hello all,
?? I want to know more about the TDLS implementation. According to IEEE
802.11z(http://standards.ieee.org/news/2011/80211z.html) which is
incorporated to IEEE 802.11-2012 document. It says that "A TDLS direct link is set up automatically, without need for user
intervention, while the connection with the AP is maintained". But in the mac80211 we need to configure the peer mac to make it work(using
wpa_supplicant), so as said by IEEE, without the need for user
intervention spec is not met right ?
Can someone throw some light into the TDLS feature in linux and the future road map.
Thanks for the help,
Dino Joseph Mycle
On Tue, Jun 19, 2012 at 6:33 AM, Dino Joseph Mycle <[email protected]> wrote:
> Hello Arik
>
> ? Thanks for the reply.
>
> For the TDLS, what you are saying is the IEEE standard does not talk how it
> can work without user intervention. For using security the user has to
> select the password (key) and it has to be entered, Also the system should
> ask the user whether or not the data has to be transferred through TDLS
> mode.
I'm not sure everything has to reach the user. I'm just saying not
every policy decision has to be made in kernel or wpa_supplicant.
As for the security key - I think it is derived from the key for the
AP network, so no separate key is needed. But you'll have to consult
the spec, my memory is a bit vague about this point.
>
> For the channel switch, if we do , the connection to the AP will get lost
> temporarily right, so if we are sending some data to the AP(say i am
> browsing and want to transfer some huge data to my peer laptop) it will be
> an issue right ?
Well we can get into power-save mode (PSM) vs. the AP, so it can't
send us more data while we are on the other channel. TDLS also has the
concept of PSM, to prevent the other peer from sending data.
Some cards should be able to support multi-channel operation soon, so
these kind of issues will be dealt with.
Arik
On Tue, Jun 12, 2012 at 8:10 PM, Dino Joseph Mycle <[email protected]> wrote:
> hello all,
>
> ?? I want to know more about the TDLS implementation. According to IEEE
> 802.11z(http://standards.ieee.org/news/2011/80211z.html) which is
> incorporated to IEEE 802.11-2012 document. It says that "A TDLS direct link is set up automatically, without need for user
> intervention, while the connection with the AP is maintained". But in the mac80211 we need to configure the peer mac to make it work(using
> wpa_supplicant), so as said by IEEE, without the need for user
> intervention spec is not met right ?
I don't think it necessarily contradicts the spec. The TDLS connection
can be made by a higher layer that gives commands to wpa_supplicant.
I think part of this is because HW limitations. Some devices can only
support a limited number of TDLS peers. So decisions have to be made
about who we want to connect to.
Channel switch is not always supported as well, so if we connect to a
TDLS peer, it might congest the network.
What I'm saying is - policy is not clear cut for TDLS.
Arik