2007-04-22 18:47:54

by José Pedro Saraiva

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Subject: [Bluez-users] Max number of RFCOMM connections?

Hi all, can someone please enlight me on the following?

What is the maximum number of RFCOMM connections for each bluetooth dongle
with BlueZ?

Thanks in advance


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2007-04-24 02:29:46

by José Pedro Saraiva

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Subject: Re: [Bluez-users] Max number of RFCOMM connections?

Thanks all for the fast feedback and my apologies if my question wasn't
specific enough =)
I have one more doubt, though.

Knowing that each hci device suports 7 ACL, do SDP queries and hci scans
count as ACL when performed, even momentarely?


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2007-04-23 16:09:52

by Marcel Holtmann

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Subject: Re: [Bluez-users] Max number of RFCOMM connections?

Hi Manuel,

> > the answer is quite simple. Per ACL link between two devices you can
> > have 30 RFCOMM connections and another 30 one initiated by the other
> > device. Every piconet can have 7 ACL links and so you can do the math by
> > yourself.
> >
> I'm a bit confused :S. I thought you could only open 7 ACL on each
> device. So according to you I can get 7 ACL and then open up to 60
> RFCOMM over it right?. I guess the bandwidth will be divided between all
> those connections mhh it will be definitely to slow :D.

actually the bandwidth or 1 Mbit or 3 Mbit in case of EDR will also
divided between the 7 ACL links. And yes, the bandwidth will be shared.

Regards

Marcel



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2007-04-23 11:59:32

by Manuel Naranjo

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Subject: Re: [Bluez-users] Max number of RFCOMM connections?

Marcel
> the answer is quite simple. Per ACL link between two devices you can
> have 30 RFCOMM connections and another 30 one initiated by the other
> device. Every piconet can have 7 ACL links and so you can do the math by
> yourself.
>
I'm a bit confused :S. I thought you could only open 7 ACL on each
device. So according to you I can get 7 ACL and then open up to 60
RFCOMM over it right?. I guess the bandwidth will be divided between all
those connections mhh it will be definitely to slow :D.
Thanks,
Manuel

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2007-04-23 04:25:54

by Marcel Holtmann

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Subject: Re: [Bluez-users] Max number of RFCOMM connections?

Hi Manuel,

> Yes you are right, the question is quite tricky.

the answer is quite simple. Per ACL link between two devices you can
have 30 RFCOMM connections and another 30 one initiated by the other
device. Every piconet can have 7 ACL links and so you can do the math by
yourself.

Regards

Marcel



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2007-04-22 22:41:18

by Manuel Naranjo

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Subject: Re: [Bluez-users] Max number of RFCOMM connections?

Yes you are right, the question is quite tricky.
Cheers
> I totally agree with you, but I thought the question was about the
> maximum number of RFCOMM connections.
> When I said 30 I considered scenarios where there could be more than
> one RFCOMM connection between the same two ACL-connected devices...
>
> Actually, I have never implemented such scenario. I agree I am wrong
> if bluetooth doesn't allow to establish such a set of simultaneous
> connections...
>
> Loreno
>
> bluetooth dongle, according to the specs of the BT SIG. And RFCOMM is
> implemented over ACL, so you have a maximum of 7 simultaneous rfcomm
> connections.
> > I believe the maximum number of allowed connections relates to the
> > number of ports available to connect to using rfcomm.
> > Thus, my guess is 30.
> >
> >
> http://people.csail.mit.edu/albert/bluez-intro/x92.html#rfcomm-and-tcp
> >
> > Regards,
> >
> > Loreno
> >
> >
> > Hi all, can someone please enlight me on the following?
> >
> > What is the maximum number of RFCOMM connections for each
> > bluetooth dongle with BlueZ?
> >
> > Thanks in advance
> >
>
>
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>
> I'm sorry, that's not right. There's a maximum of 7 ACL connections per
>
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2007-04-22 22:36:10

by Loreno Oliveira

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Subject: Re: [Bluez-users] Max number of RFCOMM connections?

I totally agree with you, but I thought the question was about the maximum
number of RFCOMM connections.
When I said 30 I considered scenarios where there could be more than one
RFCOMM connection between the same two ACL-connected devices...

Actually, I have never implemented such scenario. I agree I am wrong if
bluetooth doesn't allow to establish such a set of simultaneous
connections...

Loreno

On 4/22/07, Manuel Naranjo <[email protected]> wrote:
>
> I'm sorry, that's not right. There's a maximum of 7 ACL connections per
> bluetooth dongle, according to the specs of the BT SIG. And RFCOMM is
> implemented over ACL, so you have a maximum of 7 simultaneous rfcomm
> connections.
> > I believe the maximum number of allowed connections relates to the
> > number of ports available to connect to using rfcomm.
> > Thus, my guess is 30.
> >
> > http://people.csail.mit.edu/albert/bluez-intro/x92.html#rfcomm-and-tcp
> >
> > Regards,
> >
> > Loreno
> >
> >
> > Hi all, can someone please enlight me on the following?
> >
> > What is the maximum number of RFCOMM connections for each
> > bluetooth dongle with BlueZ?
> >
> > Thanks in advance
> >
>
>
> -------------------------------------------------------------------------
> This SF.net email is sponsored by DB2 Express
> Download DB2 Express C - the FREE version of DB2 express and take
> control of your XML. No limits. Just data. Click to get it now.
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2007-04-22 22:21:29

by Manuel Naranjo

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Subject: Re: [Bluez-users] Max number of RFCOMM connections?

I'm sorry, that's not right. There's a maximum of 7 ACL connections per
bluetooth dongle, according to the specs of the BT SIG. And RFCOMM is
implemented over ACL, so you have a maximum of 7 simultaneous rfcomm
connections.
> I believe the maximum number of allowed connections relates to the
> number of ports available to connect to using rfcomm.
> Thus, my guess is 30.
>
> http://people.csail.mit.edu/albert/bluez-intro/x92.html#rfcomm-and-tcp
>
> Regards,
>
> Loreno
>
>
> Hi all, can someone please enlight me on the following?
>
> What is the maximum number of RFCOMM connections for each
> bluetooth dongle with BlueZ?
>
> Thanks in advance
>


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2007-04-22 19:28:46

by Loreno Oliveira

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Subject: Re: [Bluez-users] Max number of RFCOMM connections?

I believe the maximum number of allowed connections relates to the number of
ports available to connect to using rfcomm.
Thus, my guess is 30.

http://people.csail.mit.edu/albert/bluez-intro/x92.html#rfcomm-and-tcp

Regards,

Loreno

On 4/22/07, Jos? Pedro Saraiva <[email protected]> wrote:
>
> Hi all, can someone please enlight me on the following?
>
> What is the maximum number of RFCOMM connections for each bluetooth dongle
> with BlueZ?
>
> Thanks in advance
>
> -------------------------------------------------------------------------
> This SF.net email is sponsored by DB2 Express
> Download DB2 Express C - the FREE version of DB2 express and take
> control of your XML. No limits. Just data. Click to get it now.
> http://sourceforge.net/powerbar/db2/
> _______________________________________________
> Bluez-users mailing list
> [email protected]
> https://lists.sourceforge.net/lists/listinfo/bluez-users
>
>


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