2003-08-20 16:20:35

by Aarti Kumar

[permalink] [raw]
Subject: [Bluez-devel] avdtp over l2cap


I am trying place avdtp layer over l2cap layer with
the existing bluez stack.
I have just come up with basic socket implementation
for avdtp.
I am not sure whether existing l2cap layer supports
avdp, and whether i need to make any changes to it. As
far as i could understand all the layers above l2cap
have there psm set, and l2cap layer is not aware of
these values.
I understand the BTPROTO has been defined for
l2cap,rfcomm,bnep, sco from 0-4 and while registering
it checks for the value less than 5, so if need to
register avdtp as BTPROTO_AVDTP 5 , i have to modify
the condition.
What else do i need to do , so that i can send and
receive messages through avdtp sockets ?
Also I am not sure about the Socket Option level
(SOL_AVDTP) value for AVDTP ?
I quite new to this kernel programming stuff , so
pardon me if my question is too naive .

Thanks,
Aarti.


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2003-08-20 20:36:36

by Marcel Holtmann

[permalink] [raw]
Subject: Re: [Bluez-devel] avdtp over l2cap

Hi Aarti,

> So you suggest that i can have the implementation of
> audio video tranport protocol in the userspace itself.
> This means that i dont need to have socket ineterface
> for audio video distribution protocol , instead i will
> have the program which will be using l2cap sockets and
> forming a connection between two devices.
>
> What i think is audio video tranfer protocol should be
> implemented as module (like bnep, rfcomm and sco) and
> regisered in bluetooth stack. The profile development
> or the application using this will be in userspace
> (like pand and sdp).

take another deep look into the AVDTP spec. and you will see that it
adopts the two major protocols RTP and RTCP. The TCP/IP implementation
of both protocols fits perfect into userspace and so should AVDTP do as
well. The AVDTP has not to interact with any other kernel subsystems and
so there is no need to put it into the kernel.

Regards

Marcel




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2003-08-20 19:50:27

by Aarti Kumar

[permalink] [raw]
Subject: Re: [Bluez-devel] avdtp over l2cap

Hi,
So you suggest that i can have the implementation of
audio video tranport protocol in the userspace itself.
This means that i dont need to have socket ineterface
for audio video distribution protocol , instead i will
have the program which will be using l2cap sockets and
forming a connection between two devices.

What i think is audio video tranfer protocol should be
implemented as module (like bnep, rfcomm and sco) and
regisered in bluetooth stack. The profile development
or the application using this will be in userspace
(like pand and sdp).

Thats it for now.
Thanks,
Aarti.
--- Marcel Holtmann <[email protected]>
wrote:
> Hi Aarti,
>
> > I am trying place avdtp layer over l2cap layer
> with
> > the existing bluez stack.
> > I have just come up with basic socket
> implementation
> > for avdtp.
> > I am not sure whether existing l2cap layer
> supports
> > avdp, and whether i need to make any changes to
> it. As
> > far as i could understand all the layers above
> l2cap
> > have there psm set, and l2cap layer is not aware
> of
> > these values.
> > I understand the BTPROTO has been defined for
> > l2cap,rfcomm,bnep, sco from 0-4 and while
> registering
> > it checks for the value less than 5, so if need to
> > register avdtp as BTPROTO_AVDTP 5 , i have to
> modify
> > the condition.
> > What else do i need to do , so that i can send and
> > receive messages through avdtp sockets ?
> > Also I am not sure about the Socket Option level
> > (SOL_AVDTP) value for AVDTP ?
> > I quite new to this kernel programming stuff , so
> > pardon me if my question is too naive .
>
> some time ago I also looked at the AVDTP and you
> don't need to write a
> kernel module for it. It can be done in userspace
> like SDP, OBEX, HCRP
> etc.
>
> Regards
>
> Marcel
>
>


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2003-08-20 16:44:10

by Marcel Holtmann

[permalink] [raw]
Subject: Re: [Bluez-devel] avdtp over l2cap

Hi Aarti,

> I am trying place avdtp layer over l2cap layer with
> the existing bluez stack.
> I have just come up with basic socket implementation
> for avdtp.
> I am not sure whether existing l2cap layer supports
> avdp, and whether i need to make any changes to it. As
> far as i could understand all the layers above l2cap
> have there psm set, and l2cap layer is not aware of
> these values.
> I understand the BTPROTO has been defined for
> l2cap,rfcomm,bnep, sco from 0-4 and while registering
> it checks for the value less than 5, so if need to
> register avdtp as BTPROTO_AVDTP 5 , i have to modify
> the condition.
> What else do i need to do , so that i can send and
> receive messages through avdtp sockets ?
> Also I am not sure about the Socket Option level
> (SOL_AVDTP) value for AVDTP ?
> I quite new to this kernel programming stuff , so
> pardon me if my question is too naive .

some time ago I also looked at the AVDTP and you don't need to write a
kernel module for it. It can be done in userspace like SDP, OBEX, HCRP
etc.

Regards

Marcel




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careers in IT to Engineering to Tech Sales, Dice has tech jobs from the
best hiring companies. http://www.dice.com/index.epl?rel_code=104
_______________________________________________
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