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Re: [bluetooth-dev] Line collision between SDP and RF_COMM



Hi Ran Zhou,

Ran Zhou wrote:

> On Wed, 30 Jan 2002 11:15:40 +0100 Matthias Fuchs 
> <matthias.fuchs@xxxxxxx.com> wrote:
> 
> 
>>Hi Ran Thou,
>>
>>you are right, I noticed the second problem some timeago.
>>
>>I have an application where two rfcomm data channels are needed:
>>
>>Device A connects to device B through rfcomm for LAN access. Further Device A needs
>>a rfcomm connection to device B for a special custom application that relies on a transparent
>>serial connection (no TCP/IP/PPP). It is not possible to setup these two connections
>>at the same time. 
>>
> Hi, Matthias:
>   Do you mean, device A can setup two rf_comm connections with B using 
>   different 'line'?

You can do that. OpenBT does not complain about that. But the second RFCOMM channel does not work !

> 
> I am not sure what happens if SDP is also connected at the same time.

Same with me !

Did anybody else check out if two RFCOMM channels between the same two devices can be setup at the
same time ?

Matthias


> 
>>Should we allow such scenarios ?
>>
>>Matthias
>>
>>Ran Zhou wrote:
>>
>>
>>>Hi,
>>>OpenBT(I am currently using OpenBT-20010816) uses 'line' for sdp 
>>>connection object and rf_comm connection object, this may cause 
>>>trouble for application.For example:
>>>1. If device A opened connection to device B, A would get line0 for
>>>   the connection. Then if B opened a rf_comm connection to A, the 
>>>   stack in A would assign line0 to the rf_comm connection unawaring
>>>   that the line had already assigned to sdp connection. The application
>>>   in A would have no way to use ioctl command 'BTISLOWERCONNECTED' to 
>>>   detect the rf_comm connection and can't open /dev/ttyBT0.
>>>2. There is possibility (I guess OpenBT doesn't want this happens)
>>>   that the A can have more than one 'line'  connecting to B(eg. one 
>>>   for rf_comm, one for sdp). This will cause problem too if you use
>>>   'BTREADREMOTEBDADDR'.
>>>These are just my experience, someone may correct me if I am wrong.
>>>
>>>Regards
>>>
>>>Ran 
>>>
>>>----------------------
>>>Ran Zhou
>>>Centre for Communications Research
>>>University of Bristol
>>>c/o: PACT
>>>University Gate                            Tel:  +44 117 915 1278
>>>Park Row                                   Fax:  +44 117 954 5206
>>>Bristol BS1 5UB                          
>>>United Kingdom                             Email: Ran.Zhou@xxxxxxx.uk
>>>
>>>-
>>>To unsubscribe from this list: send the line "unsubscribe bluetooth-dev" in
>>>the body of a message to majordomo@xxxxxxx.com
>>>
>>>
>>>
>>>
>>>
>>
>>-- 
>>-------------------------------------------------------------------------
>>
>>                             _/_/_/_/   Matthias Fuchs
>>                            _/_/_/_/   Dipl.-Ing.
>>                           _/_/_/_/   matthias.fuchs@xxxxxxx.com
>>
>>       _/_/_/   _/_/_/_/_/_/_/      esd electronic system design gmbh
>>     _/   _/  _/             _/    Vahrenwalder Str. 207
>>    _/   _/    _/_/_/   _/   _/   D-30165 Hannover
>>    _/             _/  _/   _/   Phone: +49-511-37298-0
>>     _/_/_/_/_/_/_/   _/_/_/    Fax:   +49-511-37298-68
>>
>>-------------------------------------------------------------------------
>>
>>-
>>To unsubscribe from this list: send the line "unsubscribe bluetooth-dev" in
>>the body of a message to majordomo@xxxxxxx.com
>>
> 
> ----------------------
> Ran Zhou
> Centre for Communications Research
> University of Bristol
> c/o: PACT
> University Gate                            Tel:  +44 117 915 1278
> Park Row                                   Fax:  +44 117 954 5206
> Bristol BS1 5UB                          
> United Kingdom                             Email: Ran.Zhou@xxxxxxx.uk
> 
> 
> 
> 


-- 
-------------------------------------------------------------------------

                             _/_/_/_/   Matthias Fuchs
                            _/_/_/_/   Dipl.-Ing.
                           _/_/_/_/   matthias.fuchs@xxxxxxx.com

       _/_/_/   _/_/_/_/_/_/_/      esd electronic system design gmbh
     _/   _/  _/             _/    Vahrenwalder Str. 207
    _/   _/    _/_/_/   _/   _/   D-30165 Hannover
    _/             _/  _/   _/   Phone: +49-511-37298-0
     _/_/_/_/_/_/_/   _/_/_/    Fax:   +49-511-37298-68

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