment, then each of those data MPDUs is an EAPOL-Key frame. I think this still works, and keeps everything consistent. But, I also think it is probably overkill.
Mark
-----Original Message-----
From: Mark Rison [mailto:m.rison@xxxxxxxxxxx]
Sent: Sunday, October 28, 2012 12:07 AM
To: Hamilton, Mark; STDS-802-11-TGM@xxxxxxxxxxxxxxxxx
Subject: RE: [STDS-802-11-TGM] Minutes posted for Oct 12th Telecon
I won't pretend to know about 802.1 or 802.1X, but I would like to make sure we're not going to get our MSDUs and MPDUs mixed up again. So:
> I looked at 802.1-2010 for an updated reference place for this
> concept. Looking there, I note that Clause 11 is where this 'frame'
> is defined in detail. And, that clause is quite consistent in using
> the term 'EAPOL PDU' for the information units exchanged between PAEs. [...] EAPOL PDUs are MSDUs to the MAC Service.
So far so good...
> Add a definition in subclause 3.2, "EAPOL-Key frame: An 802.11 data
> MPDU which carries an 802.1X EAPOL PDU."
Unless 802.1X EAPOL PDUs can't be fragmented when carried over 802.11 (and I would be somewhat surprised by such a constraint) then surely it should be "An 802.11 MSDU which carries"?
> Add a sentence to the end of the second paragraph of subclause 4.2.5:
> "Within 802.11, EAPOL PDUs are carried as MSDUs within data MDPUs, as
> described in 802.1X-2010, clause 11; data MPDUs used for this purpose are known within this Standard as EAPOL-Key frames."
Similarly, I think "MSDUs used for this purpose" would be better.
The reference to data MPDUs risks confusing things, so I would delete "within data MPDUs" too.
Oh, and does 802.1X-2010 really describe carrying EAPOL PDUs as MSDUs?
Shouldn't the "as described" refer to the EAPOL PSDUs, not the (802.11) MSDUs?
What about the "EAPOL-Start frame"s, "EAPOL frame"s and "EAPOL-Key request frame"s of Jouni's suggestion, though?
So I'm wondering (again, from my limited understanding of 802.1) whether it shouldn't be something like:
<<
EAPOL frame: An 802.11 MSDU which carries an 802.1X EAPOL PDU.
EAPOL-Key frame: An EAPOL frame of type EAPOL-Key.
EAPOL-Key request frame: An EAPOL-Key frame with the Request bit set.
EAPOL-Start frame: An EAPOL frame of type EAPOL-Start.
[Adjust the "of type" and "Request bit" bits to use the correct 802.1X terminology]
Within 802.11, EAPOL PDUs, as described in 802.1X-2010 clause 11, are carried as MSDUs; MSDUs used for this purpose are known within this Standard as EAPOL frames (and sometimes more specifically as EAPOL-Key frames, EAPOL-Key request frames or EAPOL-Start frames).
>>
> Change the start of the sentence in 4.10.2, "IEEE 802.1X
> authentication frames are transmitted in IEEE
> 802.11 data frames ..." to "IEEE 802.1X EAPOL PDUs are transmitted in
> IEEE 802.11 data MPDUs known as EAPOL-Key frames ..."
"in IEEE 802.11 MSDUs". Also maybe "as EAPOL frames", per the above.
> In the table in subclause 6.3.22.1.2, change "EAPOL-Key frame" to "EAPOL PDU"
Mark
--
Mark RISON, Systems Architect, Wi-Fi English/Esperanto/Français
Samsung Cambridge Solution Centre Tel: +44 1223 434600
Innovation Park, Cambridge CB4 0ZT Fax: +44 1223 TBCTBC
ROYAUME UNI WWW: http://www.samsung.com/uk
> -----Original Message-----
> From: ***** IEEE stds-802-11-tgm List *****
> [mailto:STDS-802-11-TGM@xxxxxxxx] On Behalf Of Hamilton, Mark
> Sent: 28 October 2012 13:31
> To: STDS-802-11-TGM@xxxxxxxxxxxxxxxxx
> Subject: Re: [STDS-802-11-TGM] Minutes posted for Oct 12th Telecon
>
> --- This message came from the IEEE 802.11 Task Group M Technical
> Reflector ---
>
> On Friday's teleconference, I took an action item to propose some text
> setting a convention for the use of the term "EAPOL frame".
>
>
>
> In investigating the wording for this, I looked at 802.1-2010 for an
> updated reference place for this concept. Looking there, I note that
> Clause 11 is where this 'frame' is defined in detail. And, that
> clause is quite consistent in using the term 'EAPOL PDU' for the
> information units exchanged between PAEs. While other parts of 802.1X
> are less consistent, this clause seems to layout the idea that EAPOL PDUs are exchanged via the MAC transmission and reception of EAPOL frames. EAPOL PDUs are MSDUs to the MAC Service.
