Hi @ll !<br>
<br>
<br>
I would like to know if it is possible to perform a &quot;peer key
exchange&quot; prior to
the pairing operation, in order to for example, have the peers exchange
some extra information about them and be able for example to look-up
different PINs for every different service / connection / device.<br>
<br>
I have written a little program using rfcomm sockets (although I am
planing to change them to BNEP ones) which carries out the data
exchange without problems as long as the security manager is set to
'none'.<br>
<br>
But I would like to be able to replace the normal pairing procedure with this &quot;key exchange between bluetooth peers&quot; procedure: <br>
<br>
* it is then possible to trigger (maybe via 'pin_helper' ?) a data exchange
between the two bluetooth sockets (using raw L2CAP sockets, for example)
while the devices are _not paired_ and while the security level is set
at least to authentication ?<br>
<br>
* I tried to change the rfcomm &quot;working&quot; sockets program to L2CAP
sockets, but then I donīt know which&nbsp; Protocol Service MUX (psm)
value I might have to set for this sockets to have them connect
successfully (the one from an already existing service, one of the
reserved values?!). <br>
<br>
I tried different odd values greater than 1 for the psm (using htobs(psm)) and I get the following error message: <br>
<br>
Cannot connect to socket: Connection refused (111)<br>
<br>
I would really appreciate it if you could help me out or give me some advise on these topics.<br>
<br>
<br>
Best Regards,<br>
<br>
<br>
Jordi<br>