[Bluez-devel] 2. Re: Re: Re: Bluetooth SCO message sending (sco_send_frame)

[Bluez-devel] 2. Re: Re: Re: Bluetooth SCO message sending (sco_send_frame)

[Youngwoo Park]

In my case, there is some problem when I connect SCO over UART(h4).
When I sent data to h4 interface, h4 make frame and btsco sent that
frame to the SCO channel.
The frame size from h4 interface is varied periodically and somtimes
larger than MTU size so SCO channel drop several frames.

Of course I changed the MTU size using "hciconfig scomtu" command but it
is not effective at all.

Now, I tested the problem using samsung module based on CSR bluecore
chipset.
However, there is no problem if I use SCO over USB because the frame
size from USB is always same & smaller than MTU.

-- 
Youngwoo Park

M.S. Student
CORE(COmputer engineering REsearch) Lab
Dept. EECS, KAIST, Daejeon 305-701, Korea
Phone: +82-42-869-5425 Fax: +82-42-8695425
e-mail: ywpark@core.kaist.ac.kr

--




















-------------------------------------------------------
SF.Net email is Sponsored by the Better Software Conference & EXPO
September 19-22, 2005 * San Francisco, CA * Development Lifecycle Practices
Agile & Plan-Driven Development * Managing Projects & Teams * Testing & QA
Security * Process Improvement & Measurement * http://www.sqe.com/bsce5sf
_______________________________________________
Bluez-devel mailing list
Bluez-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/bluez-devel

Re: [Bluez-devel] 2. Re: Re: Re: Bluetooth SCO message sending (sco_send_frame)

[Marcel Holtmann]

Hi,

> In my case, there is some problem when I connect SCO over UART(h4).
> When I sent data to h4 interface, h4 make frame and btsco sent that
> frame to the SCO channel.
> The frame size from h4 interface is varied periodically and somtimes
> larger than MTU size so SCO channel drop several frames.
> 
> Of course I changed the MTU size using "hciconfig scomtu" command but it
> is not effective at all.

this command is useless.

> Now, I tested the problem using samsung module based on CSR bluecore
> chipset.
> However, there is no problem if I use SCO over USB because the frame
> size from USB is always same & smaller than MTU.

As I told you, the kernel will tell you the MTU size you have to use and
then you must segment and reassembly in your code.

Regards

Marcel




-------------------------------------------------------
SF.Net email is Sponsored by the Better Software Conference & EXPO
September 19-22, 2005 * San Francisco, CA * Development Lifecycle Practices
Agile & Plan-Driven Development * Managing Projects & Teams * Testing & QA
Security * Process Improvement & Measurement * http://www.sqe.com/bsce5sf
_______________________________________________
Bluez-devel mailing list
Bluez-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/bluez-devel