>
>
>
> Thus, I propose:
>
>
>
> Add a definition in subclause 3.2, "EAPOL-Key frame: An 802.11 data
> MPDU which carries an 802.1X EAPOL PDU."
>
>
>
> Add a sentence to the end of the second paragraph of subclause 4.2.5:
> "Within 802.11, EAPOL PDUs are carried as MSDUs within data MDPUs, as
> described in 802.1X-2010, clause 11; data MPDUs used for this purpose are known within this Standard as EAPOL-Key frames."
>
>
>
> Change the start of the sentence in 4.10.2, "IEEE 802.1X
> authentication frames are transmitted in IEEE
> 802.11 data frames ..." to "IEEE 802.1X EAPOL PDUs are transmitted in
> IEEE 802.11 data MPDUs known as EAPOL-Key frames ..."
>
>
>
> In the table in subclause 6.3.22.1.2, change "EAPOL-Key frame" to "EAPOL PDU"
>
>
>
> I also suggest we update the references to 802.1X to be to the
> 802.1X-2010 revision. On a quick scan, I don't see that there is any
> terminology becomes out-of-date. There are a couple specific clause
> references that need updating: in 11.6.2, clause references to 7.1
> need to be 11.3 for the first occurrence and 11 for the second. I believe we can just change 802.1X-2004 to 802.1X-2011 in all other occurrences. But, I'm not an expert on this, and experts should review for any subtle changes.
> I could perhaps submit this as a comment on D1.0, if we're more comfortable with that.
>
>
>
> Lastly, I also found many uses of the phrase “802.1X frame(s)” which I
> think slipped past Jouni’s list (by not having ‘EAPOL’ in them), but should also be modified in the same way.
>
>
>
> I welcome comments on any of the above.
>
>
>
> Mark
>
>
>
> -----Original Message-----
> From: ***** IEEE stds-802-11-tgm List *****
> [mailto:STDS-802-11-TGM@xxxxxxxx] On Behalf Of Jouni Malinen
> Sent: Friday, October 26, 2012 7:38 AM
> To: STDS-802-11-TGM@xxxxxxxxxxxxxxxxx
> Subject: Re: [STDS-802-11-TGM] Minutes posted for Oct 12th Telecon
>
>
>
> --- This message came from the IEEE 802.11 Task Group M Technical
> Reflector ---
>
>
>
> On Fri, Oct 12, 2012 at 8:59 PM, Jon Rosdahl <jrosdahl@xxxxxxxx <mailto:jrosdahl@xxxxxxxx> > wrote:
>
> > ACTION ITEM: Jouni to take some time to research and provide a
>
> > proposal for the usage of the “EAPOL_Key frame”’ name issue.
>
>
>
> Existing references to Data frames that use EAPOL ethertype:
>
>
>
> IEEE Std 802.11-2012:
>
>
>
> EAPOL-Key frame
>
> EAPOL-Key Frame
>
> IEEE 802.1X EAPOL-Key frame
>
> 802.1X EAPOL-Key frame
>
> EAPOL-Key
>
> EAPOL-Key message
>
> EAPOL-Key Message
>
> EAPOL-Key 4-Way Handshake Message
>
> EAPOL-Key request frame
>
> EAPOL-Key Request frame
>
> EAPOL-Key request message
>
> EAPOL request message
>
> IEEE 802.1X EAPOL frame
>
> EAPOL message
>
> EAPOL-Start message
>
> EAPOL-Start packet
>
> IEEE 802.1X EAPOL-Start message
>
> EAP authentication frame
>
> EAP-Request/Identity message
>
>
>
>
>
> IEEE Std 802.1X-2010
>
>
>
> EAPOL PDU
>
> EAPOL frame
>
> EAPOL-Key
>
> EAPOL-Key frame
>
> EAPOL-Start
>
> EAPOL-Start frame
>
> EAPOL-Start PDU
>
> EAPOL-Start packet
>
> EAPOL-EAP frame
>
> EAP message
>
>
>
>
>
> "EAPOL* frame" and "EAPOL*" are the most commonly used forms.
>
>
>
>
>
> Proposal for P802.11-REVmc:
>
>
>
> EAPOL-Key Frame --> EAPOL-Key frame
>
> IEEE 802.1X EAPOL-Key frame --> EAPOL-Key frame 802.1X EAPOL-Key frame
> --> EAPOL-Key frame EAPOL-Key message --> EAPOL-Key frame EAPOL-Key
> Message --> EAPOL-Key frame EAPOL-Key Request frame --> EAPOL- Key
> request frame EAPOL-Key request message --> EAPOL-Key request frame
> EAPOL request message --> EAPOL-Key request frame IEEE 802.1X EAPOL
> frame --> EAPOL frame EAPOL message --> EAPOL frame EAPOL- Start
> message --> EAPOL-Start frame EAPOL-Start packet --> EAPOL-Start frame
> IEEE 802.1X EAPOL-Start message --> EAPOL-Start frame EAP
> authentication frame --> EAP message
>
>
>
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