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Re: [bluetooth-dev] Echo request



Mattias,

Thank you for your answer.

Will the PSM problem be fixed before UPF-3 ?

There is a problem with the ping implementation.
It is not necessary to have a L2CAP channel opened before isuing an echo
request. But today, from a layer on top of l2cap, it is not possible to
open a baseband connection without issuing a l2ca_connect_req.
Do you think this is an important limitation to the stack ?

Adding a function like "l2ca_ping_req" in the l2cap.c file doesn't look
nice as it is not defined as a "service to upper layer" in the standard.

What do you suggest ?

Regards,

David.

Mattias Ågren wrote:
> 
> >
> > After some time I found out that
> >     - The echo request is already implemented in the stack.
> >     - PSM 0x1231 is already taken into account in L2CAP when
> > UNPLUG_TEST
> > is defined and the test layer is registered with PSM = MAX_PSM-1.
> >
> > I would have appreciated a short email from someone at Axis telling me
> > that.
> > It would have saved me some time.
> 
> Hi David,
> 
> Sorry for the misunderstanding.... you asked if PING was implemented not echo request. Since there is no PING yet there is no indications up to higher layers when an echo request is received. Feel free to do it yourself and we'll be happy to add it in the stack.
> 
> Regarding the MAX_PSM and the unplug test stuff that was just a temporary fix and will be replaced by a 'real' PSM for the test layer. Each upper layers function pointer struct will be dynamically allocated when registered thus we could use any MAX_PSM we'd like without allocating a lot of unused memory (currently there are MAX_PSM struct allocated statically...thus the temp fix for PSM=0x1231:) ).
> 
> Brgds
> Mattias
> 
> > -----Original Message-----
> > From: David LIBAULT [mailto:dli@xxxxxxx.fr]
> > Sent: Wednesday, August 02, 2000 4:01 PM
> > To: bluetooth-dev@xxxxxxx.com
> > Subject: [bluetooth-dev] Echo request
> >
> >
> > Hi,
> >
> > Does anyone know how an echo request is indicated to the
> > upper layers ?
> >
> > Regards.
> >