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From:   Luiz Augusto von Dentz <luiz.dentz@gmail.com>
Date:   Fri, 30 Sep 2022 13:12:14 -0700
Message-ID: <CABBYNZL94jw-pGuqv-zUaxLk_OFwEBxLcWm2Oyg3Q3FQPK_XRA@mail.gmail.com>
Subject: Re: bluetoothctl: Connecting to a GATT service using BR/EDR
To:     Christian Eggers <ceggers@arri.de>
Cc:     linux-bluetooth@vger.kernel.org
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Hi Christian,

On Fri, Sep 30, 2022 at 12:56 PM Christian Eggers <ceggers@arri.de> wrote:
>
> Hi Luiz,
>
> On Friday, 30 September 2022, 21:33:28 CEST, Luiz Augusto von Dentz wrote=
:
> > Hi Christian,
> >
> > Connecting over BR/EDR as a central is currently not supported, it
> > will probably require some changes in order to enable it although the
> > likes of bt_att/bt_gatt_client shall have proper support for it.
>
> currently it takes several seconds to read 70 KiB over a FIFO like GATT
> characteristic. Is this normal? In which configuration I can get the
> maximum throughput? Is it worth to tune the BLE parameters or should I
> use BR/EDR with a "classic" profile instead?

If you want to maximize throughput you will probably need to change
the connection parameters and perhaps use L2CAP directly since ATT is
not very efficient and you either have to resort to unreliable write
without response+notify or wait for write responses. If you want to do
file based transfer Id suggest you looking into implementing Object
Transfer Service which uses L2CAP CoC to maximize data transfers,
alternatively you can use OBEX if you prefer using BR/EDR, that said
it would be great to have support for OTS since that is used by the
likes of Media Control Service which is part of LE Audio stack.

>
> regards,
> Christian
>
>
>
> _______________________________________________________
> Christian
> Eggers
> Software Engineer
> ARRI
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--=20
Luiz Augusto von Dentz