2022-02-23 13:55:34

by Arend van Spriel

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Subject: Re: [PATCH v2 1/3] cfg80211: Add NL80211_IFTYPE_MLO_LINK type for MLO links on MLD STA

On 2/23/2022 11:46 AM, Veerendranath Jakkam wrote:
> In contrast, NL80211_IFTYPE_MLO_LINK can't be used to represent AP MLO
> link since an MLD AP must support pre-11be and 11be clients
> simultaneously so each AP MLO link affiliated with AP MLD must also act
> as independent AP for pre-11be clients so each AP MLO link must be

Not just for pre-11be clients. 11be clients can opt-out right?

> represented by NL80211_IFTYPE_AP associated with a separate netdev.
>
> Two link AP MLD representation:
>
> AP MLD
> (netdev + wdev)
> / \
> / \
> wlan0 wlan1
> IFTYPE_AP IFTYPE_AP
> (netdev + wdev) (netdev + wdev)
> | |
> | |
> radio(2G) radio(5G)

So the AP MLD is a new IFTYPE? Earlier discussions were suggesting the
AP MLO links would be bridged, but then there would be only a netdev at
AP MLD level, right?

Regards,
Arend


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Subject: Re: [PATCH v2 1/3] cfg80211: Add NL80211_IFTYPE_MLO_LINK type for MLO links on MLD STA

On Wed, Feb 23, 2022 at 01:39:33PM +0100, Arend van Spriel wrote:
> On 2/23/2022 11:46 AM, Veerendranath Jakkam wrote:
> > In contrast, NL80211_IFTYPE_MLO_LINK can't be used to represent AP MLO
> > link since an MLD AP must support pre-11be and 11be clients
> > simultaneously so each AP MLO link affiliated with AP MLD must also act
> > as independent AP for pre-11be clients so each AP MLO link must be
>
> Not just for pre-11be clients. 11be clients can opt-out right?
>
> > represented by NL80211_IFTYPE_AP associated with a separate netdev.
> >
> > Two link AP MLD representation:
> >
> > AP MLD
> > (netdev + wdev)
> > / \
> > / \
> > wlan0 wlan1
> > IFTYPE_AP IFTYPE_AP
> > (netdev + wdev) (netdev + wdev)
> > | |
> > | |
> > radio(2G) radio(5G)
>
> So the AP MLD is a new IFTYPE? Earlier discussions were suggesting the AP
> MLO links would be bridged, but then there would be only a netdev at AP MLD
> level, right?

Yes, having a separate interface type for AP MLD sound like a clean approach.
Apart from the data path, AP MLD will be involved in control path as well.
AP MLD has its own wdev. Some of the control path APIs using AP MLD
interface are link affiliation/removal, remote MLD STA add, PTK key installation,
and intra-bss forwarding configuration. Also EAPoL frames are expected on
AP MLD interface.

Vasanth

2022-02-24 08:12:05

by Veerendranath Jakkam

[permalink] [raw]
Subject: Re: [PATCH v2 1/3] cfg80211: Add NL80211_IFTYPE_MLO_LINK type for MLO links on MLD STA



On 2/23/2022 6:09 PM, Arend van Spriel wrote:
> On 2/23/2022 11:46 AM, Veerendranath Jakkam wrote:
>> In contrast, NL80211_IFTYPE_MLO_LINK can't be used to represent AP MLO
>> link since an MLD AP must support pre-11be and 11be clients
>> simultaneously so each AP MLO link affiliated with AP MLD must also act
>> as independent AP for pre-11be clients so each AP MLO link must be
>
> Not just for pre-11be clients. 11be clients can opt-out right?
>

I think as of now spec is mandating to use multi-link capabilities in
11BE association. Anyways, current design is allows single link 11be
connections also in case if it is going to be allowed by spec in future.


--
- veeru

2022-02-26 20:14:44

by Arend van Spriel

[permalink] [raw]
Subject: Re: [PATCH v2 1/3] cfg80211: Add NL80211_IFTYPE_MLO_LINK type for MLO links on MLD STA

On February 24, 2022 8:59:07 AM Veerendranath Jakkam
<[email protected]> wrote:

> On 2/23/2022 6:09 PM, Arend van Spriel wrote:
>> On 2/23/2022 11:46 AM, Veerendranath Jakkam wrote:
>>> In contrast, NL80211_IFTYPE_MLO_LINK can't be used to represent AP MLO
>>> link since an MLD AP must support pre-11be and 11be clients
>>> simultaneously so each AP MLO link affiliated with AP MLD must also act
>>> as independent AP for pre-11be clients so each AP MLO link must be
>>
>> Not just for pre-11be clients. 11be clients can opt-out right?
>
> I think as of now spec is mandating to use multi-link capabilities in
> 11BE association. Anyways, current design is allows single link 11be
> connections also in case if it is going to be allowed by spec in future.

Reading clause 35.3.5 Multi-link (re)setup (D1.4) I would say it is
allowed. If the non-AP MLD doesn't include Basic multi-link element in the
(re)assoc request it is a single link request. In this case the non-AP MLD
is effectively a 11be STA. Maybe missing a clause describing the AP MLD
behavior in this scenario.

Regards,
Arend




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