bluetooth 2.0 is extremely slow

Mike Cronenworth mike at cchtml.com
Sat Apr 5 05:50:09 UTC 2008


-------- Original Message  --------
Subject: Re:bluetooth 2.0 is extremely slow
From: Bastien Nocera <bnocera at redhat.com>
To: mike at cchtml.com, Development discussions related to Fedora 
<fedora-devel-list at redhat.com>
Date: 04/01/2008 11:28 AM
> On Tue, 2008-04-01 at 11:11 -0500, Mike Cronenworth wrote:
>   
>> Hi all,
>>
>> I've lived with slow transfer speeds long enough. Ever since I purchased
>> an ASUS Bluetooth 2.0+EDR USB adapter it has always taken *minutes*
>> instead of *seconds* to transfer files from my cell phone to my computer
>> and vice versa.
>>
>> Fedora 8, latest updates.
>> Nokia N95-1, latest firmware.
>>
>> Both are Bluetooth 2.0+EDR devices.
>>
>> It took *40 seconds* to transfer a 1 megabyte picture. I timed this with
>> 'watch -n 1 date' for grins, so I can't give you nanosecond numbers, but
>> even a rough estimate shows that transfer speeds are *abysmal* and need
>> to be addressed. Ideally it should be taking less than 10 seconds to
>> transfer the same image file on a true 2.0+EDR setup. I have two
>> different computers with two of the same Asus adapter. Same speeds.
>>     
>
> That certainly doesn't rule out a bug in the dongle's firmware for
> example.
>   

I punched myself into loading Windows XP (latest updates, latest 
drivers) and the same file (or any 1 meg file) transfers in *10 
seconds*. A factor of four on speed improvement. There's nothing wrong 
with the firmware.

>   
>> I saw someone fixed this by forcing larger MTUs.
>> http://lists.freebsd.org/pipermail/...ary/000847.html
>> <http://lists.freebsd.org/pipermail/freebsd-bluetooth/2007-January/000847.html>
>>
>> Before modifying the OpenOBEX sources, I posted a message on their
>> board, but I haven't heard anything yet. Does anyone have any experience
>> with this?
>>     
>
> OpenObex upstream is pretty much dead(-ish). Let's call it maintenance
> mode.
>
>   
>> I have tried the fedora-list without an answer. Also, the OpenOBEX 
>> developers are silent on this. Is this because no one has a 2.0 adapter 
>> and 2.0 device?
>>     
>
> Probably not, one of the upstream for OpenObex is Marcel Holtmann, and
> he certainly has more Bluetooth 2.0 devices than you or I.
>
> Test the patch, tell us if it works, and mail the bluez-users list about
> it. There's also ACL and SCO MTUs to take in consideration, and I would
> guess the bug is more likely to be there (in the kernel, in the firmware
> of your dongle, or the firmware of your phone) than solely in OpenObex.
>   
I will try messing with OpenOBEX and report back. If no one else 
ventures into this... it might be a while. I don't have a lot of time to 
give to this.
> Cheers
>
>   

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